Articles

Keywords: Deep-sea · Hydrocarbon seep · Sagami Bay · Diel rhythms · Internal tides · Automated video-image analysis · Zoarcid fishes · Eelpouts · Paralomis multispina · Buccinum soyomaruae

Behavioral rhythms in marine organisms are generally studied in coastal areas in relation to day-night and tidal cycles. In contrast, the presence of these rhythms in demersal deep-sea fauna remains poorly characterized at present due to technological constraints on direct observation and sampling repeatability. In this study, our aim was to determine the presence of tidally synchronized behavioral rhythms of the demersal fauna at a hydrocarbon seep in Sagami Bay (1100 m depth; central Japan) using automated video-image analysis. Time series of visual counts were obtained for eelpouts (zoarcid fishes), red crabs Paralomis multispina, and snails Buccinum soyomaruae. Water pressure data were used as a marker of internal tidal action. By fitting 24-h and 12-h Fourier harmonics onto 24-h time series segments, a power content value was obtained as a marker of diurnal and semidiurnal fluctuations within the biological data sets. Rhythms were stronger in eelpouts and were weaker in red crabs and snails. Visual counts of eelpouts peaked during spring phases with an infradian periodicity of 13 d. These results are discussed, taking into consideration that animal responses may be of a reactive type (i.e. exogenous) or may be controlled by a biological clock through putative hydrodynamic entrainment. Observed differences in the magnitudes of the rhythms were related to the different modes of species locomotion (i.e. swimming in eelpouts versus walking and crawling in red crabs and snails, respectively) in relation to seabed currents.

Keywords: Arctic – Zooplankton – Metabolism – Respiration – Excretion

The study of the structural and functional properties of key components of polar marine ecosystems has received increased attention in order to better understand the ecological consequences of future sea temperature rise and seasonal ice retraction. Owing to this purpose, during the ATOS-Arctic cruise, held in July 2007 in the framework of the 2007–2008 International Polar Year, we studied the respiratory carbon demand of mesozooplankton as well as their contribution to the regeneration of inorganic nitrogen and phosphorus (NH4-N and PO4-P) via excretion. The studied area comprised several stations along a latitudinal gradient in the East Greenland current, plus a network of stations NW of the Svalbard islands. The specific respiratory carbon losses and phosphorus (PO4-P) excretion rates were similar or slightly higher than some reports for Arctic mesozooplankton, but the nitrogen (NH4-N) excretion rates were higher by a factor of 3 when compared with previous data sets. The mesozooplankton respiratory losses were equivalent to 23% of primary production, and at turn zooplankton contributed by excretion to more than 50% of the N and P required by phytoplankton. Although C:N, C:P and N:P metabolic atomic quotients almost coincided with the average Redfield’s stoichiometric ratios, the low C:N values when compared to previous reports suggested a predominance of protein-related metabolic substrates. The potential consequences of changes observed in the C:N, N:P and C:P metabolic ratios of mesozooplankton for Arctic marine ecosystems are discussed.

Keywords: Ecosystem models; Plankton functional types; Data assimilation; Hydrodynamic models; Coastal zone processes; Model validation

The MarQUEST (Marine Biogeochemistry and Ecosystem Modelling Initiative in QUEST) project was established to develop improved descriptions of marine biogeochemistry, suited for the next generation of Earth system models. We review progress in these areas providing insight on the advances that have been made as well as identifying remaining key outstanding gaps for the development of the marine component of next generation Earth system models. The following issues are discussed and where appropriate results are presented; the choice of model structure, scaling processes from physiology to functional types, the ecosystem model sensitivity to changes in the physical environment, the role of the coastal ocean and new methods for the evaluation and comparison of ecosystem and biogeochemistry models. We make recommendations as to where future investment in marine ecosystem modelling should be focused, highlighting a generic software framework for model development, improved hydrodynamic models, and better parameterisation of new and existing models, reanalysis tools and ensemble simulations. The final challenge is to ensure that experimental/observational scientists are stakeholders in the models and vice versa.

Keywords: Nauplii · Oithona davisae · Growth · Development · Survival · Food · Temperature

Oithona spp. are probably the most abundant and ubiquitous copepods in the world’s oceans. However, knowledge of their development and growth rates is scarce compared to that of calanoid copepods. In the present laboratory study, we determined the survival, development and growth rates of the naupliar stages of Oithona davisae under different temperature regimes and food concentrations. Naupliar survival was reduced to approximately 60% at the lowest food concentration tested (11 µg C l–1 after 7 d at 20°C). The development of O. davisae nauplii was equiproportional, but not isochronal. Food concentrations required for maximum development and growth rates were 56 and 87 µg C l–1, respectively. The Q10 values for development and growth depended on the temperature range. O. davisae nauplii showed similar developmental times, but lower growth rates and food requirements than values reported in the literature for calanoid copepods. We suggest that these differences may help to explain the ubiquity of Oithona spp. in oceanic environments.

Keywords: Copepodite; Feeding; Gross growth efficiency; Growth; Nauplii; Oithona davisae

Among marine planktonic copepods, the genus Oithona is probably the most abundant and ubiquitous copepod in the world\'s oceans. However, knowledge about the ecophysiology of Oithonids is very scarce compared to calanoid copepods, particularly for their larval stages. We determined feeding rates and gross growth efficiencies of different developmental stages of the cyclopoid copepod Oithona davisae as related to food concentration, body weight and temperature in the laboratory. The feeding rates of nauplii and copepodites of Oithona davisae in relation to food concentration followed a type III functional response, with feeding threshold concentrations ranging from not, vert, similar 50 to 75 μg C L− 1, depending on the developmental stage. All feeding parameters varied according to body weight/age. The food concentration required to achieve the maximum ingestion rates increased from 200 μg C L− 1 in early nauplii to 320 μg C L− 1 in copepodites. Specific ingestion rates (d− 1) increased with increasing temperature, with a Q10 = 2.45. Growth rates were negatively related to larval size and positively related to food concentration and temperature. Gross growth efficiency ranged from 0.16 to 0.60 depending on the developmental stage, food availability and temperature. Oithona davisae developmental stages exhibited much lower maximum specific ingestion rates than calanoid nauplii but exhibited quite similar gross growth efficiencies. This indicates that Oithona nauplii should display lower metabolic losses and consequently lower food requirements than calanoid nauplii. Together with other factors, this feeding/energetic strategy may contribute to the success of the Oithona species in marine ecosystems of contrasting trophic characteristics.

The suitability of applying empirical conversion factors (eCFs) to determine bacterial biomass production remains unclear because seawater cultures are usually overtaken by phylotypes that are not abundant in situ. While eCFs vary across environments, it has not been tested whether differences in eCFs are driven by changes in bacterial community composition or by in situ environmental conditions. We carried out seawater cultures throughout a year to analyse the correlation between eCFs and bacterial community structure, analysed by catalysed reporter deposition fluorescence in situ hybridization. Gammaproteobacteria usually dominated seawater cultures, but their abundance exhibited a wide range (25–73% of cell counts) and significantly increased with inorganic nutrient enrichment. Flavobacteria were less abundant but increased up to 40% of cells counts in winter seawater cultures, when in situ chlorophyll a was high. The correlations between eCFs and the abundance of the main broad phylogenetic groups (Gamma-, Alphaproteobacteria and Flavobacteria) were significant, albeit weak, while more specific groups (Alteromonadaceae and Rhodobacteraceae) were not significantly correlated. Our results show that the frequent development of the fast-growing group Alteromonadaceae in seawater cultures does not strongly drive the observed variations in eCFs. Rather, the results imply that environmental conditions and the growth of specific phylotypes interact to determine eCFs.

Keywords: Arctic; bacteria; carbon; fixation; seawater

Although both autotrophic and heterotrophic microorganisms incorporate CO2 in the dark through different metabolic pathways, this process has usually been disregarded in oxic marine environments. We studied the significance and mediators of dark bicarbonate assimilation in dilution cultures inoculated with winter Arctic seawater. At stationary phase, bicarbonate incorporation rates were high (0.5–2.5 μg C L−1 d−1) and correlated with rates of bacterial heterotrophic production, suggesting that most of the incorporation was due to heterotrophs. Accordingly, very few typically chemoautotrophic bacteria were detected by 16S rRNA gene cloning. The genetic analysis of the biotin carboxylase gene accC putatively involved in archaeal CO2 fixation did not yield any archaeal sequence, but amplified a variety of bacterial carboxylases involved in fatty acids biosynthesis, anaplerotic pathways and leucine catabolism. Gammaproteobacteria dominated the seawater cultures (40–70% of cell counts), followed by Betaproteobacteria and Flavobacteria as shown by catalyzed reporter deposition fluorescence in situ hybridization (CARDFISH). Both Beta- and Gammaproteobacteria were active in leucine and bicarbonate uptake, while Flavobacteria did not take up bicarbonate, as measured by microautoradiography combined with CARDFISH. Within Gammaproteobacteria, Pseudoalteromonas-Colwellia and Oleispira were very active in bicarbonate uptake (ca. 30 and 70% of active cells, respectively), while the group Arctic96B-16 did not take up bicarbonate. Our results suggest that, potentially, the incorporation of CO2 can be relevant for the metabolism of specific Arctic heterotrophic phylotypes, promoting the maintenance of their cell activity and/or longer survival under resource depleted conditions.

Keywords: Cocolitóforos, sedimentos superficiales, biogeografía, Mediterráneo occidental, margen ibérico mediterráneo

en este trabajo se estudió la distribución de cocolitos en muestras de sedimentos superficiales del margen ibérico mediterráneo. Se calculó la abundancia total y se representó en un mapa de distribución. La mayor abundancia de cocolitos se registró en tres muestras situadas en los alrededores de las islas Baleares y se relacionó con los aportes de las aguas atlánticas modificadas más modernas (Modified Atlantic Water, MAW). La menor abundancia total se registró cerca de la costa, en el área de acción de la corriente del Norte (NC) y del frente Catalán y se ha relaiconado principalmente con los aportes terrígenos del río Ebro. Las abundancias relativas muestran que los pequeños placolitos (Emiliania huxleyi, Gephyrocapsa ericsonii) son las formas dominantes de la asociación de cocolitos en el Mediterráneo occidental, disminuyendo su abundancia con la distancia a la costa y relacionándolas con concentraciones de nutrientes. La distribución de Gephyrocapsa oceanica y Gephyrocapsa muellerae parece estar relacionada con la MAW de las proximidades del estrecho de Gibraltar y con alguno de los remolinos costeros generados por la corriente de Argelia (AC), respectivamente. Syracosphaera spp. y Helicosphaera spp. también alcanzan una abundancia significativa mostrando una distribución concéntrica en el mar Catalano-Balear. La distribución de Florisphaera profund, que mostró algunos valores más altos al sur del delta del Ebro, también puede ser de interés biogeográfico

Keywords: Alexandrium minutum, Mediterranean Sea, Resting cyst, Resuspension, Sediment dynamics, Seiche

The life cycle of the toxic dinoflagellate Alexandrium minutum consists of an asexual stage, characterized by motile vegetative cells, and a sexual stage, a resting cyst that once formed remains dormant in the sediment. Insight into the factors that determine the distribution and abundance of resting cysts is essential to understanding the dynamics of the vegetative phase. In investigations carried out between January 2005 and January 2008 in Arenys de Mar harbor (northwestern Mediterranean Sea), the spatial and temporal distribution patterns of A. minutum resting cysts and of the sediments were studied during different bloom stages of the vegetative population. Maximum cyst abundance was recorded mainly in the innermost part of the harbor while the lowest abundance always occurred near the harbor entrance, consistent with the distribution of silt-clay sediment fractions. The tendency of cysts in sediments to increase after bloom periods was clearly associated with new cyst formation, while cyst abundance decreased during non-bloom periods. Exceptions to this trend were observed in stations dominated by the deposition of coarse sediments. High correlation between the presence of cysts and clays during non-bloom periods indicates that cysts behave as passive sediment particles and are influenced by the same hydrodynamic processes as clays. In Arenys de Mar, the main physical forcing affecting sediment resuspension is the seiche, which was studied using in situ measurements and numerical models to interpret the observed distribution patterns. During non-bloom periods, cyst losses were smaller when the seiche was more active and at the station where the seiche-induced current was larger. Thus, seiche-forced resuspension appears to reduce cyst losses by reallocating cysts back to the sediment surface such that their burial in the sediment is avoided. The observed vertical profiles of the cysts were consistent with this process.

The SMOS (Soil Moisture and Ocean Salinity) mission of the European Space Agency (ESA) consists of a satellite with a L-band microwave synthetic aperture radiometer to retrieve ocean surface salinity (SSS) and soil moisture. Almost simultaneously, a second mission, this time from NASA, has been developed to produce a new salinity-sensing satellite, called Aquarius, that includes both a L-band radiometer and a scatterometer. While SMOS was launched November 2009, Aquarius is scheduled for launch in 2011. While the two satellites use different technological approaches that result in slightly different measurement resolutions, the issues regarding product generation and validation remain analogous. Some of the main technical issues to address for the proper intercomparison are: 1) the different spatial footprint that makes direct single image comparison difficult; 2) the need of image reconstruction algorithms; 3) the distinct noise levels expected; 4) the different spatial and temporal averaging scales needed for noise reduction; 5) the errors introduced by auxiliary data. Three primary interaction tasks are described: I) the identification of optimal/worse settings for each satellite based on the comparison with in situ and model data; II) the production of best estimates of satellite-measured global salinity maps using Optimal Interpolation; and III) the use of remote measurements in applications (e.g., involvement in the SPURS project to study the North Atlantic SSS maximum). SPURS (Salinity Processes in the Upper-ocean Regional Study) will try to characterize the main processes associated with the maintenance and evolution of the SSS maximum during an intensive field campaign to take place during 2012. SSS satellite information will help constrain the large-scale structure and its temporal evolution. Meanwhile, the availability of sufficient in situ observations will provide an outstanding opportunity for satellite data validation.

Keywords: Circulation model; Anticyclonic ring; Eddy evolution; Horizontal diffusion; Loop Current; Gulf of Mexico

The Colorado University Princeton Ocean Model (CUPOM) is used here to study the early stages in the life of Millennium, a mesoscale anticyclonic ring that detached from the Loop Current on April 2001 and lasted for more than 100 days. The numerical near-surface velocity field for the Gulf of Mexico is validated with the altimetry geostrophic velocities. The first 30 days of numerical data, before Millennium interacts with other mesoscalar features, are closely examined both from Eulerian and Lagrangian perspectives. During this time Millennium had a near-constant rotation period of 6.5 days, and particles do not leave the ring. Nevertheless, the distributions of temperature, salinity, and angular velocity confirm the existence of significant (possibly numerical) radial diffusion. Polar-coordinate phase plots for temperature–salinity anomalies and tangential–radial velocities, at several depths, illustrate the presence of an evolving oscillating pattern. Radial and tangential velocities change in phase, associated with vertical displacements of the isothermal and isohaline surfaces. A simple diffusion model with an effective diffusion coefficient of 200 m2 s− 1 is appropriate to grossly simulate the temporal evolution of angular velocity within Millennium.

Keywords: Sewage impact; Fish assemblages; Opportunistic species; Sensitive species; Visual census

The effects of sewage outfalls on subtidal fish assemblages were studied along the NW coasts of Malta (Sicily channel, Mediterranean Sea) by means of underwater visual census. The presence of two spatially distinct outfalls discharging untreated wastewaters allowed to use a balanced symmetrical after control/impact (ACI) design that consisted of two putatively impacted locations and two controls, with four sites nested in each location. Surveys were performed in 2006 at two random dates. The study highlighted significant changes at both assemblage and individual species levels. Fish assemblages structures were different between controls and sewages, where total abundance of fish were higher. The responses of individual species to sewage pollution were mostly related to an anomalous increase of two small opportunistic species i.e. Gobius bucchichii and Parablennius rouxi and to a decrease of species of the genus Symphodus, particularly S. roissali and S. ocellatus. Moreover in correspondence of the outfalls, significant changes of the fish size distribution were detected for several species. These results support the use of fish assemblages as biological indicators for marine coastal waters and demonstrated the possibility to obtain sharp signals of environmental impact from some individual fish species.

Keywords: percnon gibbesi, Percnide, Egypt, Mediterranean, invasive species

On July 2010, the invasive crab Percnon gibbesi was photographed and captured along the coast of Alexandria (Egypt, Eastern Mediterranean Sea). This represents the first observation of this species in Egyptian waters and the easternmost record for the southern rim of the Mediterranean.

Keywords: SMOS, Sea Surface Salinity, match-up, Level 3 and 4.

With the advent of ESA’s SMOS Mission, we have the opportunity for the first time of measuring Sea Surface Salinity (SSS) from the space and at a synoptic scale. However, the MIRAS instrument onboard SMOS is a new concept of instrument, and the adjustment and calibration of this interferometric radiometer poses great challenges. In this paper, we show the present status of Level 3 and 4 salinity maps, which are supposed to give accurate climatological descriptions of SSS, describing the attained accuracy and analyzing the geophysical consistence of those maps. A discussion on future improvements is also issued.

Keywords: Dissolved extracellular enzymatic activity, Prokaryotic heterotrophic production, Particulate organic matter, Deep ocean

The distribution of prokaryotic abundance (PA), prokaryotic heterotrophic production (PHP), and suspended particulate organic material (POM), as well as total and dissolved (operationally defined as passing through 0.2 µm pore size filters) potential extracellular enzymatic activities (EEA; α- and β-glucosidase [AGase and BGase], leucine aminopeptidase [LAPase], and alkaline phosphatase [APase]) were determined in the meso- and bathypelagic waters of the (sub)tropical Atlantic along an eastern zonal transatlantic transect and a western N-S transect. Significant differences between both transects were found for POM concentration but not for PA, PHP (except in the subsurface and oxygen minimum layer), and dissolved and total EEA. PHP decreased by 3 orders of magnitude from the lower euphotic zone to bathypelagic waters, while PA and cell-specific PHP decreased only by 1 and 2 orders of magnitude, respectively. The proportion of the dissolved to the total EEA was high in the dark ocean for all the enzymes, ranging from 54 to 100, 56 to 100, 65 to 100 and 57 to 97% for AGase, BGase, LAPase and APase, respectively. The kinetic parameters (Vmax and Km) of both the dissolved and total fractions of LAPase and APase were very similar throughout the water column, suggesting a similar origin for both dissolved and particulate EEA. Significant correlations of both dissolved and total EEA were found with prokaryotic metabolism and the POM pool. Based on the previous notion that the fraction of dissolved EEA is higher in particle-attached than in free-living microbes, our results suggest that microbial activity in the dark ocean occurs mainly on colloidal and particulate material. This is in agreement with recent genomic evidence. However, these colloidal and particulate materials are prone to disruption during the sampling process. Hence, more selective sampling techniques are needed to specifically collect these deep-water aggregates that probably represent hotspots of microbial activity in the deep ocean.

Keywords: Prokaryotic growth efficiency · Leucine-to-carbon conversion factor · Deep ocean

Experiments were conducted in the mesopelagic subtropical northeast Atlantic Ocean to determine the range of variability in the prokaryotic leucine-to-carbon conversion factor (CF), and prokaryotic growth efficiency (PGE). The way prokaryotic heterotrophic production (PHP) is calculated directly influences PGE (variations of PGE between 1 and 31% were found for a single sample). The empirically obtained deep-water CFs showed a 7-fold variability (0.13 to 0.85 kg C mol–1 Leu), but were always lower than the theoretical CF of 1.55 kg C mol–1 Leu assuming no isotope dilution. Empirically determined CFs were highly correlated to PGE, suggesting that both parameters are representations of the same basic metabolic processes. Overall, the PGEs obtained in this study suggest that mesopelagic prokaryotic assemblages can sometimes be as important in carbon processing as their epipelagic counterparts.

Keywords: Archaea; Bacteria; community composition; microbial activity; mesoscale eddy

To investigate the effects of mesoscale eddies on prokaryotic assemblage structure and activity, we sampled two cyclonic eddies (CEs) and two anticyclonic eddies (AEs) in the permanent eddy-field downstream the Canary Islands. The eddy stations were compared with two far-field (FF) stations located also in the Canary Current, but outside the influence of the eddy field. The distribution of prokaryotic abundance (PA), bulk prokaryotic heterotrophic activity (PHA), various indicators of single-cell activity (such as nucleic acid content, proportion of live cells, and fraction of cells actively incorporating leucine), as well as bacterial and archaeal community structure were determined from the surface to 2000 m depth. In the upper epipelagic layer (0–200 m), the effect of eddies on the prokaryotic community was more apparent, as indicated by the higher PA, PHA, fraction of living cells, and percentage of active cells incorporating leucine within eddies than at FF stations. Prokaryotic community composition differed also between eddy and FF stations in the epipelagic layer. In the mesopelagic layer (200–1000 m), there were also significant differences in PA and PHA between eddy and FF stations, although in general, there were no clear differences in community composition or single-cell activity. The effects on prokaryotic activity and community structure were stronger in AE than CE, decreasing with depth in both types of eddies. Overall, both types of eddies show distinct community compositions (as compared with FF in the epipelagic), and represent oceanic ‘hotspots’ of prokaryotic activity (in the epi- and mesopelagic realms).

It is generally assumed that sinking particulate organic carbon (POC) constitutes the main source of organic carbon supply to the deep ocean\'s food webs. However, a major discrepancy between the rates of sinking POC supply (collected with sediment traps) and the prokaryotic organic carbon demand (the total amount of carbon required to sustain the heterotrophic metabolism of the prokaryotes; i.e., production plus respiration, PCD) of deep‐water communities has been consistently reported for the dark realm of the global ocean. While the amount of sinking POC flux declines exponentially with depth, the concentration of suspended, buoyant non‐sinking POC (nsPOC; obtained with oceanographic bottles) exhibits only small variations with depth in the (sub)tropical Northeast Atlantic. Based on available data for the North Atlantic we show here that the sinking POC flux would contribute only 4–12% of the PCD in the mesopelagic realm (depending on the primary production rate in surface waters). The amount of nsPOC potentially available to heterotrophic prokaryotes in the mesopelagic realm can be partly replenished by dark dissolved inorganic carbon fixation contributing between 12% to 72% to the PCD daily. Taken together, there is evidence that the mesopelagic microheterotrophic biota is more dependent on the nsPOC pool than on the sinking POC supply. Hence, the enigmatic major mismatch between the organic carbon demand of the deep‐water heterotrophic microbiota and the POC supply rates might be substantially smaller by including the potentially available nsPOC and its autochthonous production in oceanic carbon cycling models.

Keywords: Total oxyradical scavenging capacity; Esterases; Lactate dehydrogenase oxidative stress; Organochlorine compounds; Mercury; Ardeida

Blood biomarkers and levels of major pollutants in eggs and feathers were used to determine pollution effects in nestlings of the Purple Heron Ardea purpurea and the Little Egret Egretta garzetta, sampled on three Ebro River (NE Spain) areas: a reference site, a site affected by the effluents of a chlor-alkali industry and the river Delta. The two impacted heron populations showed mutually different pollutant and response patterns, suggesting different sources of contamination. In the population nesting near the chlor-alkali plant, elevated levels of hexachlorobenzene (HCB) and polychlorobiphenyls (PCBs) in eggs, and mercury in feathers in A. purpurea chicks were related with reduced blood antioxidant defenses and increased levels of micronuclei. In Ebro Delta, high levels of plasmatic lactate dehydrogenase in A. purpurea chicks and high frequency of micronuclei in blood of both species were tentatively associated with intensive agricultural activities taking place in the area. These results provide the first evidence of a biological response in heron chicks to the release of pollutants at a chlor-alkali plant. High levels of organochlorine and mercury levels in eggs and feathers were related with altered blood biomarkers of heron nesting chicks.

Keywords: Coastal areas; HAB species; Mediterranean Sea; Monitoring; Ostreopsis; PCR

A molecular PCR-based assay was developed and applied to macrophyte and seawater samples containing mixed microphytobenthic and phytoplanktonic assemblages, respectively, in order to detect toxic Ostreopsis species in Mediterranean Sea. The specificity and sensitivity of the molecular PCR assay were assessed with both plasmidic and genomic DNA of the target genus or species using taxon-specific primers in the presence of background macrophyte DNA. The PCR molecular technique allowed rapid detection of the Ostreopsis cells, even at abundances undetectable within the resolution limit of the microscopy technique. Species-specific identification of Ostreopsis was determined only by PCR-based assay, due to the inherent difficulty of morphological identification in field samples. In the monitoring of the toxic Ostreopsis blooms PCR-based methods proved to be effective tools complementary to microscopy for rapid and specific detection of Ostreopsis and other toxic dinoflagellates in marine coastal environments.

Keywords: effects of climate change; coastal oceanography; thermal structure; thermal regime; mortality outbreak; positive temperature anomalies; Mediterranean; France; Spain; Gulf of Lions

In the North West Mediterranean (NWM), mass mortality events (MME) of long-lived benthic species that have occurred over the last two decades have been related to regional warming trend. Gaining robust data sets on thermal regimes is critical to assess conditions to which species have adapted, detect extreme events and critically evaluate biological impacts. High resolution temperature (T) time series obtained during 1999–2006 from 5 to 40 m depth at four contrasted sites of the NWM were analyzed: Area Marina Protegida de les Illes Medes (NE Spain), Riou (Marseilles, France), Parc National de Port-Cros (France), and Réserve Naturelle de Scandola (Corsica, France). The seasonal pattern showed winter T around 11–13 °C, and summer T mainly around 22–24 °C near surface to 18–20 °C at depth. Stratification dynamics showed recurrent downwellings (>40 m) at Medes, frequent observation (1/3rd of the summer) of deep and cold upwelled waters at Riou, while Scandola exhibited stable summer stratification and highest suprathermoclinal T. Port-Cros showed an intermediate regime that oscillated between Riou and Scandola depending on the occurrence of northern winds. Data distribution study permitted to identify and to characterize 3 large scale positive anomalies concomitant with the mass mortality outbreaks of summers 1999, 2003 and 2006. The analysis of biological surveys on gorgonian populations showed significant impacts during the 3 years with temperature anomalies. Besides the degree of impact showed inter-annual differences which could be related to different T conditions concomitant to mortality events, from slight increase in T extreme of only 1–2 °C over short duration, to lengthened more classical summer conditions. Our results therefore support the hypothesis that shallow NWM populations of long-lived benthic species are living near their upper thermal thresholds. Given actual trends and projections in NWM, the repetition of new MMEs in the next decades is extremely likely. In such context, the acquisition of dedicated high resolution T series proves to be crucial for increasing our detection, understanding and forecasting abilities.

The mechanisms underlying the population dynamics of species causing Harmful Algal Blooms (HABs) are complex because they result from the interplay of a spectrum of physico-chemical and biological factors, to which the organisms respond with a variety of strategies. Still, it is not clear whether the responses of harmful species are different from other phytoplankters. In order to resolve some of these questions, we started a multidisciplinary study in 2007 in Alfacs Bay (Ebre Delta), an active aquaculture site in the NW Mediterranean that is exposed to recurrent HAB events. Through a series of meteorological and hydrographical observations combined with modelling exercises, we try to understand how the circulation in the Bay affects the retention, dispersion, and thus the net development of (harmful) phytoplankton populations. The small-scale characterization of the physical water column properties is performed using a highresolution acoustic Doppler current profiler and a SCAMP (temperature microstructure profiler to deliver information about turbulence). With this approach, we aim to explain the observed preferential vertical concentration of the target organisms (harmful or not). The field studies are complemented by physiological research in the laboratory which has already shown a particular sensitivity of dinoflagellates to small-scale turbulence. For hypothesis testing, we combine these field and laboratory observations with an individual based (Lagrangian) turbulence model. Here, we present some of our progress and highlight our future goals which includes the deployment of a real-time automated physico-optical observation system to provide a better understanding of the in situ biological (growth and grazing rate) dynamics of (harmful) phytoplankton.

Keywords: Seismic oceanography; Thermohaline staircase layers; Mediterranean Undercurrent; Meddy; Boundary mixing; Gulf of Cadiz

Seismic images of staircase layers at the bottom of the Mediterranean Undercurrent with a lateral coherence up to 50 km and a horizontal resolution of View the MathML source are presented. The images show clearly the interaction between these staircase layers and other flow structures such as meddies, seamounts and internal waves. The staircase layers were imaged during two different surveys that used different sound sources. Comparison between seismic images and historical oceanographic observations illustrates the importance of using a seismic source adapted to the vertical scale of the oceanographic target to be imaged. Wavelengths larger than the size of the staircase structure distort the image in the vertical. For optimal imaging, deconvolution of the data is required.

Keywords: community, ecological indicators, ecosystem-based fisheries management, ecosystem effects of fishing, natural resource management

Time-series of ecological and exploitation indicators collected from 19 ecosystems were analysed to investigate whether there have been temporal trends in the status of fish communities. Using linear and non-linear statistical methods, trends are reported for six indicators (mean length of fish in the community, mean lifespan, proportion of predatory fish, total biomass of surveyed species, mean trophic level of landings, and inverse fishing pressure), and the redundancy of these indicators across ecosystems is evaluated. The expected direction of change for an ecosystem that is increasingly impacted by fishing is a decline in all indicators. A mixture of negative and positive directions of change is recorded, both within and among all ecosystems considered. No consistent patterns in the redundancy of the ecological indicators across ecosystems emerged from the analyses, confirming that each indicator provided complementary information on ecosystem status. The different trends in indicators may reflect differing historical exploitation patterns, management, and environmental regimes in these systems. Commitment to monitoring programmes and development of system-specific baseline, target, and threshold reference levels are required. Improved understanding of the responsiveness and performance of ecological indicators to management actions are needed to address adequately whether ecosystems are recovering from, or being further impacted by, fishing, and whether management targets are being met. The relative effects of multiple environmental and ecological processes as well as multiple human-induced stressors that characterize exploited ecosystems also need to be quantified.

Keywords: Aromatase; Sex differentiation; Sex determination; Brain; Neurogenesis

As fish are ectothermic animals, water temperature can affect their basic biological processes such as larval development, growth and reproduction. Similar to reptiles, the incubation temperature during early phases of development is capable to modify sex ratios in a large number of fish species. This phenomenon, known as thermolabile sex determination (TSD) was first reported in Menidia menidia, a species belonging to the family Atherinopsidae. Since then, an increasing number of fish have also been found to exhibit TSD. Traditionally, likewise in reptiles, several TSD patterns have been described in fish, however it has been recently postulated that only one, females at low temperatures and males at high temperatures, may represent the “real” or “true” TSD. Many studies regarding the influence of temperature on the final sex ratios have been focused on the expression and activity of gonadal aromatase, the enzyme involved in the conversion of androgens into estrogens and encoded by the cyp19a1a gene. In this regard, teleost fish, may be due to a whole genome duplication event, produce another aromatase enzyme, commonly named brain aromatase, encoded by the cyp19a1b gene. Contrary to what has been described in other vertebrates, fish exhibit very high levels of aromatase activity in the brain and therefore they synthesize high amounts of neuroestrogens. However, its biological significance is still not understood. In addition, the mechanism whereby temperature can induce the development of a testis or an ovary still remains elusive. In this context the present review is aimed to discuss several theories about the possible role of brain aromatase using fish as models. The relevance of brain aromatase and therefore of neuroestrogens as the possible cue for gonadal differentiation is raised. In addition, the possible role of brain aromatase as the way to keep the high levels of neurogenesis in fish is also considered. Several key examples of how teleosts and aromatase regulation can offer more insight into basic mechanisms of TSD are also reviewed.

Keywords: Viruses – Bacteria – Grazing – Viral infection – Arctic

During the last few years, extensive sea ice melting in the Arctic due to climate change has been detected, which could potentially modify the organic carbon fluxes in these waters. In this study, the effect of sea ice melting on bacterial carbon channelling by phages and protists has been evaluated in the northern Greenland Sea and Arctic Ocean. Grazing on bacteria by protists was evaluated using the FLB disappearance method. Lysis of bacteria due to viral infections was measured using the virus reduction approach. Losses of bacterial production caused by protists (PMMBP) dominated losses caused by viruses (VMMBP) throughout the study. Lysogenic viral production was detected in 7 out of 21 measurements and constituted from 33.9 to 100.0% of the total viral production. Significantly higher PMMBP and lower VMMBP were detected in waters affected by ice melting compared with unaffected waters. Consequently, significantly more bacterial carbon was channelled to the higher trophic levels in affected waters (13.05 ± 5.98 μgC l−1 day−1) than in unaffected waters (8.91 ± 8.33 μgC l−1 day−1). Viruses channelled 2.63 ± 2.45 μgC l−1 day−1 in affected waters and 4.27 ± 5.54 μgC l−1 day−1 in unaffected waters. We conclude that sea ice melting in the Arctic could modify the carbon flow through the microbial food web. This process may be especially important in the case of massive sea ice melting due to climate change.

Keywords: Phytoplankton, Population dynamics, Red tides, Paralytic shellfish poisoning, Spain, Galician rías

A study of Gymnodinium catenatum and Alexandrium minutum blooms on the Galician coast was conducted from 2005 to 2007 in order to increase knowledge of the mechanisms governing recurrent blooms of these species. Considerable differences in their bloom dynamics were observed. G. catenatum blooms occurred in autumn and winter, following the pattern previously reported in the literature: they began off-shore and were advected to the Galician rias when a relaxation of the coastal upwelling occurred. On the other hand, A. minutum blooms developed inside embayments in spring and summer during the upwelling season and were associated with water stability and stratification. Both the vegetative population and the cyst distribution of A. minutum were related to less saline water from freshwater river outputs, which support a saline-gradient relationship postulated herein for this species. Dinoflagellates may produce both long-term double-walled cysts (resting) and short-term pellicle cysts. Resting cyst deposition and distribution in sediments showed that seeding occurred during the blooms of both species. However, the relationship between the cyst distribution in the sediments in Baiona Bay and the intensity and occurrence of G. catenatum blooms, suggests that the latter are not directly related to resting cyst germination. Moreover, the results presented in the present study point to other difference between the two species, such as the detection of pellicle cysts only for A. minutum. Finally, we discuss how the life cycle strategies of these two species may help to explain the different mechanisms of bloom formation reported herein.

Keywords: Alexandrium minutum, Ecdysal cysts, Galician rías, Pellicle cysts, Spain, Temporary cysts

The terms “temporary”, “pellicle”, and “ecdysal” cyst have been employed arbitrarily in the literature of the dinoflagellate life cycle to describe a non-motile and single-layered-wall stage with no mandatory dormancy period, of asexual or sexual origin. These three terms have been used more or less synonymously, but more specific definitions, taking into account morphological and physiological aspects and their roles in dinoflagellate population dynamics, are still needed. To clarify the current terminology, we examine and discuss the usages and foundations of those terms. The background for this discussion is provided by a comparison of the morphology and germination times of three different types of Alexandrium minutum cysts collected during a seasonal bloom in the Bay of Baiona (NW Spain). The double-walled cysts were similar to the resting cysts reported for this species, but other, thin-walled and thecate cysts were also observed. These latter cyst types needed between 1 and 17 days to germinate and were therefore considered as short-term cysts, in contrast to the 1.5-month dormancy period of resting (hypnozygotic) cysts. Our results showed that the temporal distribution of these short-term cysts during the bloom period followed a pattern very similar to that of vegetative cells. However, resting cysts were only detected at the end of the bloom. In the context of our present knowledge regarding the dormancy and quiescence of dinoflagellate cysts, “temporary” is a very misleading and uncertain term and must be rejected. The term “ecdysal” has been used in reference to thin-walled cysts when ecdysis has been proven; however, ecdysis is not unique to this type of cysts as thick-walled zygotic cysts can be formed thorough ecdysis of a thecate planozygote. In conclusion, based on our current understanding of cysts, the term “pellicle” more appropriately describes single-layered-wall stages.

Keywords: RFI, SMOS probability of detection, probability of false alarm.

SMOS imagery has been analyzed to study: 1) radio frequency interference (RFI) detection and mitigation algorithms, and 2) the statistical properties of RFI. Results show that with a high probability of detection (-0.75), and probability of false alarm is very high as well (-0.68), and most snap-shots seem to be contaminated, even though the estimated RFI value is so weak, and the impact in the SMOS imagery is not even noticeable. Results of the detection and migration algorithm are presented, with the statistical analysis of more than 13000 L1b snap-shots.

Keywords: Individual energetic budget, Copepod, Food fluctuation, Egg production rate

A mathematical model of the individual budget of a spawning female of the copepod Acartia grani (Sars) has been used to simulate the time-scale of egg production over various external forcings (or inputs) of food fluctuation conditions. The budget matter in the body of the copepod females is distributed through four compartments: the whole digestive tract (globally named as gut), the hemolymph (which include the body fluid with available nutriments for the organs), the structural body weight, and the gonad. This small calanoid species does not carry lipid reserves but cumulate some labile reserves in its body, according to food availability. The model results show how the continuous spawning varies with food fluctuations, and suggest the mechanisms inducing the delay of response to starvation by using the metabolic reserves. Three different patterns in egg production response are observed: food fluctuations with frequencies below 12 h have no effect on egg production; food fluctuations of 12 h to 5 days induce synchronous egg production fluctuations; beyond 5 days the strong physiological changes induced by long starvation durations create delays in the responses to food replenishment. The available data of cultivated cohorts under laboratory conditions are used to validate the model. The properties underlined by the model, in particular its weak capacity to respond to starvation, allow explaining A. grani distribution in specific habitats. Different experimental protocols for complementary experiments are proposed to complete the model validation in other forcing conditions.

Keywords: Alexandrium minutum, Dinoflagellate, Flow cytometry, Harmful algal bloom, Immunofluorescence, Monoclonal antibodies

In recent years, Alexandrium minutum (A. minutum) has provoked repeated toxic episodes of harmful algal blooms. The existing method for accurate identification of this dinoflagellate is based on morphological traits and requires taxonomic expertise. However, this is impractical when rapid identification of toxic strains is required, when the microalgae are in low density or when automatic monitoring is needed. In this study, the generation and application of two monoclonal antibodies (M90.3 and M54.3) directed against an intracellular antigen of the A. minutum strain AL1V are described. Specificity and cross-reactivity were tested with cells from clonal cultures. In an immunofluorescence assay, confocal microscopy and flow cytometry showed that the antibodies specifically labeled the two tested A. minutum strains (AL1V and AMP13) and did not show cross-reaction with other Alexandrium species, such as Alexandrium tamarense SZN19, A. tamarense MDQ1096, Alexandrium catenella IEO715 and Alexandrium andersonii SZN12, or tested members of other phylogenetic classes. Furthermore, M90.3 showed highly specific recognition when used for the detection of A. minutum in natural seawater samples. Thus, the mAbs presented here could be used in microalgae monitoring, allowing a specific unequivocal identification of the toxic dinoflagellate A. minutum.

Keywords: Megabenthos; Suprabenthos/Zooplankton; Food and Feeding; Trophic Guilds; River Flows; Continental Slope; Submarine Canyons

The spatial and temporal changes of near-bottom macrofauna (suprabenthos and macroplankton) and the trophic relationships of megabenthic decapod crustaceans were analyzed off the Catalonian coasts (western Mediterranean) around Berenguera submarine canyon in four periods (April and December 1991, March and July 1992) and four zones (within Berenguera Canyon at ca. 450 m, and on adjacent slope at ca. 400, 600 m and 1200 m). In March 1992, we found the highest macrofauna abundance and the smallest sizes in the canyon, suggesting a positive effect of river discharges on suprabenthos recruitment. By contrast, macroplankton (decapods, fishes and euphausiids) did not show higher recruitment into canyons. After analyzing the diet of 23 decapod crustaceans, we found a significant segregation between guilds feeding on zooplankton and on benthos. Zooplankton (euphausiids and Pasiphaeidae) and infauna (polychaetes, Calocaris macandreae and ophiuoroids) were consistently the main prey exploited by decapod crustaceans around Berenguera Canyon. We also found some macrophyte (Posidonia oceanica) consumption, which was higher in periods of water column homogeneity (winter–spring and late autumn). Positive correlations between decapods\' gut fullness (F) and decapod abundance indicate feeding aggregations, while positive correlations were also found between F and Llobregat River (situated ca. 18 km from Berenguera head) flow 1 to 2 months before sampling. Increases in F were delayed only 1 month when zooplankton feeders were analyzed alone, while benthos feeders did not show significant relationships with any environmental variables. That indicates that the response of megabenthic decapods feeding on benthos to environmental shifts is slower than that of zooplankton feeders. The importance of river flows in enhancing food supply of macro- and megabenthos dwelling close to submarine canyons was apparent, with a delay in the fauna response of 0–2 months after river flow peaks.

Keywords: Engraulis encrasicolus; feeding; fish larvae; growth; Mediterranean; Aegean Sea

The objective of this work was to describe inter- and intra-annual variations in the environmental characteristics of the North-eastern Aegean Sea and to relate these changes to the egg and larval distributions, growth and feeding of larval anchovy (Engraulis encrasicolus). Four cruises, two in July and two in September in 2003 and 2004 were performed. The distributions of eggs and larvae were associated with i) salinity fronts related to the Black Sea Water and ii) shallow areas of high productivity over the continental shelf, some of them with high riverine influence. The first published description of the anchovy larval diet in the Eastern Mediterranean was conducted in individuals ranging from 2.2 to 17 mm standard length. The number of non-empty guts was relatively high (between 20% and 30%), and the diet was described through 15 main items. The mean size of the prey increased with larval size, and was generally dominated by prey widths smaller than 80 μm (mainly the nauplii and copepodite stages of copepods). Small larvae positively selected copepod nauplii. As larvae grew, they shifted to larger copepod stages. At all sizes, larvae rejected abundant taxa like cladocerans. The average trophic level calculated for anchovy of all size ranges was 2.98 ± 0.16 (SE). Growth rates varied from 0.41 to 0.75 mm d−1, with the highest growth rates generally observed in September. Variability in the Black Sea Water influence and the recorded inter- and intra-annual changes in primary and secondary production, combined with marked changes in temperature over the first 20 m depth, are used to frame the discussion regarding the observed significant differences in growth rates in terms of both length and weight.

Keywords: Nephrops norvegicus, circadian, entrainment , invertebrates, masking, deep sea

The temporal distribution of behavioral programs throughout the 24-h day, known as temporal niche of a species, is determined by ecological factors that directly affect the adaptive value of the timing of specific behaviors. Temporal niche switching has been described in several species and is likely adaptive in habitats where the daily timing of those factors changes. Benthic species whose habitats span a wide range of water depths are exposed to considerable depth-dependent environmental changes. Temporally scheduled trawl surveys of the Norway lobster, Nephrops norvegicus, reveal that animals emerge from burrows at night on the shallow shelf (10-50 m deep), at crepuscular hours on the lower shelf (50-200 m), and at daytime on the slope (200-400 m). The mechanisms underlying nocturnality/diurnality switches are chiefly unknown, and Nephrops offers a unique model for their study. The depth-dependent decrease in luminance is a likely candidate determining the temporal distribution of behavior. The authors explored this possibility in the laboratory by exposing Nephrops to light:dark (LD) cycles of 470-nm monochromatic lighting that mimic conditions at the 100-m-deep shelf (10 lux) or the 300-m slope (0.1 lux). Two groups of animals were respectively exposed to each light intensity according to the following protocol: an initial 12:12 LD stage followed by constant darkness (DD), followed in turn by a second 12:12 LD stage. Activity at the burrow opening (door-keeping = DK), as well as full emergence (E), was continuously monitored. Under 10-lux LD cycles, most animals showed nocturnal DK activity—with some being crepuscular or diurnal—and all animals showed nocturnal E activity. In contrast, both behaviors were clearly diurnal in animals under 0.1-lux LD cycles. The phase of the nocturnal and diurnal DK rhythms detected respectively at 10 and 0.1 lux upon release into DD revealed that these rhythms are entrained circadian rhythms. The present data indicate that nocturnality/diurnality switches in Nephrops in its natural habitat, evidenced by captures at different depths, are likely determined by light intensity. This temporal niche switching involves different patterns of photic entrainment, leading to bona fide circadian diurnal or nocturnal phenotypes, as well as exogenous masking of behavioral outputs.

Keywords: Heavy metals; Bioaccumulation; Ephoron virgo; Hydropsyche; Life cycle; Ebro River

This study focused on the metal bioaccumulation of two aquatic insects (Ephoron virgo and Hydropsyche spp.) in order to evaluate the spatial distribution of metals, the interspecific differences between both filter-feeders and the bioaccumulation dynamics during E. virgo development stages. Hg, Cd, Ni, Cr, As, Pb, Cu, Ti, Zn and Mn were quantified in insects and in suspended particulate matter (SPM) sampled downstream and upstream of a chemical plant, where more than 300,000 t of polluted sediments are deposited. Hg concentrations were one order of magnitude higher downstream of the sediment dump, which showed that the Hg pollution originated in the chemical plant. Cd, Ni, Cr, Pb, Ti, Zn and Mn in invertebrates revealed that metal pollution was present upstream in other parts of the river. Interspecific differences were observed for all metals but Mn; significantly higher concentrations were observed in E. virgo over Hydropsyche exocellata, except for Cd, which showed 10-fold higher values. Hg and Cd increased until E. virgo nymphs reached 11 mm and decreased afterwards in late instars when nymphs were about to emerge. Cr, Pb, Ti and Mn decreased along early instars followed by a steady state in late instars. Similar values were obtained for Cu, As and Zn along all instars. Sexual differences between males and females of E. virgo were observed for Cd, Cu and Mn. Hg and Cd persistence was strong across developmental stages since high concentrations were found in eggs and emerging adults. Because the behavior of different metals varied for the two species and during the developmental stages of E. virgo, care should be taken in the interpretation of insect metal concentrations when analyzing the food chain transfer of metals in river ecosystems.

The interaction between submesoscale baroclinic vortical structures and large amplitude inertia‐gravity waves (IGWs), with emphasis on the vertical velocity, is numerically investigated using a high‐resolution three‐dimensional non‐hydrostatic model. A rich variety of vortex‐wave interactions are possible depending on the potential vorticity (PV) content and length scale of the submesoscale monopoles or dipoles, and on the amplitude and wave number of the IGWs. On the one hand, large amplitude IGWs cause horizontal and vertical advection of the vortices, which conserve their stability though their geometry is largely modified by the wave motion. On the other hand, the horizontal vortical motion Doppler shifts the local frequency of IGWs. The vortical angular velocity and vortex density stratification lead to a wave dispersion relation involving the effective Coriolis frequency (Coriolis frequency plus the vortical angular velocity) and the total Brunt‐Väisälä frequency. This inhomogeneous change in the local wave frequency causes IGWs to depart from their initial plane geometry. In the particular case of inertial waves, the nonlinear vortex‐wave interaction generates spiral IGWs, having vertical velocities one order of magnitude larger than the submesoscale vortical flow in the absence of waves.

Keywords: comparative approach, ecosystem approach to fisheries, ecosystem indicators, fishing impacts, multivariate analysis, ranking techniques

A set of simple, data-based ecological indicators was used to rank exploited ecosystems regarding fishing impacts with respect to their status, trends, and ecosystem EAF attributes. Expected theoretical changes in indicators with respect to increasing fishing impacts were considered, and ecosystems were compared by examining the mean values of indicators in the most recent three years for which data were available and over time (1980–2005 and 1996–2005). Systems were classified into nine potential categories according to whether they were most, moderately, or least impacted, and whether they were becoming more or less impacted, or remaining stationary. The responses of ecological indicators to additional environmental and socio-economic explanatory factors were tested. Ecosystems ranked using short- and long-term trends and states differed because of differences in trends, underscoring the importance of analysing both states and trends in ecosystem analyses. The number of ecosystems classified as unclear or intermediately impacted has increased recently, the proportion of ecosystems classified as less strongly impacted has been maintained, but more now fall within the category more strongly impacted in terms of long-term trends and states. Ecosystem type, fisheries enforcement, primary production, sea temperature, and fishing type were important variables explaining the ecological indicators. The results reflect different changes and processes in the ecosystems, demonstrating that information on ecological, environmental, and fishery histories is crucial to interpreting indicators correctly, while disentangling the effects of fishing and of the environment.

The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet—undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of Gibraltar and the adjacent Alboran Sea), western African coast, the Adriatic, and the Aegean Sea, which show high concentrations of endangered, threatened, or vulnerable species. The Levantine Basin, severely impacted by the invasion of species, is endangered as well.

Keywords: Food-web model · Catch statistics · Biomass surveys · Trophodynamic indicators · Fishing impact · Environmental factors · Ecosystem-reference directions · Adriatic Sea · Mediterranean

We analyzed data from catch statistics, scientific surveys and results from ecosystem models to assess main changes in marine resources of the North-Central Adriatic Sea (Central Mediterranean) from the mid 1970s to the early 2000s. We then quantified food-web changes using these datasets and trophodynamic indicators. We applied time series trends and a Principal Component Analysis (PCA) to reduce the number of multivariate dimensions and to define ecosystem reference directions. To assess the correlation between ecological indicators and abiotic (human or environmental) factors, we used the non-parametric BIO-ENV procedure. Results illustrated a general decrease in the biomass and catch of target species with time, with a first phase of increasing catch and biomass of some organisms from the 1970s to the 1980s, a ‘fishing down the food web’ process during the 1980s, and a clear trend towards biomass and catch reductions during the late 1990s and early 2000s. These changes occurred in parallel with an increase in fishing effort and human development in the basin and changes in environmental factors such as an increase in the average annual sea water temperature, a decrease in the inflow of highly saline Mediterranean water into the Adriatic Sea, and changes in the atmospheric pressure at sea level. We found a high and significant correlation between ecological indicators and abiotic factors (in particular with human factors: fishing effort and the human development index). Results from the PCA summarized main ecosystem trends and could be used as a reference framework. These results complement traditional single-species fisheries assessments and inform on past trajectories and present ecological status of the North-Central Adriatic Sea.

Keywords: Sensory systems · Activity rhythm · Temporal segregation · Otolith · Eye · Anglerfish

The temporal segregation of 2 ecologically equivalent and sympatric species, the black anglerfish Lophius budegassa and white anglerfish L. piscatorius, was studied in relation to day–night behaviour and the underlying morphological variation in the sensory organs. Temporally scheduled trawl sampling was conducted on the western Mediterranean shelf, and diel fluctuations in catches were used as a proxy of behavioural rhythms. L. budegassa was more abundant at night than L. piscatorius, which mostly occurred in daytime catches. The observed differences in the timing of maximum activity (i.e. catches) were consistent with differences in otolith sagittae weight, eye/lens sizes and optical sensitivity. L. budegassa presented significantly heavier otolith sagittae than L. piscatorius, indicating that the behaviour of the black anglerfish is mostly acoustically driven (a typical characteristic of species living in dim light conditions). Preference for a dim light environment was also confirmed by the high optical sensitivity observed in this species achieved by enlarging the photoreceptors’ diameter. In contrast, L. piscatorius showed larger eyes and lenses than L. budegassa, but only in individuals larger than 50 cm. Large eyes usually improve photon capture and the fineness with which the image is sampled; however, relatively low values of sensitivity and resolution were observed in large L. piscatorius. This indicates that a trade-off might exist between the increase in eye size as an adaptive response to the impending deep meso- and bathypelagic life and a visual constraint imposed by the quality of the water at the bottom level where contrast can be degraded by suspended particles. These results indicate that interspecific competition with sympatric and ecologically equivalent species may result in different adaptations to diurnal/nocturnal behaviour, which are sustained by morphological specialisations in sensory organs.

Keywords: Lophelia pertusa; Stable isotopes; Vital effects; Cold-water corals; Trace elements

The aragonitic skeletons of bathyal cold-water corals have a high potential as geochemical in situ archives for paleoceanography. Oxygen isotopes and stable carbon isotopes (δ18O and δ13C) have been analyzed, as well as trace and minor element compositions (e.g. Mg/Ca, Sr/Ca, U/Ca, B/Ca and P/Ca) in Lophelia pertusa, one of the most important frame-builders at the Santa Maria di Leuca (SML) deep-water coral hotspot in the Central Mediterranean. The Apulian Bank is swept by strong currents of the Adriatic Deep Water Outflow. The temperature of 13.9 °C is the highest temperature recorded for L. pertusa and provides an important end-member of environmental conditions for geochemical analyses on living Atlantic and Mediterranean cold-water corals. Temperature and salinity (38.77 PSU) are stable throughout the year, and thus virtually no changes should be observed in the stable oxygen isotope signal—if the coral precipitates its skeleton in equilibrium with seawater. We measured various marine properties, such as the seawater oxygen isotope composition (δ18Osw), stable carbon isotope composition (δ13CDIC) of dissolved inorganic carbon (DIC), and dissolved inorganic nutrient concentrations (PO4, NO3, NO2, NH3 and SiO2). Bottom water at the coral sites shows a mean oxygen isotope composition of 1.47‰ δ18Osw-VSMOW, and δ13CDIC showed a mean of 1.1‰ VPDB. A section of a living L. pertusa with a thick theca calcification was probed with a Merchantek MicroMill at a high spatial sampling resolution with 10 samples per 1 mm. This reduced the signal-smoothing inherent to conventional sampling. The δ18Oag of coral aragonite ranges between −2.0‰ and +2.8‰ VPDB and the δ13Cag ranges between −7.77‰ and +1.47‰ VPDB. The Gaussian data distribution for both parameters, including heavy equilibrium values, suggests the completeness of the captured isotopic variability. The strict linear correlation of δ13C and δ18O displays a strong ‘kinetic’ vital effect. The intercept of the δ13C/δ18O correlation line with the δ13CDIC-composition permits recognition of δ18O equilibrium values of aragonite and thus reconstruction of water temperatures despite strong disequilibrium precipitation. Since the environmental parameters (T, S and δ18Osw) are stable, the entire isotopic signal of the coral must be driven by biological fractionation and might reflect growth speed variations, potentially related to pH variations and changes in the saturation state of the calcifying fluid or seasonally varying nutrient availability. Laser ablation tracks show a trace element composition dependent to microstructural zones (fibrous aragonite vs. centres of calcification). The parabolic relation of the classical temperature proxies Mg/Ca and U/Ca point to trace element vital effects, rendering them unreliable in L. pertusa. The P/Ca ratio shows similar values as Desmophyllum dianthus, for which a linear dependence with seawater phosphate (DIP) has been previously demonstrated. Consequently L. pertusa might be an additional nutrient recorder at bathyal depths. From the same site we also analysed the stable isotopic composition of the Last Glacial pectinid bivalve Pseudamussium peslutrae, which has been radiocarbon-dated (AMS-14C) at 26.3 ka 14C yr BP. The isotope values of the shell calcite document a strongly differing glacial temperature–salinity regime preceding the Holocene coral growth above a prominent hiatus.

The Census of Marine Life (2000–2010) was the largest global research programme on marine biodiversity. This paper integrated the findings of reviews of major world regions by the Census and provides a global perspective on what is known and what are the major scientific gaps. Study metrics were regional species richness, numbers of endemic and alien species, numbers of species identification guides and taxonomic experts, and a state-of-knowledge index. The threats to biodiversity were classified across the regions. A poor to moderate correlation between species richness and seabed area, and sea volume, and no correlations with topographic variation, were attributed to sparse, uneven and unrepresentative sampling in much of the global marine environment. Many habitats have been poorly sampled, particularly in deeper seas, and several species-rich taxonomic groups, especially of smaller organisms, remain poorly studied. Crustacea, Mollusca, and Pisces comprised approximately half of all known species across the regions. The proportion that these and other taxa comprised of all taxa varied sufficiently to question whether the relative number of species within phyla and classes are constant throughout the world. Overfishing and pollution were identified as the main threats to biodiversity across all regions, followed by alien species, altered temperature, acidification, and hypoxia, although their relative importance varied among regions. The findings were replicated worldwide, in both developed and developing countries: i.e. major gaps exist in sampling effort and taxonomic expertise that impair society\'s ability to discover new species and identify and understand species of economic and ecological importance. There was a positive relationship between the availability of species identification guides and knowledge of biodiversity, including the number of species and alien species. Available taxonomic guides and experts correlated negatively with endemic species, suggesting that the more we study the ocean the fewer endemic species are evident. There is a need to accelerate the discovery of marine biodiversity, since much of it may be lost without even being known. We discuss how international collaboration between developed and developing countries is essential for improving productivity in the discovery and management of marine biodiversity, and how various sectors may contribute to this.

Keywords: comparative genomics, primary production, prymnesiophytes, ,marine photosynthesis, haptophytes

Among eukaryotes, four major phytoplankton lineages are responsible for marine photosynthesis; prymnesiophytes, alveolates, stramenopiles, and prasinophytes. Contributions by individual taxa, however, are not well known, and genomes have been analyzed from only the latter two lineages. Tiny “picoplanktonic” members of the prymnesiophyte lineage have long been inferred to be ecologically important but remain poorly characterized. Here, we examine pico-prymnesiophyte evolutionary history and ecology using cultivation-independent methods. 18S rRNA gene analysis showed pico-prymnesiophytes belonged to broadly distributed uncultivated taxa. Therefore, we used targeted metagenomics to analyze uncultured pico-prymnesiophytes sorted by flow cytometry from subtropical North Atlantic waters. The data reveal a composite nuclear-encoded gene repertoire with strong green-lineage affiliations, which contrasts with the evolutionary history indicated by the plastid genome. Measured pico-prymnesiophyte growth rates were rapid in this region, resulting in primary production contributions similar to the cyanobacterium Prochlorococcus. On average, pico-prymnesiophytes formed 25% of global picophytoplankton biomass, with differing contributions in five biogeographical provinces spanning tropical to subpolar systems. Elements likely contributing to success include high gene density and genes potentially involved in defense and nutrient uptake. Our findings have implications reaching beyond pico-prymnesiophytes, to the prasinophytes and stramenopiles. For example, prevalence of putative Ni-containing superoxide dismutases (SODs), instead of Fe-containing SODs, seems to be a common adaptation among eukaryotic phytoplankton for reducing Fe quotas in low-Fe modern oceans. Moreover, highly mosaic gene repertoires, although compositionally distinct for each major eukaryotic lineage, now seem to be an underlying facet of successful marine phytoplankton.

We present results from a seismic refraction and wide‐angle experiment surveying an oceanic core complex on the Mid‐Atlantic Ridge at 22°19′N. Oceanic core complexes are settings where petrological sampling found exposed lower crustal and upper mantle rocks, exhumed by asymmetric crustal accretion involving detachment faulting at magmatically starved ridge sections. Tomographic inversion of our seismic data yielded lateral variations of P wave velocity within the upper 3 to 4 km of the lithosphere across the median valley. A joint modeling procedure of seismic P wave travel times and marine gravity field data was used to constrain crustal thickness variations and the structure of the uppermost mantle. A gradual increase of seismic velocities from the median valley to the east is connected to aging of the oceanic crust, while a rapid change of seismic velocities at the western ridge flank indicates profound differences in lithology between conjugated ridge flanks, caused by un‐roofing lower crust rocks. Under the core complex crust is approximately 40% thinner than in the median valley and under the conjugated eastern flank. Clear PmP reflections turning under the western ridge flank suggest the creation of a Moho boundary and hence continuous magmatic accretion during core complex formation.

Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth), including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes) reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components investigated (Prokaryotes excluded), most of the unknown species are within the phylum Nematoda, followed by Foraminifera, but an important fraction of macrofaunal and megafaunal species also remains unknown. Data reported here provide new insights into the patterns of biodiversity in the deep-sea Mediterranean and new clues for future investigations aimed at identifying the factors controlling and threatening deep-sea biodiversity.

Keywords: infralittoral environment, morphology, stratigraphy, Holocene, El Masnou

A detailed analysis of the morphology and the Holocene seismic and sequence stratigraphy and architecture of the infralittoral sedimentary environment of the El Masnou coast (Catalonia, NW Mediterranean Sea) was carried out using multibeam bathymetry and GeoPulse seismic data. This environment extends down to 26-30 m water depth, and is defined morphologically by two depositional wedges whose seafloor is affected by erosive furrows, slides, fields of large- and small-scale wavy bedforms, and dredging trenches and pits. Erosive terraces are also identified in the transition domain toward the inner continental shelf. The Holocene stratigraphy of the infralittoral environment is defined by two major seismic sequences (lower and upper), each one formed by internal seismic units. The sequences and units are characterised by downlapping surfaces made up of deposits formed by progradation of coastal lithosomes. The stratigraphy and stratal architecture, displaying a retrogradational arrangement with progradational patterns of minor order, were controlled by different sea-level positions. The stratigraphic division represents the coastal response to the last fourth-order transgressive and highstand conditions, modulated by small-scale sea-level oscillations (≈1-2 m) of fith to sixth order. This study also highlights the advantage of an integrated analysis using acoustic/seismic methods for practical assessment of the anthropogenic effects on infralittoral domains based on the association of marine geological observations.

Keywords: Messinian Saliniy Crisis, Alboran sea, Zanclean flooding, Atlantic water masses

The restoration of the Atlantic/Mediterranean c onnection through the Gibraltar Strait look place at eht end of Messinian Salinity Crisis and produced a huge flooding in a very short period of time, know as the Zanclean flooding. This catastrophic event priduced significant erosion along the Alboran Basin thet can be tracked eastward from the Gibraltar Strait till the transition to the Algero-Balear Basin. The interaction of the Atlantic water masses with the complex Messinian physiography sculpted an erosive corridor whose morphological characteristics vary along its pathway. At present-day, this eroisve corridor locally appears strongly deformed by Plio-Pleistocene tectonics and mud diapirism

Keywords: Alexandrium minutum, Cysts, Dinophyceae, Harmful Algal Blooms, Mediterranean Sea, Models

The role of resting cysts on the development of Alexandrium minutum blooms in a typical Mediterranean semi-enclosed water body (Arenys de Mar Harbor, NW Mediterranean) was studied by means of matrix and dynamic population models. We used a series of scenarios, constrained when possible by experimentally measured parameters to test whether excystment and encystment fluxes and changes in the dormancy period had a major effect on bloom intensity and duration. The results of the simulations highlighted the importance of knowing not only the magnitude and variability of growth and life-cycle transition rates, but also those of loss rates (both in the water column and in the sediment) due to physical or biological factors. Given the maximum encystment rates determined for A. minutum in the study area (0.01 d−1), this process contributed to reduce the peak concentrations of vegetative cells but did not have a dominant effect on bloom termination. Excystment fluxes could contribute to enhance population densities of vegetative cells during times or low or negative net growth rate and during the initial phases of a bloom, but once exponential growth had started, additional excystment had negligible effect on bloom magnitude. However, even if cysts did not contribute to larger blooms, they could represent a safety mechanism for reintroduction of the species when the vegetative cell population went extinct due to unfavorable environmental conditions. Increasing the dormancy time exposed newly formed cysts to a longer period of losses in the sediment that reduced the concentration of excystment-ready sediment cysts and decreased excystment fluxes. More complex models will be needed to explore the implications of different life-cycle strategies in a wider natural ecological context.

Keywords: Deep-sea invertebrates; Fixation; Food-webs; Formalin–ethanol; Stable isotopes

The aim of the present study was to quantify the effect of formalin–ethanol preservation on the carbon and nitrogen stable isotope values of five deep-sea species (Abra longicallus, Molpadia musculus, Sipunculus norvegicus, Chirimia biceps and Nephthys hystricis). To examine temporal changes in the effects of preservation and to determine if preservation induces predictable shifts in δ13C and δ15N values, analyses were carried out after 1, 6 and 12 months of preservation. The data indicated variable effects on carbon and nitrogen isotope values among species after formalin and ethanol preservation. Formalin fixation did not affect δ15N values of any of the five species analysed, while it did affect δ13C values, with a depletion trend observed in all of the species. In general ethanol preservation did not affect nitrogen values for up to 6 months of preservation, and only the δ15N values of S. norvegicus became depleted after 12 months. Ethanol fixation only affected the carbon isotopic composition of M. musculus, with a progressive depletion from 1 to 12 months after preservation. Due to the different effects of preservation on stable isotope values, the use of a general and systematic correction factor was not possible. Since no effect on δ15N values of either formalin or ethanol fixation is evident after 6 months, we recommend that these methods be used for short-term (< 6 months) conservation and only if studies are focused on the identification of trophic levels. If changes in carbon and nitrogen isotopic values from long-preserved samples are to be used for reconstructing a food web, it is necessary to establish the effects of preservation in the whole spectrum of species evaluated.

Keywords: benthic communities, diet, fishing effect, Pagellus erythrinus, stable isotopes, trophodynamics.

Because trawling disturbs benthic organisms, it could affect the diet of benthic-feeding fish with implications for food-web dynamics. The present study assessed the effects of commercial trawling on the trophodynamics and diet of pandora, Pagellus erythrinus, by comparing its stomach contents and stable-isotope (δ15N and δ13C) composition in two trawled and two untrawled gulfs in northern Sicily (central Mediterranean). Fish were collected on muddy bottoms at 50–100-m depth. Higher abundance and biomass and a slightly larger mean body length were found in the untrawled gulfs. The feeding habits were similar although more selective in the untrawled gulfs. The diet was mainly composed of decapod crustaceans (especially the brachyuran crab Goneplax rhomboides) and of polychaetes. The trophic level of pandora, estimated by its δ15N values, was higher in the untrawled gulfs. No clear trend between trawled and untrawled gulfs was found for the source of carbon in the diet (δ13C). The diet of a benthic feeder such as pandora may be used as an indirect indicator of trawling disturbance, as long as stomach contents and stable-isotope analysis are used jointly to assess the diet and trophodynamics of a species.

Keywords: Hoplostethus mediterraneus · Hymenocephalus italicus · Nezumia aequalis · Stomach contents · Stable isotopes · Mixing models · Temporal variations · Formalin preservation

Temporal variations in feeding habits and trophic levels of 3 deep-sea fishes: Hoplostethus mediterraneus, Hymenocephalus italicus and Nezumia aequalis, were investigated off the Archipelago of Cabrera (Algerian Basin). These species are representative of the 3 main trophic guilds found at bathyal depths: plankton feeders, suprabenthos feeders and epi-endobenthos feeders. Samples were collected during 6 trawl surveys at bi-monthly intervals from August 2003 to June 2004, between 550 and 750 m depths. Stomach content and stable isotope analyses were performed to detect temporal variations in diet. Because fish were immediately fixed in 10% formalin, a parallel experiment comparing isotope composition in fixed and freshly frozen tissues was carried out. H. mediterraneus mainly preyed on isopods throughout the sampling period and to a lesser extent on amphipods and mysids, although mixing models revealed high consumption of mesopelagic fish in winter and spring. H. italicus fed on mysids and amphipods that live in the benthic boundary layer, while N. aequalis exhibited a more benthic diet composed of benthopelagic and benthic prey (e.g. tanaids and polychaetes). Temporal variation was observed in the diet of H. mediterraneus, with February being the period of change in feeding habits. Temporal changes were also evident, though weaker than in H. mediterraneus, in the diets of the 2 macrourids, H. italicus and N. aequalis. Patterns of temporal change in fish diets follow temporal variations in prey, which are stronger in mesopelagic than in suprabenthic or benthic fauna. Temporal variations in tissue δ15N were detected in the 3 species, with the lowest values occurring in September and the highest in April to June. In general, different time lags were detected between the isotopic turnover time of consumers and that of their diets (prey) at a monthly time scale, showing that assimilation times depend on species behaviour and metabolism. Assimilation times are brief in H. mediterraneus but last up to 2 mo in the benthic feeder N. aequalis. The experiment comparing fixed versus frozen tissues showed that formalin did not affect δ15N values after 6, 12 and 24 mo of preservation, while δ13C signatures were depleted to different extents in the 3 species compared with controls.

The analysis of phytoplankton and environmental parameters of the Alfacs and Fangar bays time series (northwestern Mediterranean) Frrom 1990 to 2009 reveals certain trends. There is an increase in the average water column temperature by 0.11, 0.01, 0.80 and 23ºC for spring, summer, fall and winter respectively in Alfacs Bay and by 1.76, 0.71, 1.33, 0.89ºC for spring, summer, fall and winter in Fangar Bay. The trends in phytoplankton populations show a shift in the timing of occurrence of Karlodinium spp. blooms and an increase of Pseudo-nitzschia spp. abundance. There is no correlation between the average seasonal temperatures and toxic phytoplankton abundance

The Marine Strategy Framework Directive (2008/56/EC) (MSFD) requires that the European Commission (by 15 July 2010) should lay down criteria and methodological standards to allow consistency in approach in evaluating the extent to which Good Environmental Status (GES) is being achieved. ICES and JRC were contracted to provide scientific support for the Commission in meeting this obligation. A total of 10 reports have been prepared relating to the descriptors of GES listed in Annex I of the Directive. Eight reports have been prepared by groups of independent experts coordinated by JRC and ICES in response to this contract. In addition, reports for two descriptors (Contaminants in fish and other seafood and Marine litter) were written by expert groups coordinated by DG SANCO and IFREMER respectively. A Task Group was established for each of the qualitative Descriptors. Each Task Group consisted of selected experts providing experience related to the four marine regions (the Baltic Sea, the North-east Atlantic, the Mediterranean Sea and the Black Sea) and an appropriate scope of relevant scientific expertise. Observers from the Regional Seas Conventions were also invited to each Task Group to help ensure the inclusion of relevant work by those Conventions. This is the report of Task Group 5 Eutrophication.

Keywords: phototrophic biofilms, microbial diversity, DNA extraction, sulfide removal

hototrophic biofilms are used in a variety of biotechnological and industrial processes. Understanding their structure, ie microbial composition, is a necessary step for understanding their function and, ultimately, for the success of their application. DNA analysis methods can be used to obtain information on the taxonomic composition and relative abundance of the biofilm members. The potential bias introduced by DNA extraction methods in the study of the diversity of a complex phototrophic sulfide-oxidizing biofilm was examined. The efficiency of eight different DNA extraction methods combining physical, mechanical and chemical procedures was assessed. Methods were compared in terms of extraction efficiency, measured by DNA quantification, and detectable diversity (16S rRNA genes recovered), evaluated by denaturing gradient gel electrophoresis (DGGE). Significant differences were found in DNA yields ranging from 116 ± 12 to 1893 ± 96 ng of DNA. The different DGGE fingerprints ranged from 7 to 12 bands. Methods including phenol-chloroform extraction after enzymatic lysis resulted in the greatest DNA yields and detectable diversity. Additionally, two methods showing similar yields and retrieved diversity were compared by cloning and sequencing. Clones belonging to members of the Alpha-, Beta- and Gamma- proteobacteria, Bacteroidetes, Cyanobacteria and to the Firmicutes were recovered from both libraries. However, when bead-beating was applied, clones belonging to the Deltaproteobacteria were also recovered, as well as plastid signatures. Phenol-chloroform extraction after bead-beating and enzymatic lysis was therefore considered to be the most suitable method for DNA extraction from such highly diverse phototrophic biofilms.

Keywords: Alexandrium, DNA content, Flow cytometry, Karlodinium, Sexuality

The difficulties encountered in attempts to differentiate between dinoflagellate species of the genera Alexandrium and Karlodinium using morphological characteristics are well-known. For this reason, species of these genera were analyzed by flow cytometry to determine whether haploid DNA content served as a valid criterion for species identification. The DNA content of species often confused with each other due to their overlapping size and geographical occurrence, such as Alexandrium ostenfeldii and the complexes Alexandrium catenella, Alexandrium tamarense, Alexandrium minutum and Alexandrium tamutum, and Karlodinium veneficum and Karlodinium armiger were analyzed. These species differed greatly in DNA content, which provided a means of distinguishing among them. The only cases of DNA overlap involved A. ostenfeldii with Alexandrium peruvianum, and A. catenella with A. tamarense, two groups not yet clearly established either morphologically or genetically. Variability in intraspecies DNA content was observed only in the species K. veneficum. Significant differences between the two A. tamarense strains analyzed were not detected, and the haploid DNA content (63 pg cell−1) was very different from the one reported previously for this species (103.5 pg cell−1), suggesting cryptic speciation within this group. Flow-cytometric analysis of field samples identified K. veneficum as the causative species of a bloom, suggesting this method as a tool to readily identify species responsible for natural blooms. Additionally, after clonal cultures had been established, cytometric analyses corroborated the variability in the haploid DNA content of this species.

Keywords: Dinophyceae, Encystment, Gymnodinium catenatum, AFLPs, Sexual compatibility, Life cycle, Mating, Intraclonal genetic variation

The chain-forming dinoflagellate Gymnodinium catenatum Graham is responsible for outbreaks of paralytic shellfish poisoning (PSP), a human health threat in coastal waters. Sexuality in this species is of great importance in its bloom dynamics, and has been shown to be very complex but lacks an explanation. For this reason, we tested if unreported homothallic behavior and rapid genetic changes may clarify the sexual system of this alga. To achieve this objective, 12 clonal strains collected from the Spanish coast were analyzed for the presence of sexual reproduction. Mating affinity results, self-compatibility studies, and genetic fingerprinting (amplified fragment length polymorphism, AFLP) analysis on clonal strains, showed three facts not previously described for this species: (i) That there is a continuous mating system within G. catenatum, with either self-compatible strains (homothallic), or strains that needed to be outcrossed (heterothallic), and with a range of differences in cyst production among the crosses. (ii) There was intraclonal genetic variation, i.e. genetic variation within an asexual lineage. Moreover, the variability among homothallic clones was smaller than among the heterothallic ones. (iii) Sibling strains (the two strains established by the germination of one cyst) increased their intra- and inter-sexual compatibility with time. To summarize, we have found that G. catenatum\'s sexual system is much more complex than previously described, including complex homothallic/heterothallic behaviors. Additionally, high rates of genetic variability may arise in clonal strains, although explanations for the mechanisms responsible are still lacking.

Keywords: Alexandrium minutum; Cyst formation; Dinoflagellates; Local adaptation; Parvilucifera; Plastic response; Sexuality

A parasite threat stimulates adaptive shifts in the life-history strategy (sexual recombination rate) of the toxic bloom-forming dinoflagellate Alexandrium minutum Halim. This microalgae divides asexually when clonal but can also form mobile zygotes (planozygotes) when compatible clones are crossed. Planozygotes usually form resistant dormant stages (resting cysts) although they can also divide. In this study, asexual and sexual cultures were infected with the parasite Parvilucifera sinerae (Perkinsozoa) and the resulting clones classified as susceptible (S), low susceptible (LS), or resistant (R) to the infection. R and LS clones were never of Mediterranean origin, pointing to local adaptation of the parasite. (S × S) crosses were infected faster than either of the parental clones growing asexually. By contrast, (S × R) crosses were resistant to the parasite and produced no resting cysts, even when planozygotes were formed. Therefore, in infected cultures, the planozygotes mainly divided instead of encysting, thus increasing the rate at which recombinant progeny formed. This strategy against infection seems to combine the benefits of quickly producing asexual offspring and increasing recombination. As the susceptibility of the crosses was dependent on parental sexual compatibility, and cultures established by the division of (R × S) planozygotes (F1 offspring) also formed R or LS cultures, resistance may be regulated by several genes or through maternal effects.

Keywords: Aperture synthesis, imaging, microwave radiometry, remote sensing, salinity

Soil Moisture and Ocean Salinity, European Space Agency, is the first satellite mission addressing the challenge of measuring sea surface salinity from space. It uses an L-band microwave interferometric radiometer with aperture synthesis (MIRAS) that generates brightness temperature images, from which both geophysical variables are computed. The retrieval of salinity requires very demanding performances of the instrument in terms of calibration and stability. This paper highlights the importance of ocean salinity for the Earth\'s water cycle and climate; provides a detailed description of the MIRAS instrument, its principles of operation, calibration, and image-reconstruction techniques; and presents the algorithmic approach implemented for the retrieval of salinity from MIRAS observations, as well as the expected accuracy of the obtained results.

Keywords: Microwave radiometry, remote sensing, sea surface salinity

SMOS (Soil Moisture and Ocean Salinity), launched in November 2, 2009 is the first satellite mission addressing the salinity measurement from space through the use of MIRAS (Microwave Imaging Radiometer with Aperture Synthesis), a new two-dimensional interferometer designed by the European Space Agency (ESA) and operating at Lband. This paper presents a summary of the sea surface salinity retrieval approach implemented in SMOS, as well as first results obtained after completing the mission commissioning phase in May 2010. A large number of papers have been published about salinity remote sensing and its implementation in the SMOS mission. An extensive list of references is provided here, many authored by the SMOS ocean salinity team, with emphasis on the different physical processes that have been considered in the SMOS salinity retrieval algorithm.

SMOS (Soil Moisture and Ocean Salinity), launched in November 2, 2009 is the first satellite mission addressing the salinity measurement from space through the use of MIRAS (Microwave Imaging Radiometer with Aperture Synthesis), a new two-dimensional interferometer designed by the European Space Agency (ESA) and operating at L-band. This paper presents a summary of the sea surface salinity retrieval approach implemented in SMOS, as well as first results obtained after completing the mission commissioning phase in May 2010. A large number of papers have been published about salinity remote sensing and its implementation in the SMOS mission. An extensive list of references is provided here, many authored by the SMOS ocean salinity team, with emphasis on the different physical processes that have been considered in the SMOS salinity retrieval algorithm.

Mireya Masó mostly works in video and photography, and in recent years she has essentially concerned herself with the study of human beings through their action on the landscape. In her project ANTARCTICA. TIME OF CHANGE, however, she engages with a natural landscape barely touched by man, and focuses her investigations on the mechanisms of perception of the human being in an environment in continual transformation. The conversations between the artist and scientists from different disciplines provide the basis for a discussion in the book which considers questions such as Perception in the Antarctic environment in terms of glaciology, biology, psychology, neurology and other disciplines, and The interpretation of Antarctic microorganisms from the perspective of bionanotechnology and architecture.

Keywords: Jellyfish, Zooplankton, Climate, Israel, Spain

Blooms of the invasive ctenophore, Mnemiopsis leidyi, occurred in 2009 along the Mediterranean Sea coasts of Spain and Israel. This voracious zooplanktivore spread throughout the Black Sea basin after its introduction in the early 1980s, throughout northern European coastal waters, and now occurs throughout the Mediterranean Sea. M. leidyi occurred throughout the summer along the entire Catalan Spanish and Israeli coasts in 2009. Those locations had high temperatures (18–26C) and salinities (37–38) during the blooms. The patterns of abundance of large jellyfish along the Catalan coast were unusual in 2009, with low numbers during July, August, and September when ctenophores were abundant. Small populations of those potential predators and food competitors of M. leidyi could have contributed to the ctenophore bloom. The identity of the ctenophores from Spain and Israel was confirmed as M. leidyi by molecular analysis based on DNA sequencing of the nuclear internal transcribed spacer (ITS) regions. This is the first molecular confirmation of M. leidyi in the Mediterranean Sea. Most ctenophores had an ITS genotype previously found in M. leidyi from other invaded regions (the Black, Azov, and Mediterranean seas), as well as native regions in the United States, suggesting common ancestry. Based on the circulation patterns of Mediterranean surface waters and shipping activities, we conclude that the spread of M. leidyi in the Mediterranean probably resulted from re-introductions by ballast water transport and subsequent distribution by currents. We also conclude that the near-simultaneous blooms in opposite ends of both the Mediterranean basins indicate that M. leidyi is resident around the Mediterranean. We discuss environmental conditions, food, and predators of M. leidyi in both regions that would influence the future effects of this voracious consumer on the pelagic food web of the Mediterranean Sea.

ESA\'s Soil Moisture and Ocean Salinity (SMOS) satellite was launched on November 2nd, 2009 from Northern Russia. The SMOS single payload consists of a synthetic aperture radiometer operating at L-band (1.4 GHz). Once the commissioning phase was over, SMOS global calibrated brightness temperatures of the sea surface are now available. This paper presents a preliminary work to improve the definition of the Geophysical Model Function (GMF), which relates the sea emissivity on L-band with sea surface salinity (SSS) and other geophysical parameters. The GMF is a crucial ingredient in salinity retrieval, as it is used in the SMOS operational processor at DPGS. The GMF definition should be as simple (i.e., avoiding parameter cross-correlations) and efficient (i.e., representing the best fit of the measurements) as possible. Nevertheless, non-linear dependencies and wind direction effects need to be thoroughly examined in order to produce a quality product. In this paper, we will set the grounds for the future development of a fully empirical GMF, and we discuss the methodological issues to be considered in such a development.

We report a long-term (i.e., 4.5 consecutive yr) monitoring of surface marine archaeal assemblages of the coastal Mediterranean Sea using quantitative polymerase chain reaction against specific phylogenetic and functional genes, and, for some specific samples, clone libraries of the 16S ribosomal ribonucleic acid gene. Archaea had a marked seasonal periodicity, with recurrent peaks of abundance in December and January and very low occurrence during summer, parallel to temporal changes in community composition. Group II.b Euryarchaeota sequences were mostly present during winter when water was nutrient-enriched, and phytoplankton were abundant. Group II.a sequences were, in turn, more abundant during summer when the water column is stratified, and nutrient concentrations and phytoplankton stocks were lower. Group I Crenarchaeota abundance was highest during winter and significantly correlated with that of archaeal ammonia monooxygenase (amoA) gene copies and nitrite concentrations, suggesting that Group I Crenarchaeota were ammonia oxidizers. The periodicity of archaeal assemblages matched the strong and predictable seasonality of the surface-water conditions in the northwestern Mediterranean Sea, and suggests a low degree of functional redundancy between archaeal groups. The distinct seasonal dynamics for Group II.a and II.b Euryarchaeota, and their close association with major ecosystem processes, indicate that they may play an important but as yet largely unknown role in the ocean.

The distribution and cycling of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP) and dimethylsulfoxide (DMSO) were studied in the Greenland Sea and Arctic Ocean during July 2007. The concentration of these compounds was analyzed in vertical profiles of the top 100 m of the water column, with special emphasis on the subsurface (1 m) and the immediate subsurface waters (0.1 m). Seawater incubations were conducted in order to measure the rates of biological DMS cycling, as well as DMS photolysis rates. DMS ventilation rates were calculated from the hourly meteorological time series. Moderate concentrations of DMS (0.1 to 18.3 nM), DMSP (1.4 to 163.6 nM) and DMSO (9.0 to 84.7 nM) were found, considering that elevated biomasses of the haptophyte Phaeocystis pouchetii dominated in the study area. The overall situation was characterized by a tight coupling of biological DMS production and consumption, and a fast biological turnover of DMS (0.5 to 4 days). Bacterial consumption was the dominant sink for DMS, accounting for 9–73% of its loss in the upper mixed layer (UML). However, the shallow stratification encountered (mixed layer depth between 1.5 and 11 m) enhanced DMS photolysis, which accounted for 12–65% of the total DMS loss and, at some stations, became the dominant sink. DMS production followed phytoplankton biomass (and DMSP concentration) in surface waters, while bacterial DMS consumption was controlled by the depth of the UML (presumably through exposure to solar radiation). Ice melt drove surface stratification, regulating the entrainment of cells and materials into the upper layer from the more productive waters below, and eventually the fraction of DMS escaping to the atmosphere.

Keywords: Alexandrium, HAB, real-time quantitative PCR, ribosomal genes

A number of species belonging to the genus Alexandrium are among the main toxic microalgae responsible for Harmful Algal Blooms (HABs). The monitoring of coastal waters for the presence of these microalgae is essential to identify correlations between cell abundances and environmental factors that regulate bloom dynamics. In the attempt to improve the monitoring sensitivity and the rapidity at which a large number of field samples can be processed, several molecular methods for the detection of genetically distinct HAB species have been developed during the last years. In particular, real-time PCR has been shown to be a powerful method for quantitative detection of HAB species in environmental samples. When a plasmid is used as a standard, the knowledge of the amount of target gene per cell is essential for the determination of the cell number in the field sample. In this study, we analyzed the rRNA gene content variability in several Alexandrium catenella and Alexandrium taylori strains isolated from the Mediterranean Sea using a real-time PCR-based approach. The rRNA gene content was also analyzed in different growth phases, from early exponential to stationary conditions. The results showed a general variability in the rRNA gene content depending on the strain and, for the species A. taylori, in relation also to the growth phase. These results should be taken into account for the application of the real-time quantitative PCR-based techniques for monitoring purposes in coastal seawaters.

Keywords: Biodiversity, Biogeography, Life cycles, Toxic blooms, Dinoflagellates

Knowledge of phytoplankton species composition is important to understand bloom events in the coastal areas; it is also crucial to have information on the presence of novel and potentially introudced taxa and to confirm the recurrent events of a species. In the case of dinoflagellates, the alterntion between the life stages (vegetative and resting stage) has profound implications for population dynamics. Cyst assemblages in surface sediments represent a temporally integrated repertoire of species diversity. Therefore, cyst \"seedbed\" maps provide baseline information for monitoring purpose, to depict geographic patterns of harmful species, and to detect the introduction of new species.

Keywords: Apicomplexa; Dinoflagellates; Parvilucifera; Perkinsids; Ultrastructure

This ultrastructural study follows the infection by a parasite, Parvilucifera sinerae, of the marine toxic dinoflagellate Alexandrium minutum. In clonal cultures, infective zoospores, which are the infectious stage, entered host cells where they developed into sporangia. Mature, dark-colored sporangia were released from the dead dinoflagellate cells by the break-up of the host theca. The sporangial cytoplasm ultimately differentiated into many minute zoospores that escaped one host cell and subsequently infected healthy cells. The zoospores are 1.2–1.8 μm in diameter and possess an anterior (transverse) and shorter posterior flagellum in addition to alveoli, a refractile body, a mitochondrion with tubular cristae, micronemes, rhoptries, and a pseudoconoid. As in the other Parvilucifera species, the zoospore has a heteromorphic pair of central microtubules in the anterior axoneme and a reduced pseudoconoid. The micronemes have bulbous posterior ends and, as in other known species of the genus, there are (pseudo)conoid-associated micronemes. A comparison of these ultrastructural data with those available from the other two Parvilucifera species showed that, as in Parvilucifera infectans, the periphery of the nucleus is filled with thin fibers, in contrast to the syndinean-like nucleus of Parvilucifera prorocentri. Also, as in P. infectans, the transition region of the flagellar axoneme contains a dense structure, and the basal body a black globule; however, both structures are absent in P. prorocentri. There are no morphological differences of the zoospores from P. sinerae and P. infectans. The main difference between P. infectans and P. sinerae relay on the sporangium wall and ornamentation. The sporangium wall in P. sinerae consisted of three layers instead of two described layers in P. infectans. Therefore, morphologically, P. sinerae shows greater similarity to P. infectans than to P. prorocentri.

Keywords: Groundwater discharge, Inorganic nutrients, Karstic springs phytoplankton proliferations, Radium isotopes

Short and long-lived radium isotopes (223Ra, 224Ra, 226Ra, 228Ra) were used to quantify submarine groundwater discharge (SGD) and its associated input of inorganic nitrogen (NO3 −), phosphorus (PO4 3−) and silica (SiO4 4−) into the karstic Alcalfar Cove, a coastal region of Minorca Island (Western Mediterranean Sea). Cove water, seawater and groundwater (wells and karstic springs) samples were collected in May 2005 and February 2006 for radium isotopes and in November 2007 for dissolved inorganic nutrients. Salinity profiles in cove waters suggested that SGD is derived from shallow brackish springs that formed a buoyant surface fresh layer of only 0.3 m depth. A binary mixing model that considers the distribution of radium activities was used to determine the cove water composition. Results showed that cove waters contained 20% brackish groundwater; of which 6% was recirculated seawater and 14% corresponded to freshwater discharge. Using a radium-derived residence time of 2.4 days, a total SGD flux of 150,000 m3 year−1 was calculated, consisting of 45,000 m3 year−1 recirculated seawater and 105,000 m3 year−1 fresh groundwater. Fresh SGD fluxes of NO3 −, SiO4 4− and PO4 3− were estimated to be on the order of 18,000, 1,140 and 4 μmol m−2 day−1, respectively, and presumably sustain the high phytoplankton biomass observed in the cove during summer. The total amount of NO3 − and SiO4 4− supplied by SGD was higher than the measured inventories in the cove, while the reverse was true for PO4 3−. These discrepancies are likely due to non-conservative biogeochemical processes that occur within the subterranean estuary and Alcalfar Cove waters.

Keywords: Breeding decisions; Ecophysiology; H/L ratio; Leukocytes; Stable isotopes; Triglyceride

In long-lived seabirds, intermittent nonbreeding years in an adult life, the so called ‘sabbatical years’, are common. However, proximal causes that make animals decide whether to breed or not to breed are poorly known. In this study we assessed different components of the physiological state of a long-lived pelagic seabird, the Cory\'s shearwaters Calonectris diomedea, during the pre-laying period to understand which components are influencing breeding decisions. We analyzed plasma biochemistry, haematocrit, leukocyte counts and stable isotope (δ15N and δ13C) values in blood and claws. We also recorded body mass, ectoparasite loads and fault bars in primary and tail feathers. All parameters were compared between breeders and sabbaticals and between males and females. Among all biochemical variables analyzed we found triglyceride levels in plasma to be significantly greater in breeders than in sabbaticals and in females than males. H/L ratio was lower in breeders than in sabbaticals and greater in males than females. These results suggest the ability to store fat and the immunological condition are important components compromising breeding decisions. Our study also suggests that H/L ratio can be used as a good predictor of the breeding decisions.

Keywords: SMOS, Sea Surface Salinity, match-up, Level 3 and 4

With the advent of ESA’s SMOS Mission, we have the opportunity for the first time of measuring Sea Surface Salinity (SSS) from the space and at a synoptic scale. However, the MIRAS instrument onboard SMOS is a new concept of instrument, and the adjustment and calibration of this interferometric radiometer poses great challenges. In this paper, we show the present status of Level 3 and 4 salinity maps, which are supposed to give accurate climatological descriptions of SSS, describing the attained accuracy and analyzing the geophysical consistence of those maps. A discussion on future improvements is also issued.

Keywords: Aromatase; Cyp19a1a; Sex differentiation; Sex change; Fishes; Gonads; Estrogens

The present review focuses on the roles of estrogens and aromatase (Cyp19a1a), the enzyme needed for their synthesis, in fish gonadal sex differentiation. Based on the recent literature, we extend the already well accepted hypothesis of an implication of estrogens and Cyp19a1a in ovarian differentiation to a broader hypothesis that would place estrogens and Cyp19a1a in a pivotal position to control not only ovarian, but also testicular differentiation, in both gonochoristic and hermaphrodite fish species. This working hypothesis states that cyp19a1a up-regulation is needed not only for triggering but also for maintaining ovarian differentiation and that cyp19a1a down-regulation is the only necessary step for inducing a testicular differentiation pathway. When considering arguments for and against, most of the information available for fish supports this hypothesis since either suppression of cyp19a1a gene expression, inhibition of Cyp19a1a enzymatic activity, or blockage of estrogen receptivity are invariably associated with masculinization. This is also consistent with reports on normal gonadal differentiation, and steroid-modulated masculinization with either androgens, aromatase inhibitors or estrogen receptor antagonists, temperature-induced masculinization and protogynous sex change in hermaphrodite species. Concerning the regulation of fish cyp19a1a during gonadal differentiation, the transcription factor foxl2 has been characterized as an ovarian specific upstream regulator of a cyp19a1a promoter that would co-activate cyp19a1a expression, along with some additional partners such as nr5a1 (sf1) or cAMP. In contrast, upstream factors potentially down-regulating cyp19a1a during testicular differentiation are still hypothetical, such as the dmrt1 gene, but their definitive characterization as testicular repressors of cyp19a1a would strongly strengthen the hypothesis that early testicular differentiation would need active repression of cyp19a1a expression.

Keywords: Atmosphere Surface microlayer Sediment traps Sediment Air–sea exchange Deposition Fluxes PAHs Mediterranean Sea

Several measurements of polycyclic aromatic hydrocarbons (PAHs) in coastal marine compartments (viz.atmosphere, sea surface microlayer, subsurface seawater, sinking particles and sediments), made nearly simultaneously at two stations in the north-eastern Mediterranean, were used to estimate the transport fluxes of individual and total PAHs through the ai-seawater-sediment system. Diffusive air-sea exchange fluxes were estimated using both subsurface water (SSW) and sea surface microlayer (SML) concentrations. The air-SML fluxes ranged from 411 to 12,292 ng m-2d-1 (absorption) and from -506 to -13,746 ng m-2d-1 (volatilisation) for total PAHs (Σ15). Air-seawater column transport of particle-associated PAHs was estimated from the analysis of particulate atmospheric and sediment interceptor trap materials. Air-sea particle deposition fluxes of total PAHs ranged from 13 to 114 ng m-2d-1 and seawater particle settling fluxes (upper 5 m water column) ranged from 184 to 323 ng m-2d−1. The results of this study indicate that both the magnitude and the direction of the calculated air–sea diffusive fluxes change when PAH concentrations in the SML are considered. As a result, PAHs accumulation in the SML could produce the so-called “flux capping effect”. However, the high variability in the coastal air sea PAHs flux estimations, mainly due to the parameters uncertainty, requires further experimental approaches, including improvement of parameterisations.

Keywords: Pharmaceuticals and Personal Care Products Endocrine disrupting chemicals Molecular organic markers Sewage Transitional waters

An analytical method is described for the determination of a broad range of emerging and priority pollutants, together with sewage molecular markers in environmental waters. The step-by-step study of the GC/MS analyses focuses on the effects of experimental variables using a large volume injection (LVI) technique [a programmed temperature-vaporising (PTV) inlet], the evaluation of a clean-up step using classical and newer sorbents (i.e. Al–N, Fl, NH2, PSA, Si, CN and DIOL), and the revision of how organic matter [i.e. humic acids (HA) content] affects method performance. Reproducibility and recoveries from spiked coastal water samples at different analyte concentrations (100, 250 and 500 ng L-1) as well as with different levels of spiked humic acids (2, 10 and 20mgL-1) are reported indicating a good performance of the extraction procedure with low levels of HA (<10mgL−1). The presence of HA is a critical parameter during the solid-phase extraction (SPE) procedures. Of the clean-up sorbents tested, CN and DIOL proved most efficient in cleaning-up the extracts with recoveries in the range of 66-77% and 100-114%, respectively for the selected analytes. Both GC/MS and PTV-GC/MS instrumental configurations were tested using final sewage effluents, riverine, estuarine and coastal water samples. However, limited applicability of the PTV inlet is reported for environmental applications, affording only a modest improvement in chromatographic signal-to-noise ratios.

Keywords: Community structure; Phytoplankton growth; Microzooplankton grazing; Carbon flux; NW Mediterranean

The carbon flux through major phytoplankton groups, defined by their pigment markers, was estimated in two contrasting conditions of the Northwestern Mediterranean open ocean ecosystem: the spring bloom and post-bloom situations (hereafter Bloom and Post-bloom, respectively). During Bloom, surface chlorophyll a (Chl a) concentration was higher and dominated by diatoms (53% of Chl a), while during Post-bloom Synechococcus (42%) and Prymnesiophyceae (29%) became dominant. The seawater dilution technique, coupled to high pressure liquid chromatography (HPLC) analysis of pigments and flow cytometry (FCM), was used to estimate growth and grazing rates of major phytoplankton groups in surface waters. Estimated growth rates were corrected for photoacclimation based on FCM-detected changes in red fluorescence per cell. Given the 30% average decrease in the pigment content per cell between the beginning and the end of the incubations, overlooking photoacclimation would have resulted in a 0.40 d−1 underestimation of phytoplankton growth rates. Corrected average growth rates (μo) were 0.90±0.20 (SD) and 0.40±0.14 d−1 for Bloom and Post-bloom phytoplankton, respectively. Diatoms, Cryptophyceae and Synechococcus were identified as fast-growing groups and Prymnesiophyceae and Prasinophyceae as slow-growing groups across Bloom and Post-bloom conditions. The higher growth rate during Bloom was due to dominance of phytoplankton groups with higher growth rates than those dominating in Post-bloom. Average grazing rates (m) were 0.58±0.20 d−1 (SD) and 0.31±0.07 d−1. The proportion of phytoplankton growth consumed by microzooplankton grazing (m/μo) tended to be lower in Bloom (0.69±0.34) than in Post-bloom (0.80±0.08). The intensity of nutrient limitation experienced by phytoplankton indicated by μo/μn (where μn is the nutrient-amended growth rate), was similar during Bloom (0.78) and Post-bloom (0.73). Primary production from surface water (PP) was estimated with 14C incubations. A combination of PP and Chl a synthesis rate yielded C/Chl a ratios of 34±21 and 168±75 (g:g) for Bloom and Post-bloom, respectively. Transformation of group-specific Chl a fluxes into carbon equivalents confirmed the dominant role of diatoms during Bloom and Synechococcus and Prymnesiophyceae during Post-bloom.

Keywords: Polydora ciliata, low Reynolds number hydrodynamics, swimming behavior, prey selection

The behavior of the ubiquitous estuarine planktotrophic spionid polychaete larvae Polydora ciliata was studied. We describe ontogenetic changes in morphology, swimming speed and feeding rates and have developed a simple swimming model using low Reynolds number hydrodynamics. In the model we assumed that the ciliary swimming apparatus is primarily composed of the prototroch and secondarily by the telotroch. The model predicted swimming speeds and feeding rates that corresponded well with the measured speeds and rates. Applying empirical data to the model, we were able to explain the profound decrease in specific feeding rates and the observed increase in the difference between upward and downward swimming speeds with larval size. We estimated a critical larval length above which the buoyancy-corrected weight of the larva exceeds the propulsion force generated by the ciliary swimming apparatus and thus forces the larva to the bottom. This modeled critical larval length corresponded to approximately 1 mm, at which, according to the literature, competence for metamorphosis and no more length increase is observed. These findings may have general implications for all planktivorous polychaete larvae that feed without trailing threads. We observed bell shaped particle retention spectra with a minimum prey size of approximately 4 µm equivalent spherical diameter, and we found that an ontogenetic increase in maximum prey size add to a reduction in intra-specific food competition in the various larval stages. In a grazing experiment using natural seawater, ciliates were cleared approximately 50% more efficiently than similar sized dinoflagellates. The prey sizes retainable for P. ciliata larvae covers the microplankton fraction and includes non-motile as well as motile prey items, which is why the larvae are trophically positioned among the copepods and dinoflagellates. Not only do larval morphology and behavior govern larval feeding, prey behavior also influences the feeding efficiency of Polydora ciliata.

Keywords: Sistema Deposicional Contornítico, Contourite depositional system, Corriente Mediterránea de Salida, Mediterranean Outflow Water, Margen continental del norte de Iberia

This contribution aims to illustrate the Ortegal Cape Contourite Depositional System (OCCDS), a new example of contourites located on the northern Galicia margin generated by the Mediterranean Outflow Water (MOW) influence. This work is based on several datasets collected during two multidisciplinary cruises, including: single echosounder and swath bathymetry data, high and middle resolution reflection seismic profiles, sediment samples and CTD data. Both depositional and erosive features reflect an intense MOW interaction with the sea floor along the slope that has conditioned the occurrence of important local contouritic processes and the building of cold-water coral ecosystems.

Keywords: Continental shelf; Subaqueous dunes; Geomorphology; Swath mapping; Western Mediterranean

High-resolution multibeam swath-bathymetry and sediment samples were collected across the outer shelf region of the Columbretes Islands (southern Ebro continental shelf, western Mediterranean Sea). Bathymetric data from the submerged part of the Columbretes volcanic system revealed the presence of three main relict sand bodies along the outer shelf, at 80–116 m depth range, above which asymmetric and slightly asymmetric large and very large 2D and 3D subaqueous dunes were observed. These bed features were recognized, mapped and quantified with the aim of evaluating their potential formation mechanisms in relation to the local hydrodynamic and morphologic settings of the area. Dunes range from 150 to 760 m in wavelength and from tens of centimeters to 3 m in height, and are among the longest ever recognized in an outer shelf region. These bedforms are mostly composed of medium-sized sandy sediments, presumably coming from the degraded relict sand bodies on top of which they have developed, mixed with fine fractions from the recent draping holocenic sediments. The orientation of the dunes is SSW, progressively turning W towards the southernmost sector of the area, following the trend of the shelf-edge. Contemporary hydrodynamic measurements at the Ebro continental shelf-edge show that recorded currents are insufficient to form the observed bedforms and that stronger currents are required for sediment mobilization and dune formation. Based on their morphology and orientation, it is proposed that these bedforms are produced by the action of the southward-flowing Liguro-Provençal-Catalan (LPC) geostrophic current. The LPC probably reaches high near-bottom currents during energetic hydrodynamic events through interactions with the seafloor morphology of the study area. Subaqueous dunes are expected to be basically inactive features with respect to present-day processes, although they can be reactivated during high-energy events. The small Δh/λ ratio measured in the dune fields of the Columbretes shelf revealed that the dune heights fall below the values predicted by the Flemming (1988) global equation, as observed in other outer shelf settings also dominated by unidirectional flows. This may suggest a different morphodynamic character of large dunes formed on outer shelves in a micro-tidal regime.

Pockmark-like seabed features located on the Landes Plateau, Bay of Biscay, are depressions up to 1 km across and 50 m deep according to multibeam echo sounder data. Seismic (airgun and TOPAS) profiles show that each feature comprises a stack of identical features which extend down to 300 ms (twt). Three types of depressions, elongate, irregular and circular, appear as non-truncating V-shaped features in the Plio-Quaternary sediments. These features are located above the Parentis Basin where deep faults, basement ridges and diapiric bodies extend upwards across the sedimentary cover, providing ideal migration pathways for any buoyant fluids. Initial inspection suggests that these are classic pockmarks; however, the absence of reflection truncation and the absence of indications of shallow gas beneath the features indicate that they were not formed by the removal of sediment. These are “pockforms” but not “pockmarks”. This paper presents an explanation for the formation of these features, involving collapse and subsidence, sedimentary erosion, and only in some cases the erosion of seabed sediments by probable escaping fluids. These origins are mainly conducted through tectonic fluid dynamics which acted in the area up to the Late Miocene. It might be expected that these features would have been infilled by subsequent sedimentation, but their shape has been preserved because sedimentation in the area mainly comprised muds deposited from low-energy transportation (diluted gravity flows) and settling from hemipelagic suspension.

Keywords: Seston; Biogenic silica; Humboldt Current System; Upwelling; Lipids; Proteins

The biochemical composition of seston within the Humboldt Current System (HCS) in two bays off northern Chile (21°S–23°S) was assessed to estimate its chemical quality as potential food supply for benthic communities, large zooplankton and fish larvae. As part of the CENSOR project, in the summer of 2006 physical and biochemical variables were analyzed in Chipana and Mejillones Bays during one week at four depths determined by the occurrence of the upper boundary of the oxygen minimum zone and fluorescence peaks. The depth of the oxy- and pycnoclines controlled the distribution of biochemical variables in both bays. There were significant differences in the concentration of protein (PRT), lipid (LPD) and carbohydrates (CHO) among depths in both bays. The differences were also found in the PRT and LPD contribution to the biopolymeric carbon (BPC) among bays and among depths in the case of CHO. However, the concentration of suspended particulate matter and biogenic silica (bSi) were similar in both bays. PRT, LPD and CHO showed the highest concentrations in the upper meters of the water column and small peaks close to the seabed related to sediment resuspension and/or lateral transport. In Chipana Bay, the high nutritive quality of seston occurring near the seabed suggests a rapid sinking of diatom aggregates and a reduced respiration of the particulate organic matter. PRT, LPD and CHO varied between 0.05 and 0.47 mg l− 1, 0.06 and 0.39 mg l− 1 and 0.07 and 0.51 mg l− 1, respectively. LPD were the most important contributors to the BPC in both bays. The seston in these bays presented a high PRT and LPD content in comparison to a number of settings of different latitudes and oceanographic characteristics. The high quantity and biochemical quality of the particulate matter in both bays may reflect the high productivity of this zone and partially explain their condition as spawning areas within the HCS.

Small-scale turbulence affects the pelagic food web and energy flow in marine systems and the impact is related to nutrient conditions and the assemblage of organisms present. We generated five levels of turbulence (2*10–9 to 1*10–4 W kg–1) in land-based mesocosms (volume 2.6 m3) with and without additional nutrients (31:16:1 Si:N:P µM) to asses the effect of small-scale turbulence on the lower part of the pelagic food web under different nutrient conditions. The ecological influence of nutrients and small-scale turbulence on lower trophic levels was quantified using multivariate statistics (RDA), where nutrients accounted for 31.8% of the observed biological variation, while 7.2% of the variation was explained by small-scale turbulence and its interaction with nutrients. Chlorophyll a, primary production rates, bacterial production rates and diatom and dinoflagellate abundance were positively correlated to turbulence, regardless of nutrient conditions. Abundance of autotrophic flagellates, total phytoplankton and bacteria were positively correlated to turbulence only when nutrients were added. Impact of small-scale turbulence was related to nutrient conditions, with implications for oligotrophic and eutrophic situations. The effect on community level was also different compared to single species level. Microbial processes drive biogeochemical cycles, and nutrient-controlled effects of small-scale turbulence on such processes are relevant to foresee altered carbon flow in marine systems.

We used multiple approaches to analyze photosynthetic picoplankton (PPP) structure and production in a wetland in the Lower Paraná Basin (Argentina). A seasonal field survey was combined with an experimental study to analyze PPP variability under different light conditions. Flow cytometry analyses showed differences in PPP structure among the aquatic environments. Three main picoplankton populations were distinguished: phycocyanin-rich picocyanobacteria (Pcy), picoeukaryote (Peuk) and anaerobic anoxygenic photosynthetic bacteria (AnAnPB). The experimental study revealed important changes in PPP structure in relation to the light conditions imposed by floating plants: enclosures exposed to light showed a higher proportion of Peuk and Pcy over AnAnPB; in mesocosms covered by plants, just as in the highly vegetated relict lakes (ROLs), AnAnPB were dominant. Total picophytoplankton abundances varied from 1.7 x 104 to 4.6 x 105 cells mL–1 in the shallow lakes, and were lower (0.69 x 104 to 2.5 x 105 cells mL–1) in the ROLs. Annual variations in temperature and hydrological conditions influenced the PPP abundances, observing maximum values during the warm dry phase. The photosynthetic rates per unit area of PPP (PAPPP) and algae >3 µm (PA>3 µm) were measured in the aquatic environments in winter and summer: PA PPP (1.5 to 100 mg C m–2h–1) was lower than PA >3 µm and was directly affected by light, which was limiting under the dense floating plant cover.

Keywords: Distribution; Diversity; Open-ocean; Deep-sea; Near-bottom; Macroplankton; Hyperbenthos; Western Mediterranean; Spatio-temporal changes

We analyzed the distribution, diversity, and composition of western Mediterranean macroplankton (excluding gelatinous taxa) in the water column over depths of ca. 550–850 m, with special attention to near-bottom (0–1.5 and ca. 5–77 m above the bottom, mab) levels, and including data from three areas (off the coasts of Catalonia, and to the NW, and SE of Mallorca, Balearic Islands) in the period 1991–2008. Spatio-temporal changes in macroplankton abundance were evaluated as follows: (i) by seasonal sampling in 2007 off the Catalonian coast, (ii) by comparing Catalonian and Balearic Island slopes, and (iii) by comparing a fixed station on the Catalonian slope (at 550–800 m depth) at decadal (1991/1992–2007/2008) time scales. Diversity (in terms of species richness, S) was greater (i) at ca. 5–77 mab than at 0–1.5 mab, (ii) over the insular slopes of the Balearic Island (around Mallorca) than over the mainland Catalonian slopes, and (iii) in the period 1991/1992 than in 2007, likely related to higher values of the North Atlantic Oscillation (NAO) index in 1991/1992. In most analyses species composition was strongly influenced by the degree of stratification and homogenization of the water column in summer–autumn and winter–spring respectively and by location (longitude). Changes consisted mainly of higher density of macroplankton (e.g. abundance of the dominant euphausiids Nematoscelis megalops, Meganyctiphanes norvegica and Euphausia krohni and of the fish Cyclothone braueri) between June and October, parallel to an increase in the T and S close to the bottom. This coincided with changes in the flow of Levantine intermediate water (LIW) in the area. Aggregation of adult forms of the dominant species close to the bottom in summer–autumn could be favored because summer is the period of highest density of food – copepods, mainly Calanus helgolandicus – near the bottom off the Catalan slope. The formation of a thermocline in the water column and the reinforcement of the permanent thermohaline front at the shelf-slope break during summer at ca. 400 m in the Balearic Basin may also enhance this tendency toward greater aggregation of deep macroplankton under stratified water column conditions.

Keywords: ecological network, food web, host–parasitoid, mutualism, nestedness, null model

Questions: Are interaction patterns in species interaction networks different from what one expects by chance alone? In particular, are these networks nested – a pattern where resources taken by more specialized consumers form a proper subset of those taken by more generalized consumers? Organisms: Fifty-nine and 42 networks of mutualistic and host–parasitoid interactions, respectively. Analytical methods: For each network, the observed degree of nestedness is compared with the distribution of nestedness values derived from a collection of 1000 random networks. Those networks with nestedness values lower than 95% of all random values are considered ‘unusually nested’. The analysis considers two different metrics of nestedness and five different network randomization algorithms, each of which differs in the ecological assumptions imposed. Results: Most ecological networks are unusually nested when compared with loosely constrained random networks. Comparisons with highly constrained networks temper these findings, but we still report a significant preponderance of nested networks (typically those with the most species). Conclusions: Bascompte et al. (2003) previously showed most observed mutualistic networks to be unusually nested. Later work using more ecologically realistic randomization algorithms cast doubt on those results. Across the largest set of species interactions considered to date, we conclude that an unexpectedly large number of interaction networks are patterned in a non-random manner.

Keywords: EAF, ecological indicators, ecosystem effect of fishing, historical data, trawling surveys

Under the context of an ecosystem approach to fisheries (EAF), there is keen interest in providing insights into the evolution of exploited ecosystems using simple ecosystem indicators. Many nations have long-term scientific research surveys, originally driven by conventional approaches in fisheries assessment and management. The aim of this study is to address the practical concerns linked to current objectives of monitoring simple EAF indicators, using data from surveys that were not historically designed for the purpose. Based on the results of an expert survey designed to collect expert knowledge on research surveys from scientists working on different ecosystems worldwide, a list of challenges faced during indicator estimation is highlighted, along with associated concerns and constraints. The work provides additional information useful in the interpretation of the results obtained on the state and trends of ecosystems using EAF indicators by the IndiSeas WG. Further, the related discussion provides potential pathways that could be useful for future research and development aiming to improve the ecosystem indicator approach in the operational context of EAF. The question of the utility for EAF of using historical dataseries of scientific trawl series is also discussed. Such long-term series are concluded to be useful, that they are even inescapable (since the past cannot be resamplied), and that EAF therefore brings a supplementary reason for continuing such monitoring and to incorporate new insights in how research surveys may be conducted.

This work aims to compile knowledge on ecologically rich habitats that deserve special protection in the Mediterranean high seas. Many marine ecosystems are currently threatened by fishing activities, such as bottom trawling, gillnets and demersal and pelagic long-lines. Especially vulnerable are areas described as either sensitive habitats or essential fish habitats. Among these we highlight the associations of sessile organisms, such as cold coral reefs, mostly detected on continental slopes, seamounts and on the walls of submarine canyons, and those areas considered as hot spots of diversity and habitat of vulnerable fauna, like cold seeps, hydrothermal vents and submarine canyons. Essential habitats for pelagic species are defined by oceanographic features like productive areas associated with upwelling, and in the Mediterranean the spawning areas and migratory routes of bluefin tuna, swordfish, and albacore are of high conservation interest. We propose that in a context of difficult fisheries management in Mediterranean international waters, or high seas, these vulnerable habitats should be protected through the establishment of a web of Marine Protected Areas coordinated by all the involved countries and controlled by strict surveillance

Keywords: Engineered nanoparticles (ENPs), Bivalve, Haemocycle, Oxidate stress, Neurotoxicity, Cytotoxicity

Nano-Fe particle uptake was experimentally examined in vitro using excised gills and blood cells of the edible blue mussel Mytilus sp. Whole gills were exposed to both Fe(2)O(3) nanoparticles and a solution of the hydrated FeCl(3) salt, for up to 12 h, and blood cells for 30 min. Equimolar Fe(+3) in the nano- and the soluble form was estimated under the assumption of dense spherical particles accommodating the same number of Fe(+3) as in the dissolved salt solution, namely: 1,000 microg L(-1) Fe(2)O(3) equivalent to 100 microg L(-1) FeCl(3).6H(2)O. Putative toxic impact of nano-Fe in gill epithelia and blood cells was assessed by an array of techniques including light- and electron microscopy, biomarkers for oxidative stress (lipid peroxidation levels), neurotoxic effects (acetylcholinesterase activity) and cytotoxicity (neutral red retention). Total and filtered fractions (20 and 200 nm, respectively) of Fe were analysed by ICP-OES. Our results provide evidence for the following: (1) much of both the soluble (95%) and the nano-Fe (90%) were removed from the water column within 12 h; (2) dissolved- and nano-Fe seemed to follow different routes of uptake within the gill epithelium; (3) both nano-Fe and soluble FeCl(3) caused similar impairment of lysosomal stability in circulating blood cells; (4) lipid peroxidation in gills exposed to the two distinct forms of Fe was increased, while acetylcholinesterase activity was unaffected. In these short-term in vitro studies, there appears to be little difference in toxic response between exposure to the Fe salt and the nano-Fe indicating that, in this case, the nanoparticles do not invoke special properties affecting biological function in gills. However, with the use of nano-Fe as a food additive, clearly longer-term in vivo

Keywords: Interferometry; L-band; sea surface salinity (SSS); soil moisture; Soil Moisture and Ocean Salinity (SMOS); vegetation water content

It is now well understood that data on soil moisture and sea surface salinity (SSS) are required to improve meteorological and climate predictions. These two quantities are not yet available globally or with adequate temporal or spatial sampling. It is recognized that a spaceborne L-band radiometer with a suitable antenna is the most promising way of fulfilling this gap. With these scientific objectives and technical solution at the heart of a proposed mission concept the European Space Agency (ESA) selected the Soil Moisture and Ocean Salinity (SMOS) mission as its second Earth Explorer Opportunity Mission. The development of the SMOS mission was led by ESA in collaboration with the Centre National d’Etudes Spatiales (CNES) in France and the Centro para el Desarrollo Tecnologico Industrial (CDTI) in Spain. SMOS carries a single payload, an L-Band 2-D interferometric radiometer operating in the 1400–1427-MHz protected band [1]. The instrument receives the radiation emitted from Earth’s surface, which can then be related to the moisture content in the first few centimeters of soil over land, and to salinity in the surface waters of the oceans. SMOS will achieve an unprecedented maximum spatial resolution of 50 km at L-band over land (43 km on average over the field of view), providing multi- angular dual polarized (or fully polarized) brightness tem- peratures over the globe. SMOS has a revisit time of less than 3 days so as to retrieve soil moisture and ocean salinity data, meeting the mission’s science objectives. The caveat in relation to its sampling requirements is that SMOS will have a somewhat reduced sensitivity when compared to conven- tional radiometers. The SMOS satellite was launched success- fully on November 2, 2009.

The main goal of this study is the characterization of the salinity vertical structure in the proximity of the surface of the ocean. Both the World Ocean Database 2005 (WOD05) and the Argo floats are used. First, the data are horizontally averaged in appropriate size boxes (4ox4o) to contain sufficient statistical robustness. Vertical interpolation of observed level data to standard levels is carried out when necessary, following the standard procedures. Global maps of the mean salinity differences between the upper levels of the ocean highlight the regional differences in vertical salinity gradients. The results indicate that 10% of the salinity differences between 5 and 25m depth systematically appear to be greater than 0.2 psu. The distribution of salinity measurements between surface and a few meters in many regions is not Gaussian but skewed towards small salinity values.

This chapter introduces the Oceans from Space conferences held in Venice in 1980, 1990, 2000 and again now, in 2010. These events provide a once-a-decade review of progress in satellite oceanography. As satellite oceanographers, we have a unique view of some of the long-term environmental changes now apparent in the world. The present review introduces some of the significant long-term time series, which illustrate these changes, i.e. in carbon dioxide in the atmosphere, in land and ocean productivity, in sea surface warming, in sea-ice and ice-cap melting and in sea level rise. Meeting in Venice, we are also seeing the long-term direct reactions of a city increasingly threatened by rising sea levels. We look ahead to a possible next conference in 2020, when long-term trends may be clearer, and when worldwide action to reduce carbon emissions may have significantly intensified.

This Community White Paper (CWP) examines the present Sea Surface Salinity (SSS) observing system, satellite systems to measure SSS and the requirements for satellite calibration and data validation. We provide recommendations for augmenting the in situ observing network to improve the synergism between in situ and remote sensing measurements. The goal is have an integrated (in situ-satellite) salinity observing system to provide necessary the global salinity analyses to open new frontiers of ocean and climate research. It is now well established that SSS is one of the fundamental variables for which sustained global observations are required to improve our knowledge and prediction of the ocean circulation, global water cycle and climate. With the advent of two new satellites, the ocean observing system will begin a new era for measuring and understanding the SSS field. The SMOS (Soil Moisture and Ocean Salinity) and Aquarius/SAC-D (Scientific Application Satellite-D) missions planned to be launched between late 2009 and late 2010, are intended to provide ~150-200 km spatial resolution globally, and accuracy ~0.2 psu, or better, on monthly average. The challenge for the next decade is to combine these satellite and in situ systems to generate the optimal global SSS analysis for climate and ocean research. The in situ data provide surface calibration and validation for the satellite data, while the satellites provide more complete spatial and temporal coverage. The first priority is the maintenance of the existing in situ SSS observing network. In addition, we propose specific enhancements, ideally to include (1) deploying ~ 200 SSS sensors on surface velocity drifters and moorings in key regions, and (2) adding higher vertical resolution near-surface profiles to ~100 Argo buoys to address surface stratification, mixing and skin effects. Plans during the next few years to deploy a significant fraction of these enhanced measurements are identified.

Keywords: Spring bloom · Post-bloom · Stratification · Eutrophic conditions · Oligotrophic conditions

We examined the preferences of phytoplankton groups for waters of different trophic status by comparing the distribution of 8 main phytoplankton groups during the spring bloom, post- bloom, and late stratification periods in the northwestern Mediterranean. Pigment chemotaxonomy (using the CHEMTAX computer program) was applied to estimate the contribution of Prymnesio- phyceae, Pelagophyceae, Synechococcus spp., Prochlorococcus spp., Prasinophyceae, Crypto- phyceae, Dinophyceae, and Bacillariophyceae to the chlorophyll a (chl a) stock. Particulate organic nitrogen (PON) concentration was used as an indicator of trophic status. PON at the surface was 1.7 ± 1.4, 0.57 ± 0.02, and 0.37 ± 0.04 μmol l–1 in the bloom, post-bloom, and stratification periods, respec- tively. During the bloom period, there was a weak stratification and a large chl a biomass. Bacillario- phyceae dominated during the bloom period, with a substantial contribution of Prasinophyceae. Prymnesiophyceae and Synechococcus spp. dominated during post-bloom and stratification periods, and Prochlorococcus spp. was a major contributor to biomass in the deep chlorophyll maximum (DCM) during the stratification period. Vertical segregation was also evident for Pelagophyceae, Prymnesiophyceae, and Cryptophyceae, which preferred the DCM to surface layers in non-bloom conditions. The relative distribution of each group combined with PON concentrations in these 3 periods allowed us to calculate a group-specific trophic preference index, which showed its highest values (more eutrophic) for Bacillariophyceae, Prasinophyceae, Cryptophyceae, and Dinophyceae; medium values (mesotrophic) for Prymnesiophyceae, Pelagophyceae, and Synechococcus spp.; and a very low value (oligotrophic) for Prochlorococcus spp. The pigment-group diversity (Shannon index) and evenness were lower during the bloom period.

Keywords: benthic compartments; CaCO3 budget; carbon cycle; carbonate production; echinoderms; ocean acidification; standing stock.

The contribution of carbonate-producing benthic organisms to the global marine carbon budget has been overlooked, the prevailing view being that calcium carbonate (CaCO3) is predominantly produced and exported by marine plankton in the ‘‘biological pump.’’ Here, we provide the first estimation of the global contribution of echinoderms to the marine inorganic and organic carbon cycle, based on organism-level measurements from species of the five echinoderm classes. Echinoderms’ global CaCO3 contribution amounts to ;0.861 Pg CaCO3/yr (0.102 Pg C/yr of inorganic carbon) as a production rate, and ;2.11 Pg CaCO3 (0.25 Pg C of inorganic carbon) as a standing stock from the shelves, slopes, and abyssal depths. Echinoderm inorganic carbon production (0.102 Pg C/yr) is less than the global pelagic production (0.4–1.8 Pg C/yr) and similar to the estimates for carbonate shelves globally (0.024–0.120 Pg C/yr). Echinoderm CaCO3 production per unit area is ;27.01 g CaCO3m2yr1 (3.24 g Cm2yr1 as inorganic carbon) on a global scale for all areas, with a standing stock of ;63.34 g CaCO3/m2 (7.60 g C/m2 as inorganic carbon), and ;7.97 g C/m2 as organic carbon. The shelf production alone is 77.91 g CaCO3m2yr1 (9.35 g Cm2yr1 as inorganic carbon) in contrast to 2.05 g CaCO3m2yr1 (0.24 g Cm2yr1 as inorganic carbon) for the slope on a global scale. The biogeography of the CaCO3 standing stocks of echinoderms showed strong latitudinal variability. More than 80% of the global CaCO3 production from echinoderms occurs between 0 and 800 m, with the highest contribution attributed to the shelf and upper slope. We provide a global distribution of echinoderm populations in the context of global calcite saturation horizons, since undersaturated waters with respect to mineral phases are surfacing. This shallowing is a direct consequence of ocean acidification, and in some places it may reach the shelf and upper slope permanently, where the highest CaCO3 standing stocks from echinoderms originate. These organism-level data contribute substantially to the assessment of global carbonate inventories, which at present are poorly estimated. Additionally, it is desirable to include these benthic compartments in coupled global biogeochemical models representing the ‘‘biological pump’’ and its feedbacks, since at present all efforts have focused on pelagic processes, dominated by coccolithophores. The omission of the benthic processes from modeling will only diminish the understanding of elemental fluxes at large scales and any future prediction of climate change scenarios.

Keywords: conservation biology; Corallium rubrum; genetic clustering; isolation by distance; microsatellites

Combined action from over-harvesting and recent mass mortality events potentially linked to ongoing climate changes has led to new concerns for the conservation of shallow populations (5–60 m) of Corallium rubrum, an octocorallian that is mainly found in the Mediterranean Sea. The present study was designed to analyse population structure and relationships at different spatial scales (from 10s of meters to 100s of kilometres) with a focus on dispersal pattern. We also performed the first analysis of the distribution of genetic diversity using a comparative approach between regional-clusters and samples. Forty populations dwelling in four distinct regions between 14 and 60 m in depth were genotyped using 10 microsatellites. Our main results indicate (i) a generalized pair-sample differentiation combined with a weak structure between regional-clusters; (ii) the occurrence of isolation by distance at the global scale, but also within two of the three analysed regional-clusters; (iii) a high level of genetic diversity over the surveyed area with a heterogeneous distribution from regional-cluster to sample levels. The evolutionary consequences of these results are discussed and their management implications are provided.

Keywords: Corallium rubrum; dispersal; drift; heterozygote deficiency; kinship analysis; microsatellites; photogrammetry; spatial genetic structure

Identifying microevolutionary processes acting in populations of marine species with larval dispersal is a challenging but crucial task because of its conservation implications. In this context, recent improvements in the study of spatial genetic structure (SGS) are particularly promising because they allow accurate insights into the demographic and evolutionary processes at stake. Using an exhaustive sampling and a combination of image processing and population genetics, we highlighted significant SGS between colonies of Corallium rubrum over an area of half a square metre, which sheds light on a number of aspects of its population biology. Based on this SGS, we found the mean dispersal range within sites to be between 22.6 and 32.1 cm, suggesting that the surveyed area approximately corresponded to a breeding unit. We then conducted a kinship analysis, which revealed a complex half-sib family structure and allowed us to quantify the level of self-recruitment and to characterize aspects of the mating system of this species. Furthermore, significant temporal variations in allele frequencies were observed, suggesting low genetic drift. These results have important conservation implications for the red coral and further our understanding of the microevolutionary processes acting within populations of sessile marine species with a larval phase.

The Mediterranean coast receives large inputs of dust with a potential fertilization effect. We evaluated the effect of a wet dust deposition event on microbial abundance and activity, community structure and metabolic balance. Dust collected during a dust storm event was added to a series of microcosms. We added a realistic concentration (0.05 g L–1) based on the phosphorus concentration contained in the dust and, in addition, we included a P amended tank to distinguish the effect of dust from that of the phosphorus in the dust. We also included a higher dust concentration tank (0.5 g L–1). Dust increased the initial water–phosphorus concentration by 0.3 µM and the dissolved organic carbon (DOC) concentration by 14 µM, and increased bacterial abundance (1.8-fold) and bacterial production (5-fold). At the end of the experiment, primary production and community respiration were stimulated by dust and by P, but the net result of the addition of low amounts of dust was an initial switch towards heterotrophy, whereas the net result of the high-dust (DH) additions and the P addition was a shift towards autotrophy. Bacterial community structure changed little between P and low dust, but these were very different from the control and the DH communities.

Keywords: PAHs · Bacterioplankton · Production · Bacterial community structure · Mesocosms · Prestige oil

We studied the effects of the Prestige oil spill on Ría de Vigo bacterial abundance, production and community structure by using mesocosms (ca. 3500 l) filled with water from the center of the Ría, to which we added a realistic concentration of polycyclic aromatic hydrocarbons (PAHs; initial concentrations of approximately 20 to 30 µg l–1 chrysene equivalents) at each of the 4 periods of the seasonal cycle: spring bloom, summer stratification, autumn upwelling and winter. We followed the changes in bacterial activity by leucine and thymidine incorporation, and the changes in bacterial assemblage structure by 16S rDNA DGGE. In addition, simultaneously with the winter mesocosm experiment, we ran microcosms with fuel additions equivalent to 0.5, 1, 2 and 4× the treatment imposed on the mesocosms in the seasonal experiments. Bacterial community structure was also analyzed by CARD-FISH. We detected significant effects of the PAHs on bacterial community structure (increased number of bands) and production only in the summer experiment. In the microcosm experiments, we found similar effects to those in the mesocosms at PAH concentrations of ca. 20 to 40 µg l–1, and clear detrimental effects on phytoplankton at concentrations of ca. 80 µg l–1, with large development of Gammaproteobacteria. Our results indicate that an oil spill of the Prestige’s magnitude will have effects on the microbial resident community only at certain times of the year, while at higher PAH concentrations the effects might be more evident. For most of the year, the resident Ría de Vigo microbial communities appear to be accustomed to PAH concentrations such as those used in these experiments.

With the aim of designing photobioreactors (PBR) based on a smart exploitation of microalgae for the production of biofuels and metabolites of interest, this paper describes a novel approach where cyanobacteria are entrapped within highly porous silica matrices. With this concept, it would be possible to work with a constant population of organisms for a continuous (and increased) photoproduction of metabolites, in contrast to one-shot uses of liquid cultures. Different hybrid materials based on porous silica gels are described with a special emphasis on finding the most appropriate immobilisation conditions for prolonged cell survival. It is found that an aqueous route based on acid-exchanged sodium silicate combined with the use of silica nanoparticles as a gel-strengthening species shows the best results with a high primary production rate post immobilisation and a preservation of the photosynthetic pigments of up to 35 weeks. Oxygen production, though very low, could be evidenced up to 17 weeks after entrapment, demonstrating the suitability of using porous silica matrices in PBR design.

Keywords: Ascidian, Cibacapsa gulosa, Macrophagous, Prey items, Gut epithelium

Octacnemids represent a different pathway in the evolution of the typical filter-feeding ascidians. We examine and identify the prey items in the gut contents and describe the cell types that constitute the inner wall of different sections of the gut of the macrophagous octacnemid Cibacapsa gulosa collected in the South Sandwich Islands, Antarctica. A great variety of prey items were found: polychaetes, copepods, halacarids, amphipods, isopods and ophiuroids. The internal wall of the gut is lined with a monostratified, prismatic epithelium. Different cell types occur in the inner wall in different sections. The presence of zymogenic cells throughout the internal gut epithelium, as well as the presence of concretion cells in the stomach of C. gulosa, also present in the macrophagous tunicate group Sorberacea (= Hexacrobylidae), can be considered as an adaptation to the macrophagous diet.

Keywords: Mass-balance model; Marine protected areas; Trophic structure; Ecosystem functioning; Fishing effects; Adriatic Sea; Mediterranean Sea

This study presents a comparative analysis of protected and exploited Mediterranean Sea food webs using standardized ecological models of two ecosystems: the Central-North Adriatic Sea (highly exploited) and the Miramare Natural Marine Reserve (Northern Adriatic Sea, protected since 1986). Food webs are analysed in terms of structural and functional traits including trophic levels, transfer efficiency, trophic role of species and keystoneness, trophic spectra and other synthetic ecological indicators. Our results highlight similarities between food webs of the Adriatic Sea, differences that are likely due to the impact of fishing and differences that should be related to other factors. Analysis of biomass distribution along functional groups and of trophic spectra indicates that protected area presents higher mean trophic level of the community, higher biomasses, lower production and generally lower transfer efficiency than fished area. Our results indicate that measures of food web complexity (system omnivory index and ascendency), as well as pelagic/demersal and fish/invertebrates biomass ratios are higher in the protected area than in exploited ecosystem due to fishing-induced changes. Thus, this study highlights that marine protected areas can efficiently contribute to maintain structural and functional traits of marine ecosystems.

Coralligenous communities are an important “hot spot” of Mediterranean biodiversity. These communities are presently threatened by a combination of anthropogenic impacts partly related to global change. Managers of MPAs are increasingly concerned about the capacity of coralligenous communities to endure crowds of divers, and there is a call for descriptors and for quantitative methods for estimating this capacity. A good indicator to detect the impacts on coralligenous communities should gather the following essential traits: to be a long-lived, clonal, engineering species displaying an erect shape and a large size in order to facilitate the monitoring. Among the main taxonomic groups of the coralligenous, gorgonians display several advantages and, in this study, the red gorgonian Paramuricea clavata was selected as a model species to evaluate the effects of diving impact and climate change on coralligenous communities. We present three cases of study about the demographic monitoring of red gorgonian populations affected by the 1999 mass mortality event (Port-Cros) and subjected to high diving activity (Medes Islands and Cap de Creus). Finally, combining all these data we simulate the interacting effects of divers damage and mass mortality events on the persistence of gorgonian populations. The results of long-term monitoring of permanent plots allowed showing that although diving activity affects significantly the red gorgonian populations, the effect of climate change has more significant effects on the populations. Port-Cros populations affected by the 1999 mass mortality suffered a 60% biomass loss that has not been recovered in the following eight years. Simulations showed that the combination of both disturbances can have large and lasting effects on the future viability of red gorgonian populations. As gorgonian assemblages are only one facies of the coralligenous communities, other species should be selected for detecting the impact on these communities. Nevertheless, the development of similar demographic approaches for other species would be more difficult than for gorgonians.

Keywords: Corallium rubrum · Coral fisheries · Marine Reserves · Size frequency distributions · NW Mediterranean Sea

Intensive harvesting has caused important shifts in the size structure of the Mediterranean red coral Corallium rubrum, and continues to hinder the total recovery of exploited populations. Marine Protected Areas (MPAs) offer an excellent opportunity to observe their recovery in the absence of fishing pressures. In this study, we analysed the demographic structure of red coral populations from 3 of the oldest Mediterranean MPAs. The population structures at the beginning of each reserve and after 30 yr of similar management efforts were also forecasted. The 3 MPAs displayed higher size values than those reported for most of the shallow populations and deep-dwelling populations. Differences in the observed size distributions were more closely related to the structure at the beginning of the reserve than to the number of years of protection. The estimated future size distributions showed a significant increase in large colonies; however, the maximum values predicted are far from those measured in pristine populations. Comparisons of harvested and protected populations using different parameters allowed us to identify the percentages of colonies with basal diameter greater than 7 mm or colony height greater than 100 mm as the most useful descriptors for evaluating the conservation status of each population. The vulnerability of long-lived marine invertebrates to disturbances is due to their slow population dynamics, hence the importance of active management within MPAs to promote delayed but long-term positive effects on these species. This study provides helpful information for the evaluation of the effectiveness of management measures for coral populations.

Keywords: Jellyfish, submersible, Shinkai 2000, Cnidaria, trachymedusa, new species, Suruga Bay, Japan, commensal amphipod

Large numbers of a distinctive trachymedusa were observed at 1967 m depth just above the bottom in Suruga Bay, Japan, during a dive by the crewed submersible Shinkai 2000 in April 2002. Two individuals were collected and proved to be an undescribed species, herein described as Voragonema tatsunoko sp. nov. This species is characterised by the number (9) and shape of the centripetal canals. An immature male hyperiid amphipod, Mimonectes spandli Stephensen and Pirlot, 1931, was observed attached to the subumbrella of one of the individuals adjacent to a gonad. This is the first record identifying an association between another organism and M. spandli and is the first record of this amphipod species outside of the Atlantic Ocean.

Keywords: climate change, ecosystem approaches to fisheries, ecosystem dynamics, fisheries, indicators, multivariate analyses

The usefulness of indicators in detecting ecosystem change depends on three main criteria: the availability of data to estimate the indicator (measurability), the ability to detect change in an ecosystem (sensitivity), and the ability to link the said change in an indicator as a response to a known intervention or pressure (specificity). Here, we specifically examine the third aspect of indicator change, with an emphasis on multiple methods to explore the \"relativity\" of major ecosystem drivers. We use a suite of multivariate methods to explore the relationships between a pre-established set of fisheries-orientated ecosystem status indicators and the key drivers for those ecosystems (particularly emphasizing proxy indicators for fishing and the environment). The results show the relative importance among fishing and environmental factors, which differed notably across the major types of ecosystems. Yet, they also demonstrated common patterns in which most ecosystems, and indicators of ecosystem dynamics are largely driven by fisheries (landings) or human (human development index) factors, and secondarily by environmental drivers (e.g. AMO, PDO, SST). How one might utilize this empirical evidence in future efforts for ecosystem approaches to fisheries is discussed, highlighting the need to manage fisheries in the context of environmental and other human (e.g. economic) drivers.

Keywords: Dinoflagellates · Infectivity · Parvilucifera sinerae · Parasite · Small-scale turbulence · Sporangia · Numerical model

Small-scale turbulence and parasite infection are 2 important factors that govern the dynamics and fate of phytoplankton populations. We experimentally investigated the influence of turbulent mixing on the infectivity of the parasite Parvilucifera sinerae to dinoflagellates. Natural phytoplankton communities were collected during 3 stages of a bloom event in Arenys de Mar Harbour (NW Mediterranean). The 15 to 60 µm size fraction was used as the inoculum and distributed into spherical flasks. Half of the recipients were exposed to turbulence while the rest were kept still. In the experiments, the dinoflagellate assemblage was mainly composed of Prorocentrum micans, Scrippsiella trochoidea and Alexandrium minutum. We observed a collapse of A. minutum and S. trochoidea populations in the unshaken flasks, which coincided with an increase in parasite infectivity. After a short exposure to turbulence, the development of the dinoflagellate populations slowed down and stabilised as expected. In the shaken treatments, the infectivity was lower and the decay in the host cells numbers was delayed compared to the still treatments. The degree of interference of the turbulence with infectivity varied among the experiments, due to differences in cell abundances and possibly their physiological state. Results from a numerical model suggest that turbulence could lead to a 25 to 30% decrease in the maximum infection rate, which could be due to host population dispersion and/or reduced host–parasite contact times. Turbulence may thus be effective in delaying the initial infection, but not in preventing it.

Keywords: Spain; Catalunya; Alfacs Bay; Mediterranean Sea; Dissolved organic phosphorus; Resuspended sediments; Ecological modeling; Phytoplankton; Limiting factors

The effect of Dissolved Organic Phosphorus (DOP) availability and nutrient limitation of phytoplankton growth in an estuarine bay (Alfacs Bay, NW Mediterranean) have been studied by means of a zero-dimensional ecological model including nitrogen, phosphorus (organic and inorganic), two groups of phytoplankton (diatoms and flagellates), one group of zooplankton, and detritus. Simulations with and without DOP as an extra source of phosphorus for phytoplankton growth suggest that DOP plays an important role in the dynamics of the Alfacs Bay ecosystem. DOP is indeed necessary to simulate the observed draw-down of nitrate and build up of phytoplankton biomass. Two non-exclusive mechanisms allowing DOP availability for phytoplankton are possible: direct uptake, or remineralization to Dissolved Inorganic Phosphorus. Including both gives a better agreement with the observations. Inclusion of DOP in the model leads to predominance of phosphorus limitation of phytoplankton growth in fall and winter, and of nitrogen limitation in late spring and summer. Simulations with and without sediment resuspension suggest that this process does not significantly affect the nutrient budget in the bay.

Keywords: Nototheniidae - Otolith sagitta - Ecomorphology - Phylogenetic inertia - Shape analyses

A quantitative ecomorphological study was carried out on the sagitta otoliths of Antarctic and Subantarctic nototheniids, a particularly interesting family due to its fast adaptive radiation into different life strategies. We analyzed the otolith shape and size of 18 nototheniids to test the relationship between phylogeny, otolith characters and trophic niche. Relative size (area, length, width, perimeter and weight) and shape (biometric warp analysis based on homologous and pseudo-homologous landmarks) measurements were compared with phylogenic, habitat dwelling and food composition analyses. The results of the multivariate analysis of these factors indicate that there is a weak relationship between otolith shape of nototheniids and phylogeny; however, there is a clear correspondence between relative otolith size and shape and their trophic niche. The most benthic feeders of the family had the largest sagittae in relation to body size, and pelagic species had smaller and rounder shaped sagittae than benthic species. Consequently, in ecomorphological studies, it is useful to analyze the size and shape of sagittae. The discoidal shape of pelagic species, such as Pleuragrama antracticum, can be considered as a paedomorphic characteristic, converging to the juvenile sagittae of many species, which exhibit round sagittae that become elongated as they grow.

Keywords: Mexel®432; Mytilus galloprovincialis; Sodium hypochlorite; Stress parameters

The sublethal effects of two antifoulants currently used in power plant cooling systems were assessed in the common mussel Mytilus galloprovincialis. The concentrations of sodium hypochlorite (NaClO) and an alkyl amine surfactant (Mexel®432) assayed, were within the range of those currently discharged by power plants into receiving waters. Enzymatic activities and oxidative stress responses were measured in digestive gland and gill of mussels after 1, 3, 7 and 14 days of exposure, as well as histopathology in gill tissue. Both antifoulants caused a pathological response in gills and the activities of the enzymes glutathione S-transferase, catalase, acetylcholinesterase and the lipid peroxidation levels were also affected. Exposure to NaClO caused a greater toxicological response than Mexel®432. In both treatments, gills appeared to be the most affected tissue, although Mexel®432 also significantly affected digestive gland parameters.

Keywords: Antioxidant responses; Osmoregulation; Sodium hypochlorite; Solea senegalensis; Stress biomarkers

The time–course stress responses (0, 1, 2, and 7 d) was assessed in plasmatic, branchial and renal parameters of juveniles Solea senegalensis exposed to different concentrations of the antifouling sodium hypochlorite (0.1, 0.2, and 0.5 mg L−1). These stress responses were only assessed for the total length of exposure (7 d) at the lowest NaClO concentration due to the high toxicity of this chemical. In addition, the xenobiotic metabolism responses were evaluated by means of enzymatic activities of ethoxyresorufin O-deethylase (EROD), glutathione S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPX), catalase (CAT), and carboxylesterase (CbE) in liver; as well as GST, GPX, CAT and acetylcholinesterase (AChE) in gill. Oxidative stress damage due to sodium hypochlorite exposure was measured by lipid peroxidation levels in liver and gill. Concentrations of 0.2 and 0.5 mg L−1 produced lethal effects after 1 d and 2 h of exposure, respectively. After 1 d of exposure to sublethal concentration of sodium hypochlorite (0.1 mg L−1) osmoregulatory (osmolality and chloride) and stress (cortisol, glucose and lactate) plasmatic parameters were enhanced to respect at control fish. However after 3 or 7 d these parameters returned to control values. No effects were observed on plasma protein and triglyceride levels or on gill and kidney Na+/K+-ATPase activities. Diverse gill pathologies such as hypertrophy, lamellar fusion and an increase in goblet cell number and size were observed after 7 d of exposure. Most biochemical parameters related to xenobiotic metabolism and oxidative stress were also significantly affected which suggests that seawater affected by sodium hypochlorite discharges from power plants, is able to alter the fish xenobiotic metabolism and generate oxidative stress.

Keywords: Histopathology; Mexel®432; Osmoregulation; Oxidative stress; S. senegalensis; Xenobiotic metabolism

Mexel®432 is an anionic surfactant used as biocide in the cooling water system of power plants for biofouling reduction. Refrigeration waters from power plants do not usually follow, prior to their discharge to sea, any treatment aimed to eliminate biocides and this can have negative consequences on the aquatic fauna nearby. The effects of different concentrations of the antifoulant Mexel®432 (0.5, 1 and 2 mg L−1) on osmoregulation (osmolality and Na+/K+-ATPase activity) and stress parameters (cortisol, glucose, and lactate) were assessed in juveniles of the flatfish Solea senegalensis. Gill histopathology and alterations due to oxidative stress (increased lipid peroxidation, LPO, levels) at branchial and hepatic levels were also considered. Other parameters tested were the antioxidant enzymes (catalase, CAT; glutathione peroxidase, GPX; and glutathione reductase, GR), xenobiotic metabolism defenses involved in detoxification (carboxylesterase, CbE; 7-ethoxyresorufin O-deethylase, EROD; and glutathione S-transferase, GST) and the neurotransmitter acetylcholinesterase (AChE) activity. Significant variations in osmoregulatory parameters, histological lesions and decreased branchial Na+/K+-ATPase activity were observed in exposed fish. Other gill biomarkers presented little or no significant variations in relation to controls. In contrast, hepatic parameters, such as CAT activity, were inhibited while EROD activity was initially elevated but after longer exposures it recovered basal values. These results suggested that under our experimental protocol exists toxic associated to Mexel®432 exposures.

Keywords: phytoplankton; dissolved organic carbon; Ria de Vigo

We studied the importance of dissolved primary production in a coastal, productive ecosystem in relation to phytoplankton biomass, community structure and productivity. The photosynthetic production of dissolved organic carbon (DOCp) and particulate organic carbon was determined in mesocosm experiments during four contrasting oceanographic periods in the Ría de Vigo (NW Iberian Peninsula). We also determined the size-fractionated chlorophyll a concentration and primary production, phytoplankton taxonomic composition and bacterial production. Phytoplankton biomass was dominated by the >20 µm size fraction (mostly diatoms), except in winter, when the 2–20 and <2 µm size fractions (flagellates and picophytoplankton) increased in importance. The percentage of extracellular release (PER) had an average value of 19% and was independent of oceanographic period, phytoplankton biomass and production, taxonomic composition and size structure. During phytoplankton blooms, PER increased significantly from 14% in the exponential growth phase to 23% in the senescent phase. Bacterial carbon demand and DOCp were uncoupled, suggesting that other processes in addition to photosynthate exudation contribute most of the labile carbon to fuel bacterial metabolism. Dissolved primary production remains an important process in coastal phytoplankton assemblages throughout the year, irrespective of size-structure and community composition, but attaining higher significance during the decaying phase of blooms.

Dormancy is a general term describing a state whereby metabolism and normal progression of life activities and development are dramatically reduced or brought to a halt. Dormancy facilitates the survival of organisms during environmental conditions that cannot support the regular course of life. Many organisms have evolved the capacity to enter dormancy and exit from it. Common pathways have been identified in several forms, in spite of the diversity and complexity in the survival strategies during dormancy in organisms displaying it. Revealing the mode of regulation of these pathways and the occurrence of other functions associated with dormancy are some of the great future challenges. This may open the way for revealing how cells, tissues or entire organisms can be made dormant or be revived effectively and lead to preserving cells, tissues and organs at ambient temperatures. These aspirations motivated the publication of this book.

Keywords: (10.5–5.5 °W/33.5–37.5 °N); Inverse model; Upper ocean; Expandable bathythermograph

We test the skill of a polynomial fit to reproduce the upper ocean (down to 750 m) salinity in the eastern North Atlantic (from the Canary Islands to the Iberian Peninsula, approximately 12° × 12°) as a function of temperature and depth. A historical database, constructed by merging several regional datasets, is used. An ANOVA test is performed to determine the optimum degree of temperature and depth in the polynomial fit. The polynomial coefficients are estimated by solving an inverse model where we control the size of both coefficients and residuals. We divide the basin in 21 zones (2° × 2°) and four regions (each comprising several zones), and run the inversion for the whole basin, as well as for each individual region and zone. This allows us to assess the sensitivity of the model to changes in the spatial domain, and to investigate the spatial variability of the polynomial coefficients. Regions are defined by applying a cluster analysis to objectively group those zones with similar oceanographic properties. The seasonality of the coefficients is addressed with data from the whole basin and individual regions. We find that, for either the whole basin or individual regions, seasonal coefficients predict salinity more accurately than annual ones, but annual coefficients per zone yet provide the best results. The depth-averaged error estimating salinity is less than 0.086 psu.

Two 9-yr current-meter and salinity records, together with climatological data, reveal marked seasonal variability of the intermediate flow at a key location in the Canary Basin. The region is characterized by a summer (July–September) and early fall (October) northward progression of Antarctic Intermediate Water followed by a fall (November–December) intense flow reversal of Mediterranean Water. A Sverdrup-type model confirms that these movements are associated with stretching or shrinking of the intermediate water strata.

Keywords: Gulf of California · Trawling · Bycatch · Closed season · Population structure

From April to December 2007, experimental trawls (n = 44, 4 to 22 m depth) were made off the mouth of the Rio Baluarte ecosystem (MRB) and compared to experimental trawls (n = 54, 7 to 40 m) in the adjacent offshore region (AOR) from 2002 to 2007. For both ecosystems, a total of 143 species belonging to 5 phyla were collected. Fishes comprised ca. 80% of the bycatch biomass, while molluscs and echinoderms contributed <20% bycatch. Eight species accounted for 50% of the numerical abundance: the crab Portunus asper (11%), the Panama grunt Pomadasys panamensis (8%), the curvina Stellifer ericymba (7%), the comb sand star Astropecten armatus (6%), the fishes Orthopristis chalceus (6%) and Larimus effulgens (4%), and the crabs Callinectes arcuatus (4%) and Hepatus kossmani (3%). Species with a high or medium survival rate with respect to trawling activity were well represented in the samples, e.g. the crabs C. arcuatus, H. kossmani, and Euphilax robustus, the hermit crab Petrochirus californiensis, and the sea star Luidia brevispina. For the MRB and AOR, the estimated mean biomass was 2.08 and 0.72 t km–2, respectively. The population of the blue shrimp Litopenaeus stylirostris and white shrimp L. vannamei was composed of recruits, juveniles, spawners, and old individuals, whereas for grunts it was composed of recruits and juveniles, but rarely old individuals. The high diversity, population structure, and productivity of the studied fauna has positive effects, such as enabling the recruitment for coastal marine fisheries. This is an important reason to protect the river mouth and the adjacent shallow waters.

Nonlinear phenomena are essential ingredients in many oceanic and atmospheric processes, and successful understanding of them benefits from multidisciplinary collaboration between oceanographers, meteorologists, physicists and mathematicians. The present Special Issue on \"Nonlinear Processes in Oceanic and Atmospheric Flows\" contains selected contributions from attendants to the workshop which, in the above spirit, was held in Castro Urdiales, Spain, in July 2008. Here we summarize the Special Issue contributions, which include papers on the characterization of ocean transport in the Lagrangian and in the Eulerian frameworks, generation and variability of jets and waves, interactions of fluid flow with plankton dynamics or heavy drops, scaling in meteorological fields, and statistical properties of El Niño Southern Oscillation.

Keywords: aquatic ecosystems; bacterial community composition; bacterial physiology; lysogeny; MAR-FISH; temperate phages

Previous studies indicate that lysogeny is preponderant when environmental conditions are challenging for the bacterial communities and when their metabolism is reduced. Furthermore, it appears that lysogeny is more frequent within certain bacterial phylogenetic groups. In this comparative study from 10 freshwater reservoirs and 10 coastal lagoons, we aim to disentangle the influence of these different factors. In eight reservoirs and four lagoons, lysogeny was detected by induction assays with mitomycin C, and induction significantly modified the bacterial community composition (BCC), whereas community composition remained constant in ecosystems in which lysogeny was not observed. Among the phylogenetic groups studied, the most abundant ones were Bacteroidetes and α-proteobacteria in lagoons, and β-proteobacteria and Bacteroidetes in reservoirs. These dominant groups comprised the highest proportions of inducible lysogens. In order to unravel the effects of bacterial metabolism from phylogeny on lysogeny, we measured bacterial community physiology and the specific activities of selected phylogenetic groups. The proportion of inducible lysogens within the α- and the β-proteobacteria decreased with increasing group-specific metabolism in lagoons and reservoirs, respectively. In contrast, this relationship was not observed for the other lysogen-containing groups. Hence, both host physiology and phylogeny are critical for the establishment of lysogeny. This study illustrates the importance of lysogeny among the most abundant phylogenetic groups, and further suggests its strong structuring impact on BCC.

CO2-driven compromises to marine life were examined along the Chilean sector of the Humboldt Current System, a particularly vulnerable hypoxic and upwelling area, applying the Respiration index (RI = log10pO2_pCO2) and the pH-dependent aragonite sat- 5 uration (Ω) to delineate the water masses where aerobic and calcifying organisms are stressed. There was a remarkable negative relationship between oxygen concentration and pH or pCO2 in the studied area, with the subsurface hypoxic Equatorial SubsurfaceWaters extending from 100m to about 300 m depth and supporting elevated pCO2 values. The RI reached a minimum at about 200 m depth and decreased towards the 10 Equator. Increased pCO2 in the hypoxic water layer reduced the RI values by as much as 0.59 RI units, with the upper water layer that presents conditions suitable for aerobic life (RI>0.7) declining by half between 42◦ S and 28◦ S. The intermediate waters hardly reached those stations closer to the equator so that the increased pCO2 lowered pH and the saturation of aragonite. A significant fraction of the water column along the 15 Chilean sector of the Humboldt Current System suffers from CO2–driven compromises to biota, including waters corrosive to calcifying organisms, stress to aerobic organisms or both. The habitat free of CO2-driven stresses was restricted to the upper mixed layer and to small water parcels at about 1000 m depth. pCO2 acts as a hinge connecting respiratory and calcification challenges expected to increase in the future, resulting in 20 a spread of the challenges to aerobic organisms

Keywords: Kisspeptin; Kiss1r; Kiss-1 receptor; gpr54; Puberty; Atlantic halibut

Kisspeptin and its receptor, Kiss1r, play an essential role in the control of the onset of puberty in vertebrates. We characterized the cDNA and genomic DNA encoding Kiss1r in Atlantic halibut (Hippoglossus hippoglossus). The 1146 bp open reading frame predicts a 381 amino acid protein with high homology to the Kiss1r-2 of other teleost fish. Phylogenetic analysis of Kiss1r sequences suggests that the mammalian Kiss1r-1 form arose by way of a gene duplication prior to the emergence of amphibians. Synteny analysis demonstrated the highly conserved nature of the Kiss1r-2 region in teleosts, suggesting that flanking regulatory sequences are also likely to be conserved. Bioinformatic analysis identified six conserved regions in piscine Kiss1r-2 upstream sequences, providing potential targets for future in-depth investigation of Kiss1r-2 regulation. Kiss1r-2 expression in the brain increased coinciding with the onset of puberty. Expression levels in the gonads were two orders of magnitude lower than those of the brain, a characteristic apparently conserved in other fishes, and expression in gonads was only detected in immature fish.

Keywords: Antarctic krill · Seasonal condition · Overwintering

We investigated physiological parameters (elemental and biochemical composition, metabolic rates, feeding activity and growth) of adult Antarctic krill in the Lazarev Sea in late spring (December), mid autumn (April) and mid winter (July and August) to evaluate proposed hypotheses of overwintering mechanisms. Our major observations are: (1) respiration rates were reduced by 30 to 50% in autumn and winter, compared to values in late spring; (2) feeding activity was reduced by 80 to 86% in autumn and winter, compared to late spring, at similar food concentrations; (3) feeding was omnivorous during winter; (4) with each moult, krill grew by 0.5 to 3.8% in length; (5) body lipids and, to a small extent, body proteins were consumed during winter. Adult Euphausia superba thus adopt metabolic slowdown and omnivorous feeding activity at low rates to survive the winter season in the Lazarev Sea. By mid autumn, metabolic activity is reduced, most likely being influenced by the Antarctic light regime, which is accompanied by a reduction in feeding activity and growth. Although at a low level, the feeding activity during winter seems to provide an important energy input.

Keywords: climate change; ecosystem services; biotic interactions; biodiversity; ecological networks; resilience

Climate change is real. The wrangling debates are over, and we now need to move onto a predictive ecology that will allow managers of landscapes and policy makers to adapt to the likely changes in biodiversity over the coming decades. There is ample evidence that ecological responses are already occurring at the individual species (population) level. The challenge is how to synthesize the growing list of such observations with a coherent body of theory that will enable us to predict where and when changes will occur, what the consequences might be for the conservation and sustainable use of biodiversity and what we might do practically in order to maintain those systems in as good condition as possible. It is thus necessary to investigate the effects of climate change at the ecosystem level and to consider novel emergent ecosystems composed of new species assemblages arising from differential rates of range shifts of species. Here, we present current knowledge on the effects of climate change on biotic interactions and ecosystem services supply, and summarize the papers included in this volume. We discuss how resilient ecosystems are in the face of the multiple components that characterize climate change, and suggest which current ecological theories may be used as a starting point to predict ecosystem-level effects of climate change.

Los fenómenos biológicos se suceden con gran rapidez en los medios acuáticos y, particularmente, en el medio marino. Se denomina bioincrustación (biofouling) a un conjunto de procesos biológicos relacionados con las primeras etapas de colonización de un sustrato sumergido. En el mar, la celeridad con que se produce dicha colonización es notable: en tan sólo unos días aparecen diferentes incrustaciones recubriendo la superficie de un sustrato que inicialmente se había sumergido impoluto. El proceso plantea desde hace años problemas serios a la navegación, pues la bioincrustación origina una capa que se extiende sobre al casco de los barcos. La capa aumenta el rozamiento de las embarcaciones y, como consecuencia, reduce su velocidad y provoca un mayor consumo de combustible. La colonización del sustrato empieza por bacterias, de mínimas exigencias nutritivas, que constituyen las biopelículas bacterianas, complejas estructuras formadas por los propios microorganismos embebidos en sustancias que ellos mismos segregan. Transcurrida una semana, diversas especies medran en la superficie de este sustrato inicial y acaban creando una primera capa de incrustación; distinguimos en ese conglomerado diversas especies de diatomeas bentónicas, serpúlidos y briozoos. La colonización sigue un proceso de sucesión que da como resultado unas comunidades cada vez más complejas con el tiempo. De no limpiarlas periódicamente, las embarcaciones sufren una degradación progresiva.

Keywords: anchovy, fish larvae, larval development, plankton availability, sardine, selectivity, trophic ecology.

The feeding ecology of the larvae of the two most important small pelagic species in the western Mediterranean, anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus), is investigated. Samples were collected in early summer (anchovy) and autumn (sardine). Composition of the diet and prey selectivity were compared over the course of ontogeny in anchovy (2.7–14.5 mm standard length, SL) and sardine (5.5–15.8 mm SL) larvae. Anchovy larvae begin feeding on prey items .150 mm at smaller sizes than sardine larvae, and the diets of both species are based mainly on copepod nauplii and postnauplii. Seasonal differences in the composition of the plankton influenced the contributions of prey types to the diets of the two species, e.g. the cladoceran Evadne spp. in anchovy and the tintinnid Codonellopsis sp. in sardine. Although copepod eggs are generally present in the diets of larval clupeoids, they were not major components of the diets of the species considered here. Despite morphological similarity, selection patterns were different between the species and changed through ontogeny.

El seguimiento de las pardelas cenicientas de una colonia del suroeste de la isla de Gran Canaria ha revelado interesantes detalles sobre las estrategias de alimentación de esta ave marina pelágica. La cercana costa africana, una de las zonas de mayor productividad biológica del océano Atlántico, es vital para esta especie, que se ve influida a la hora de buscar comida por factores como el viento oceánico o las tareas reproductoras.

The availability of food resources has been suggested as a major factor in the substantial increase in reproductive output, survival, recruitment and, ultimately, population growth rates in most organisms. In fact, the artificial increase in food availability resulting from human activities has been suggested as a factor in the substantial increase in population size of several seabirds in recent decades. In the present study, our primary aim was to estimate the importance of the main natural prey and two alternative feeding resources, fishery discards and the invasive American crayfish Procambarus clarkii, for an opportunistic seabird, the Audouin’s gull Larus audouinii. We also assessed the influence of age and sex in the use of those three types of food. For this purpose, we compared the analyses of δ15N and δ13C in blood of male and female adults of known age and chicks with those in their potential prey. Our results reveal sex-related and age-related differences in the consumption of fish discards, small pelagic fish and American crayfish. Differences in the diet of males and females and also between adults and chicks could be related to different nutritional requirements. Age differences were probably related to their different foraging proficiency and the tendency of young breeders to opportunistically exploit anthropogenically derived food. This study illustrates the importance of considering the age and sex of individuals to obtain feasible dietary information and to understand how the exploitation of food of human origin could affect population growth.

The morphological changes caused by storm events in two Barcelona beaches were recorded using video monitoring techniques during the period 2001–2006. Changes in shoreline position and configuration and submerged bar position and shape were analyzed during the 25 major storm events that occurred during the study period. Beach responses to storms were grouped into three categories: shoreline advance or retreat (including rotation), sandbar migration and/or configuration change (linear or crescentic shape) and formation of megacusps. This work provides examples of the differential adaptation of both beaches to the same storm and of some unexpected morphological responses of both beaches. The response of the beach to storm events is not straightforward because wave conditions are not the only relevant parameter to be considered. In particular, in such embayed beaches it is crucial to take into account their specific morphodynamic configuration prior to the storm.

Keywords: Multimarker approach; Biomonitoring; Micronuclei; Aryl hydrocarbon receptor; Recombinant yeast assay; Quantitative real-time PCR

Pollution in riverine systems, along with its biological effects, may propagate downstream even at considerable distances. We analyzed the organochlorine compound (OC) pollution in a section of the low Ebro River (Northeast Spain) downstream a long-operating chlor-alkali plant. Maximal levels of OCs and of their associated dioxin-like biological activity occurred in residue samples from the plant, and persisted in river sediments some 40 km downstream (Xerta site). Biological analysis at multiple organization levels in local carp (Cyprinus carpio, EROD, Cyp1A mRNA expression in the liver, hepatosomatic index, condition factor, and micronuclei index in peripheral blood) showed a similar pattern, with a maximal impact in Ascó, few kilometers downstream the plant, and a clear reduction at Xerta. This combination of chemical, molecular, cellular and physiological data allowed the precise assessment of the negative impact of the chlor-alkali plant on the quality of river sediments and on fish, and suggests that sediments may be a reservoir for toxic substances even in dynamic environments like rivers.

Keywords: diversity • fish larvae • horizontal distribution • larval transport • temporal variability • vertical distribution • zooplankton

In the northwestern Mediterranean, most fish species reproduce in early summer and fewer in the autumn mixing period. This study analyses and compares larval fish assemblages (LFA) in both seasons, and is the first attempt to characterize LFA structure for the autumn period. We analyze horizontal and vertical distribution of fish larvae and the micro- and mesozooplankton biomass and abundance of the main zooplankton groups. The oceanographic situation was analyzed through the study of data from CTD, Nν-Shuttle and ADCP surveys. LFA were determined by ordination analyses based on larval abundance, and the relationships between larval assemblages and environmental variables were investigated through canonical correspondence analysis. The importance of some hydrographic variables (temperature, salinity and stability of the water column), current fields (along-shelf and across-shelf transport) and the abundance of zooplankton are discussed as important factors shaping the structure of larval assemblages. In early summer, LFA were mainly structured by a combination of bathymetry and trophic components, although sea surface temperature also played a role in shaping the horizontal larval distributions. In autumn, trophic variables were the main factors influencing the shelf-dwelling species assemblage. Larvae of oceanic species, on the other hand, were not related to trophic variables but were more affected by current fields.

Keywords: Medusozoa; DNA Barcoding; mtCOI; Molecular identification; Gelatinous zooplankton

The Medusozoa are a clade within the Cnidaria comprising the classes Hydrozoa, Scyphozoa, and Cubozoa. Identification of medusozoan species is challenging, even for taxonomic experts, due to their fragile forms and complex, morphologically-distinct life history stages. In this study 231 sequences for a portion of the mitochondrial Cytochrome Oxidase I (mtCOI) gene were obtained from 95 species of Medusozoans including; 84 hydrozoans (61 siphonophores, eight anthomedusae, four leptomedusae, seven trachymedusae, and four narcomedusae), 10 scyphozoans (three coronatae, four semaeostomae, two rhizostomae, and one stauromedusae), and one cubozoan. This region of mtCOI has been used as a DNA barcode (i.e., a molecular character for species recognition and discrimination) for a diverse array of taxa, including some Cnidaria. Kimura 2-parameter (K2P) genetic distances between sequence variants within species ranged from 0 to 0.057 (mean 0.013). Within the 13 genera for which multiple species were available, K2P distance between congeneric species ranged from 0.056 to 0.381. A cluster diagram generated by Neighbor Joining (NJ) using K2P distances reliably clustered all barcodes of the same species with ≥99% bootstrap support, ensuring accurate identification of species. Intra- and inter-specific variation of the mtCOI gene for the Medusozoa are appropriate for this gene to be used as a DNA barcode for species-level identification, but not for phylogenetic analysis or taxonomic classification of unknown sequences at higher taxonomic levels. This study provides a set of molecular tools that can be used to address questions of speciation, biodiversity, life-history, and population boundaries in the Medusozoa.

Keywords: Zooplankton; Siphonophores; Atlantic Ocean; Sargasso Sea

We report a collection of the siphonophore Halistemma cupulifera, collected at 20 meters depth during a night SCUBA dive in the Sargasso Sea. One of its stomachs (gastrozooids) contained a leptocephalus larva of the eel Ariosoma sp. folded in thirds to fit, but 8.3 cm in length fully extended. This finding shows that in situ observations can reveal previously unknown trophic interactions that may be significant in a changing world ocean where gelatinous organisms seem to increase at the expense of fish.

Keywords: Palinura, RRS Discovery, Scyllaridae, Linuparus, Justitia

Four rare palinurid phyllosoma larvae, one mid-stage and three final stage, were found among the unclassified collections in the Crustacea Section, Natural History Museum, London. Detailed morphological analysis of the larvaeindicated that they belong to several Palinustus species given the presence of incipient blunt-horns, length of antennula, length ratio of segments of antennular peduncle, distribution of pereiopod spines, and shape of uropods and telson. Moreover, the size of the final-stage larvae agrees with that expected given the size of the recently described puerulus stage of Palinustus mossambicus. This constitutes the first description of a complete phyllosoma assigned to Palinustus species. The phyllosoma described in the present study include the largest Palinuridae larva ever found.

Keywords: conservation, effective size, overfishing, Palinuridae, genetics

Most fisheries involving spiny lobsters of the genus Palinurus have been overexploited during the last decades, so there is a raising concern about management decisions for these valuable resources. A total of 13 microsatellite DNA loci recently developed in Palinurus elephas were assayed in order to assess genetic diversity levels in every known species of the genus. Microsatellite markers gave amplifications and showed polymorphism in all species, with gene diversity values varying from 0.650 ± 0.077 SD (Palinurus barbarae) to 0.792 ± 0.051 SD (Palinurus elephas). Most importantly, when depth distribution was taken into account, shallower water species consistently showed larger historical effective population sizes than their deeper-water counterparts. This could explain why deeper-water species are more sensitive to overfishing, and would indicate that overexploitation may have a larger impact on their longterm genetic diversity.

Keywords: Otolith; Automatic Taxon Identification; Wavelets; Database

Automated Taxon Identification (ATI) systems that use a database to identify species or anatomical structures of species from different taxonomical groups have recently been developed. However, few of these works have been applied to marine organisms. In this paper we develop an ATI system for identifying Actynopterigian species from their otolith contour; this is important information for the palaeontological, ictiological and ecological sciences, especially in food web studies. The AFORO website comprises the first web-based automated species identification system based exclusively on otolith shape outline. Species are identified iteratively based on a multiscale representation of the otolith contour. The ATI system is very easy to use as it only requires uploading a suitably oriented otolith image on a black background. Two tests were carried out with a database of 1480 images of left sacullar otoliths (sagittae) from 420 species. The first test analysed 50 different otoliths, 10 per species, from 5 different species. The second test identified 50 otoliths, each from a different species. The two tests obtained similar results (percentage of correct identifications): 72% of specimens were correctly identified at species level, and the percentage increased to 90% at genus level and reached 94% at family level. The best results are obtained for species which have an otolith contour with a very specific morphology, such as the mackerel Scomber colias, and the less efficient results for species with common shaped otoliths with unclear specific characteristics, such as the Mediterranean horse-mackerel Trachurus mediterraneus, or species with large morphological variability between individuals, such as Lophius budegassa or Synodus saurus.

Settling particles were collected using sediment traps deployed along three transects in the Lacaze-Duthiers and Cap de Creus canyons and the adjacent southern open slope from October 2005 to October 2006. The settling material was analyzed to obtain total mass fluxes and main constituent contents (organic matter, opal, calcium carbonate, and siliciclastics). Cascades of dense shelf water from the continental shelf edge to the lower continental slope occurred from January to March 2006. They were traced through strong negative near-bottom temperature anomalies and increased current speeds, and generated two intense pulses of mass fluxes in January and March 2006. This oceanographic phenomenon appeared as the major physical forcing of settling particles at almost all stations, and caused both high seasonal variability in mass fluxes and important qualitative changes in settling material. Fluxes during the dense shelf water cascading (DSWC) event ranged from 90.1 g m−2 d−1 at the middle Cap de Creus canyon (1000 m) to 3.2 g m−2 d−1 at the canyon mouth (1900 m). Fractions of organic matter, opal and calcium carbonate components increased seaward, thus diminishing the siliciclastic fraction. Temporal variability of the major components was larger in the canyon mouth and open slope sites, due to the mixed impact of dense shelf water cascading processes and the pelagic biological production. Results indicate that the cascading event remobilized and homogenized large amounts of material down canyon and southwardly along the continental slope contributing to a better understanding of the off-shelf particle transport and the internal dynamics of DSWC events.

Keywords: Food limitation · Larval growth · Polydora ciliata · Larvae

Food limitation in larval growth of the spionid polychaete Polydora ciliata was examined in a typical eutrophic estuary, Isefjord, in Denmark. In the field, food availability and the energetic requirements of the P. ciliata larval population were measured during 2 different periods in 2004 and 2007 that together cover the productive part of the year for plankton. In the laboratory, specific growth rates (µ) of larvae reared on natural food suspensions (~0.10 d–1) were always lower than those of larvae reared on phytoplankton-enriched food suspensions (100% retention efficiency for Rhodomonas salina; ~0.21 d–1). Total meroplankton biomass (average: 3.72 µg C l–1, range: 0.11 to 26.05 µg C l–1) was frequently similar to or exceeded that of holoplankton (average: 5.70 µg C l–1, range: 0.08 to 29.89 µg C l–1), suggesting a trophic significance of meroplankton in the estuary. P. ciliata was commonly the dominant meroplanktonic larvae (average: 0.5 µg C l–1, range: 0.03 to 2.51 µg C l–1). The available food in the optimal prey size fraction (2004, average: <20 µm; range: 99 to 274 µg C l–1; 2007, average: 7 to 18 µm; estimated carbon demand: 119 µg C l–1; range: 19 to 474 µg C l–1) seemed to be sufficient to cover the energetic carbon requirements of the population throughout the study (0.09 to 3.15 µg C l–1 d–1), but insufficient to attain the maximum specific growth rates reported in previous laboratory experiments. This suggests that P. ciliata larvae probably exhibit a low feeding efficiency and their maximum specific growth rates are consequently attained at food concentrations even higher than those found in this eutrophic environment.

Keywords: Transparent exopolymer particles · TEP production · Phytoplankton · Particulate organic carbon · POC · Turbulence · Nutrients · Mesocosms

The production of transparent exopolymer particles (TEP) in response to several environmental variables was studied in 2 mesocosm experiments. The first (Expt 1) examined a gradient of 4 nutrient levels; the second (Expt 2) examined different conditions of silicate availability and zooplankton presence. Tanks were separated in 2 series, one subjected to turbulence and the other not influenced by turbulence. In tanks with nutrient addition, TEP were rapidly formed, with net apparent production rates closely linked to chl a growth rates, suggesting that phytoplankton cells were actively exuding TEP precursors. High nutrient availability increased the absolute concentration of TEP; however, the relative quantity of TEP produced was found to be lower, as TEP concentration per unit of phytoplankton biomass was inversely related to the initial nitrate dose. In Expt 1, an increase in TEP volume (3 to 48 μm equivalent spherical diameter) with nutrient dose was observed; in Expt 2, both silicate addition and turbulence enhanced TEP production and favored aggregation to larger TEP (>48 μm). The presence of zooplankton lowered TEP concentration and changed the size distribution of TEP, presumably by grazing on TEP or phytoplankton. For lower nutrient concentrations, the ratio of particulate organic carbon (POC) to particulate organic nitrogen (PON) followed the Redfield ratio. At higher nutrient conditions, when nutrients were exhausted during the post-bloom, a decoupling of carbon and nitrogen dynamics occurred and was correlated to TEP formation, with a large flow of carbon channeled toward the TEP pool in turbulent tanks. TEP accounted for an increase in POC concentration of 50% in high-nutrient and turbulent conditions. The study of TEP dynamics is crucial to understanding the biogeochemical response of the aquatic system to forcing variables such as nutrient availability and turbulence intensity.

The anthropogenic rise in atmospheric CO2 is driving fundamental and unprecedented changes in the chemistry of the oceans. This has led to changes in the physiology of a wide variety of marine organisms and, consequently, the ecology of the ocean. This review explores recent advances in our understanding of ocean acidification with a particular emphasis on past changes to ocean chemistry and what they can tell us about present and future changes. We argue that ocean conditions are already more extreme than those experienced by marine organisms and ecosystems for millions of years, emphasising the urgent need to adopt policies that drastically reduce CO2 emissions.

Keywords: HAB species, Mediterranean Sea, PCR, Ribosomal genes, Resting stages, Sediments

A PCR-based assay was developed and applied to sediment and sediment trap samples for the detection of different cysts belonging to dinoflagellates and raphidophytes in European coastal areas. Oligonucleotide primers were designed based on the ITS-5.8S and LSU ribosomal gene sequences. The specificity and sensitivity of the PCR assay were assessed using genomic DNA from clonal cultures, plasmid copy number of cloned target sequences, as well as from sediment samples. Qualitative PCR determinations of different cysts in sediment and sediment trap samples were compared to taxonomic examinations by light microscopy. This molecular methodology permitted a fast and specific detection of target cysts in sediment samples. We also detected dinoflagellate and raphidophyte cysts at concentrations not detectable by microscopic methods or that are difficult to identify. The results given by molecular and microscopic methods were comparable. However, higher values of positive detection for target cysts were obtained by PCR than with microscopy. Some taxa were detected in 100% of the samples using PCR, while others were only found in 10% of the samples. The data obtained in this study showed that the PCR-based method is a valid tool for cyst identification in marine sediments.

Rotational motions in homogeneous anisotropic elastic media are studied under the assumption of plane wave propagation. The main goal is to investigate the influences of anisotropy in the behavior of the rotational wavefield. The focus is on P-waves that theoretically do not generate rotational motion in isotropic media. By using the Kelvin–Christoffel equation, expressions are obtained of the rotational motions of body waves as a function of the propagation direction and the coefficients of the elastic modulus matrix. As a result, the amplitudes of the rotation rates and their radiation patterns are quantified and it is concluded that (1) for strong local earthquakes and typical reservoir situations quasi P-rotation rates induced by anisotropy are significant, recordable, and can be used for inverse problems; and (2) for teleseismic wavefields, anisotropic effects are unlikely to be responsible for the observed rotational energy in the P coda

Keywords: Bacterial diversity · Pyrosequencing · Blanes Bay Microbial Observatory

Due to analytical limitations, patterns of richness and evenness of microbes are scarce in the current literature. The newest and powerful pyrosequencing technology may solve this issue by sampling thousands of sequences from the same community. We conducted a study of diversity along a horizontal transect (ca. 120 km) and a depth profile (surface to bottom at ca. 2000 m) in the northwestern Mediterranean Sea, using this technology on the V6 region of the 16S rDNA gene and analyzed patterns of richness and evenness of marine free-living bacterial communities. A total of 201605 tag sequences were obtained from the 10 samples considered and clustered according to their similarity in 1200 operational taxonomic units (OTUs) per sample on average. We found a parallel decrease in richness and evenness from coast to offshore and from bottom to surface. We also observed a predominance of a few OTUs in each sample, while ca. 50% of all OTUs were found as singletons, which indicated that the community structures differed dramatically between sites despite the relative proximity and the physical connectivity between the samples. Despite these differences, using the 300 most abundant OTUs only was sufficient to obtain the same clustering of samples as with the complete dataset. Finally, both richness and evenness were negatively correlated with bacterial biomass and heterotrophic production.

Keywords: cascading, suspended particles, bottom nepheloid layer, Gulf o Lions, western Mediterranean

The analysis of a compilation of deep CTD casts conducted in the western Mediterranean after winter 2005 have documented the role that dense shelf water cascading (DSWC) plays in transporting suspended particulate matter from the coastal regions down to the basin. Deep CTD casts revealed the formation of thick and persistent bottom nepheloid layer (BNL) associated with the winter 2005 DSWCevent, which was not present in 2004. This BNL spread throughout the western Mediterranean basin and scaled in thickness with a thermo-haline anomaly generated by the mixture of dense waters formed by deep convection in the open sea and by cascading, being up to 1450 m thick at some locations. Excess of concentrations within the BNL could be observed to progress from the Gulf of Lions and Catalan margin towards the central part of the basin, reaching south of the Balearic Islands and west of Sardinia in May 2005, and covered the entire western Mediterranean basin in June 2006. BNL thickness and concentration diminished with distance away from its source and also with time, although its turbidity signal can still be detected at present (2010).

Keywords: Jellyfish - Metabolism - Zooplankton - Methods - Review - Aurelia - Rhizostoma - ETS

One of the main objectives of research on jellyfish is to determine their effects on the food web. They are voracious consumers that have similar diets to those of zooplanktivorous fish, as well as eating microplankton and ichthyoplankton. Respiration rates (RRs) can be used to estimate the amount of food needed to balance metabolism, and thereby estimate minimum ingestion. We compiled RRs for scyphozoan medusae in three suborders (Semeaostomeae, Rhizostomeae, and Coronatae) to determine if a single regression could relate RRs to mass for diverse scyphomedusan species. Temperature (7–30°C) was not a significant factor. RRs versus wet weight (WW) regressions differed significantly for semeaostome and rhizostome medusae; however, RRs versus carbon mass over five-orders of magnitude did not differ significantly among suborders. RRs were isometric against medusa carbon mass, with data for all species scaling to the power 0.94. The scyphomedusa respiration rate (SRR) regression enables estimation of RR for any scyphomedusa from its carbon mass. The error of the SRR regression was ±72%, which is small in comparison with the 1,000-fold variation in field sampling. This predictive equation (RR in ml O2 d−1 = 83.37 * g C0.940) can be used to estimate minimum ingestion by scyphomedusae without exhaustive collection of feeding data. In addition, effects of confinement on RRs during incubation of medusae were tested. Large medusae incubated in small container volumes (CV) relative to their size (ratios of CV:WW < 50) had RRs ~one-tenth those of medusae in relatively larger containers. Depleted oxygen during incubation did not depress RRs of the medusae; however, swimming may have been restricted and respiration reduced in consequence. We briefly review other problems with RR experiments and suggest protocols and limitations for estimating ingestion rates of jellyfish from metabolic rates.

Keywords: Pseudo-nitzschia, ITS, morphology, mating compatibility, toxin, Mediterranean Sea.

Proliferations of the genus Pseudo-nitzschia recur along the Catalan coast (NW Mediterranean) throughout the year. The establishment of 58 clonal cultures facilitated morphological studies with scanning electron microscopy (SEM) and ITS 5.8S rDNA sequence characterization. Moreover, strains of each species were examined with respect to sexual compatibility and toxicity. The results of the morphological and phylogenetic studies confirmed nine species of the genus Pseudo-nitzschia: P. brasiliana, P. calliantha, P. delicatissima clade A/del 2, P. arenysensis, P. fraudulenta, P. galaxiae, P. linea, P. multistriata and P. pungens clade I. Moreover, two Pseudo-nitzschia species, P. caciantha and P. cf mannii, could only be identified following SEM analysis of their morphology. None of the cultured strains of Pseudo-nitzschia analyzed produced domoic acid in amounts above the limit of detection. The current distributions of the Pseudo-nitzschia species in the Mediterranean Sea were plotted on maps, which led to the following observations: i) diversity within this genus is much greater than previously considered, ii) some species have a broad distribution (e.g. P. calliantha), iii) whereas the distribution of others is narrowly restricted (e.g. P. pungens clade I). Moreover, this study reports the first detection of P. linea in the Mediterranean Sea and is the first description of P. galaxiae and P. cf mannii along the Catalan coast. Morphological studies coupled with molecular biological characterization, mating tests and biogeographic distribution analyses provide a critical theoretical basis for testing and/or implementing the current phylogenetic framework in the genus Pseudo-nitzschia.

The deep sea, the largest biome on Earth, has a series of characteristics that make this environment both distinct from other marine and land ecosystems and unique for the entire planet. This review describes these patterns and processes, from geological settings to biological processes, biodiversity and biogeographical patterns. It concludes with a brief discussion of current threats from anthropogenic activities to deep-sea habitats and their fauna. Investigations of deep-sea habitats and their fauna began in the late 19th century. In the intervening years, technological developments and stimulating discoveries have promoted deep-sea research and changed our way of understanding life on the planet. Nevertheless, the deep sea is still mostly unknown and current discovery rates of both habitats and species remain high. The geological, physical and geochemical settings of the deep-sea floor and the water column form a series of different habitats with unique characteristics that support specific faunal communities. Since 1840, 28 new habitats/ecosystems have been discovered from the shelf break to the deep trenches and discoveries of new habitats are still happening in the early 21st century. However, for most of these habitats the global area covered is unknown or has been only very roughly estimated; an even smaller – indeed, minimal – proportion has actually been sampled and investigated. We currently perceive most of the deep-sea ecosystems as heterotrophic, depending ultimately on the flux on organic matter produced in the overlying surface ocean through photosynthesis. The resulting strong food limitation thus shapes deep-sea biota and communities, with exceptions only in reducing ecosystems such as inter alia hydrothermal vents or cold seeps. Here, chemoautolithotrophic bacteria play the role of primary producers fuelled by chemical energy sources rather than sunlight. Other ecosystems, such as seamounts, canyons or cold-water corals have an increased productivity through specific physical processes, such as topographic modification of currents and enhanced transport of particles and detrital matter. Because of its unique abiotic attributes, the deep sea hosts a specialized fauna. Although there are no phyla unique to deep waters, at lower taxonomic levels the composition of the fauna is distinct from that found in the upper ocean. Amongst other characteristic patterns, deep-sea species may exhibit either gigantism or dwarfism, related to the decrease in food availability with depth. Food limitation on the seafloor and water column is also reflected in the trophic structure of heterotrophic deep-sea communities, which are adapted to low energy availability. In most of these heterotrophic habitats, the dominant megafauna is composed of detritivores, while filter feeders are abundant in habitats with hard substrata (e.g. mid-ocean ridges, seamounts, canyon walls and coral reefs). Chemoautotrophy through symbiotic relationships is dominant in reducing habitats. Deep-sea biodiversity is among of the highest on the planet, mainly composed of macro and meiofauna, with high evenness. This is true for most of the continental margins and abyssal plains with hot spots of diversity such as seamounts or cold-water corals. However, in some ecosystems with particularly \"extreme\" physicochemical processes (e.g. hydrothermal vents), biodiversity is low but abundance and biomass are high and the communities are dominated by a few species. Two large-scale diversity patterns have been discussed for deep-sea benthic communities. First, a unimodal relationship between diversity and depth is observed, with a peak at intermediate depths (2000–3000 m), although this is not universal and particular abiotic processes can modify the trend. Secondly, a poleward trend of decreasing diversity has been discussed, but this remains controversial and studies with larger and more robust data sets are needed. Because of the paucity in our knowledge of habitat coverage and species composition, biogeographic studies are mostly based on regional data or on specific taxonomic groups. Recently, global biogeographic provinces for the pelagic and benthic deep ocean have been described, using environmental and, where data were available, taxonomic information. This classification described 30 pelagic provinces and 38 benthic provinces divided into 4 depth ranges, as well as 10 hydrothermal vent provinces. One of the major issues faced by deep-sea biodiversity and biogeographical studies is related to the high number of species new to science that are collected regularly, together with the slow description rates for these new species. Taxonomic coordination at the global scale is particularly difficult, but is essential if we are to analyse large diversity and biogeographic trends. Because of their remoteness, anthropogenic impacts on deep-sea ecosystems have not been addressed very thoroughly until recently. The depletion of biological and mineral resources on land and in shallow waters, coupled with technological developments, are promoting the increased interest in services provided by deep-water resources. Although often largely unknown, evidence for the effects of human activities in deep-water ecosystems – such as deep-sea mining, hydrocarbon exploration and exploitation, fishing, dumping and littering – is already accumulating. Because of our limited knowledge of deep-sea biodiversity and ecosystem functioning and because of the specific life-history adaptations of many deep-sea species (e.g. slow growth and delayed maturity), it is essential that the scientific community works closely with industry, conservation organisations and policy makers to develop robust and efficient conservation and management options.

Keywords: Biodiversity; canyon; fishing impact; megabenthos; Northwestern Mediterranean.

The composition and structure of megabenthic communities in the Blanes canyon and adjacent open margin (Northwestern Mediterranean) were studied. The aim was to assess the effect of the canyon and commercial fishing intensity on the community composition and structure of benthic megafauna by (i) describing the megabenthic community composition, (ii) quantifying faunal abundance and biomass and (iii) describing community structure with MDS analyses and biodiversity indices. The results are compared between three sites (canyon head, canyon wall and open margin) located between 435 m and 700 m. Samples were collected using a commercial bottom trawl between April 2003 and March 2004. These sites are exploited by the local fishing fleet that targets the rose shrimp Aristeus antennatus. A total of 131 megabenthic species were identified from the three sites, with fishes and decapod crustaceans being the most speciose, most abundant and of higher biomass. The species richness, abundance and biomass of non-crustacean invertebrates were low. There were no significant differences in total abundance and biomass between the three sites. However, community structure analysis suggests that the open margin community is significantly different from the canyon head and canyon wall, with a lower species richness, lower diversity and lower evenness. The open margin community also reflects a higher degree of disturbance compared to the two canyon habitats. The results indicate that there is a canyon effect on the community structure of benthic megafauna, but this may be modulated by differing fishing pressure, which adds an additional factor to margin heterogeneity.

Keywords: Stichopus regalis; Commercial cucumber; NW Mediterranean; Trawl fisheries

Stichopus regalis is a common sea cucumber that is found in a wide depth range in the Mediterranean beyond 50 m depth. Its five longitudinal muscular bands are a culinary delicacy. It is the most expensive seafood product on the Catalan market, and it can reach up to 130 €/kg. Despite its ecological and economical importance, information related to this species is very scarce. The population inhabiting the Mallorca and Menorca continental shelf and slope was studied using data from several different surveys conducted from 2001 to 2009. The spatial distribution of the royal cucumber is strongly aggregated. The population showed a multimodal length-frequency distribution, with individuals ranging from 65 to 295 mm in length. Abundance was highest between 100 and 299 m depth and sizes were largest between 50 and 299 m depth. The length–weight relationship indicates a negative allometry, explained by the fact that the thickness of some parts of the body wall appears to be independent of the size of the individual. Although S. regalis has a high price, due to its relatively low abundance it is not a particular target species of the multispecies trawl fisheries, and is captured as a by-catch, with a mean catch per unit effort of 1.78 kg per boat and day. The edible part corresponds to 9.81% of the drained weight of the whole animal.

Keywords: VPA análisis de pseudocohortes, programa VIT, precisión, recomendaciones de uso.

Calidad de los parámetros poblacionales derivados del análisis de pseudo-cohortes de vit. – Las comparaciones de los resultados del modelo VIT con los del método de VPA, empleado para la evaluación del stock de bacalao en el Skagerrak, Mar del Norte y la parte oriental del Canal de la Mancha, muestran que las tendencias generales de la mortalidad por pesca y del tamaño del stock aparecen bien representadas en un período de tres décadas (1963-1992). No obstante las implicaciones de la asunción de equilibrio (estado estacionario) del modelo VIT son muy grandes y fuerzan importantes variaciones interanuales de la mortalidad por pesca, especialmente en aquellos años en que la composición de edades muestra el efecto de clases anuales fuertes. Los parámetros estimados por VIT deben ser cuidadosamente interpretados cuando el stock evaluado presenta una fuerte reducción de su abundancia y una elevada explotación ya que esta condición lo aleja del estado estacionario. Las estimaciones de la biomasa virgen son muy variables, extremadamente altas y dependientes de las estimaciones del stock. No se recomienda su uso como punto de referencia de una biomasa realista en un contexto de gestión pesquera. Las estimaciones de F0.1 y Fmax son similares a las estimaciones de ICES. Los resultados del modelo permiten la obtención de conclusiones más bien cualitativas sobre el estado de los recursos marinos en referencia a la tasa de explotación. Las conclusiones cuantitativas sobre la evaluación del estado de explotación son recomendables solamente en el caso de que se aplique el modelo a una serie corta de datos anuales consecutivos y cuando la variación de los parámetros estimados sea razonablemente baja. Los resultados del modelo pueden fundamentar las bases de un correcto asesoramiento del estado real del stock así como predicciones de biomasa, bajo diversas alternativas de gestión, a corto y medio plazo.

Keywords: Contour descriptors - Elliptic Fourier descriptors - Shape analysis - Feature extraction

In this paper we propose a new contour descriptor for reconstructing fish otolith contours that uses half the number of coefficients needed by the classical elliptical Fourier descriptors (EFDs) for the same accuracy. The efficiency of the proposed shape descriptor has been tested with two different species, Liza aurata and Liza ramada, belonging to the family Mugilidae (http://aforo.cmima.csic.es), and two populations (from the USA and Canada) of the family Merlucciidae. These groups are characterized by high similarity between species; therefore, accurate, detailed shape analyses of their otoliths can help to identify and discriminate morphologically close species or different populations. For comparative purposes the descriptor was also tested with specimens of Mullus barbatus (Family Mullidae). For a certain number of coefficients (<50) the new descriptor clearly outperforms the reconstruction accuracy of the EFD.

Keywords: Geophysics, image analysis , remote sensing , sea coast , surface waves

Nearshore sandbars, an important natural defense mechanism of the beaches, can be monitored using shore-based video systems. Before studying bar dynamics with video images, we must establish the relationship between the real bar positions and the videoed bar positions (detected by the preferential wave breaking on the shallows). This analysis becomes essential in the two studied tideless beaches of Barcelona due to the critical differences with respect to the sites studied previously. Bogatell beach is terraced (without a trough) in more than 50% of the profiles. There, the videoed barlines are a good proxy of the terrace edge position. In La Barceloneta beach, with dominance of barred profiles, the videoed barlines better represent the bar crest position. On average, the obtained distances between real and videoed bar positions ${rm Delta} r$ are 10–15 m, with the videoed barlines located shoreward. Changes in the bathymetric profile shape and the root-mean-squared wave height $H_{{rm rms}}$ induce a variability of ${rm Delta} r$ of 16 m in La Barceloneta and 13 m in Bogatell. This apparent variability masks the real changes in bar position and should preferably be reduced before further analysis. As a highly significant correlation between ${rm Delta} r$ and $H_{{rm rms}}$ is detected in the two beaches, the proposed reduction method consists of sampling at a specific range of $H_{{rm rms}}$. This diminishes the variability by 10% to 14 m in La Barceloneta and 11 m in Bogatell. This paper confirms the suitability of using video systems for monitoring - - bars and terraces in the Barcelona beaches.

Keywords: Silicoflagellates; Sediment trap; Western Mediterranean; NAO; ENSO

A total of 337 samples collected from five sediment traps located in the Gulf of Lions, Catalan margin and the Alboran Sea have been analyzed in order to study the previous termseasonal, interannualnext term and geographical distributions of silicoflagellate fluxes in the Western Mediterranean. As a general trend, maximum fluxes of silicoflagellate skeletons always occurred during the spring bloom; i.e. during the winter–spring transition, while minimum fluxes were recorded during summer, characterised by a strong stratification and oligotrophic conditions. However, the sediment trap record of the Catalan margin did not exhibit any clear previous termseasonalnext term signal, probably owing to the fertilizing effect of the rivers Llobregat and Besos. Regarding previous terminterannual variability,next term no clear relationship between the NAO (North Atlantic Oscillation) and the silicoflagellate fluxes was found. In contrast, the silicoflagellate assemblages from the Alboran Sea and the Gulf of Lions responded with low fluxes and a delay in their annual maximum to the anomalous conditions elicited by the 1997–98 El Niño Event. Furthermore, the 2003 summer heat wave over the Western Mediterranean had similar repercussions on the silicoflagellate spring maximum 2004 in the Gulf of Lions. Three silicoflagellate species were identified in the samples, following the taxonomic concepts of Throndsen (1997): Dictyocha fibula (Ehrenberg), Dictyocha speculum (Ehrenberg) and Octactis octonaria (Ehrenberg) Hovasse 1946. D. fibula was cosmopolitan and the dominant species at all sites, always accounting for more than 80%. Moreover, its maximum fluxes were recorded in those sampling sites which were under the influence of high nutrient concentrations caused by the river input. D. speculum was only recorded in the northern locations, which suggests an affinity for colder water masses. In contrast, O. octonaria was restricted to the Alboran Sea stations, where temperatures reached the highest values and nutrients were scarcer.

Keywords: Food web - ADBM - Diet overlap - Plankton - Co-ocurrence - Body size - Oligotrophic lake - Ruidera Natural Park

In an attempt to explain ‘Why are there so many kinds of animals?’ G.E. Hutchinson highlighted the food web context to suggest that diversity of primary producers should allow consumer richness to be maintained as a result of their adaptive foraging. Co-existence of consumers is then made possible when species differ in body size and thus only a minor diet overlap occurs. All these ideas are still major topics in ecological research and some have been re-examined in order to provide mechanistic explanations of species richness versus connectance relationships in food web structure. The effect of body size as a determinant of diet, jointly with the assumption that individuals are adapted to switch their diet in order to maximise energy gain, have been combined in recent years to develop the Allometric Diet Breadth Model (ADBM). This model, successful for plankton communities, enables us to determine the specific resource–consumer links and then evaluate the diet breadth and test whether the diet overlaps. Here, we apply the ADBM to infer the feeding linkages within a freshwater planktonic community of a Spanish oligo-mesotrophic lake and three spatial partitions of it. ADBM treats phytoplankton species and bacteria as resources and each consumer species (ciliates, rotifers and crustaceans) as both consumers and resources. We applied ADBM to water-column integrated- and single-layered plankton communities to test the importance of the diet on structuring the plankton. If a given pair of species that co-occur in the whole vertical community overlap their diet more than when they occur in the three layers separately, this means that they will never co-exist and are hence overdispersed (segregated). Not all species pairs that have a weak diet overlap when belonging to the whole water-column community co-exist in water-layered communities. Hence, the richer, whole water-column community would then have lower diet overlap than spatially segregated communities. Therefore, the hypothesis of diet breadth of Hutchinson (The American Naturalist 93: 145–159, 1959) explains community structure throughout the water column, and its deviations may be forced abiotically.

Incubation experiments with axenic cultures of four common phytoplankton species of the genera Chaetoceros, Skeletonema, Prorocentrum, and Micromonas were performed to test for the production of fluorescent dissolved organic matter (FDOM) by marine phytoplankton. Our results prove that the four species exuded both fluorescent protein-like and marine humic–like materials in variable amounts, with more production by the diatoms Chaetoceros sp. and Skeletonema costatum and less by Prorocentrum minimum. Whereas the exudation of protein-like substances by healthy phytoplankton cells has been recognized, the in situ production of marine humic-like substances is still a matter of debate. Using axenic cultures, we demonstrate unequivocally that phytoplankton can directly contribute to the autochthonous production of colored humic-like substances in the ocean. Extrapolation of these findings to the field indicates that about 20% of the marine humic–like substances produced in the highly productive coastal upwelling system of the Ria de Vigo could originate from growing phytoplankton. Therefore, the exudation of FDOM by marine phytoplankton should be considered in future studies of the dynamics of colored DOM in marine systems.

Keywords: contourite depositional system; sediment drift; seismic stratigraphy; Mediterranean Outflow Water; North Iberian margin; Le Danois Bank

The Le Danois Contourite Depositional System (CDS), located in an intraslope basin along the Cantabrian margin, is unique with respect to the known sedimentary systems along the upper slope of the Biscay margin. Whereas the steep Biscay slopes are dominated by downslope processes, the Le Danois CDS has been generated by alongslope processes and has a strong potential to contain a record of the Neogene palaeoceanography. This paper will focus on the onset, development and present-day functioning of this system with respect to its unique morphological control and the responsible local oceanographic processes. New bathymetric and seismic reflection data show that the past and present Le Danois CDS is shaped by the Mediterranean Outflow Water, conditioned by seafloor irregularities and two topographic highs; the large Le Danois Bank and the smaller Vizco High. The seismic stratigraphic analysis carried out on the contourite deposits has allowed to identify 3 seismic sequences, separated by 3 major regional discontinuities. Changes in depositional styles, the vertical stacking of seismic units and the nature of the discontinuities suggest a correlation with the development of the Cadiz CDS and well-known palaeoceanographic events along the NE Atlantic margin. The first clues for bottom-current deposits are identified in the Lower Sequence, which is developed after tentatively the Lower Pliocene. The drift deposits of both the Lower and Middle Sequences were confined into two palaeobasins within the intraslope basin. However, from the Middle Pleistocene Revolution (0.9 Ma) onwards, the contouritic deposition is intensified due to the switch to a “full glacial” mode with 100 ka cyclicity. This has allowed the development of the present-day depositional and erosive features, such as respectively elongated mounded and separated drifts, plastered drifts, moats and slide scars.

Keywords: Cyanidium caldarium; Photosynthesis; Silica; Encapsulation; Cellular interaction; Biomineralization

Cyanidium caldarium (Tilden) Geitler SAG 16.91 has been encapsulated within a porous silica host structure to target novel photosynthetic hybrid materials suitable for use in solar cells or CO2 fixation. C. caldarium cells are both thermophilic and acidophilic; on account of these tolerances the hybrid materials could be employed in more extreme heat conditions. TEM highlights that the external cell membrane can remain intact after encapsulation. The images reveal an alignment of silica gel around the external membrane of the cell, providing evidence that the cell wall acts as both a nucleation and polymerisation site for silica species and that the silica scaffold formed by the aggregation of colloidal particles, generates a porosity that can facilitate the transport of nutrients towards the cell. Epifluorescence microscopy and UV–visible spectroscopy have revealed the preservation of photosynthetic apparatus post-immobilisation. Productivity studies showed how the presence of silica nanoparticles within the matrix can adversely interact with the exterior cellular structures preventing the production of oxygen through photosynthesis.

We characterized the effect of an inshore–offshore gradient in Fe in the northeast subarctic Pacific on the bacterioplankton and phytoplankton assemblages and on the microbial cycling of particulate and dissolved dimethylsulfoniopropionate (DMSPp and DMSPd) and dimethylsulfide (DMS). Averaged concentrations of total dissolved Fe (TDFe) decreased linearly with increasing water density along the transect, from 3.4 nmol L-1 at the two inshore stations to 1.0 nmol L-1 at the offshore stations, as a result of the vertical and lateral mixing between the Fe-rich coastal water and the Fe-poor Alaska Current. The Fe-rich inshore stations were dominated by diatoms and characterized by low DMSPp : chlorophyll a (Chl a) ratios (ca. 26 nmol µg-1) and bacterial DMS yield (< 4%). In contrast, the Fe-poor offshore stations were dominated by prymnesiophytes and exhibited high DMSPp : Chl a ratios (ca. 84 nmol µg-1) and bacterial DMS yield (8%). Chl a, DMSPp, and the abundance of total bacteria and three bacterial clades (Gammaproteobacteria, Roseobacter, and Betaproteobacteria) were positively correlated with the TDFe gradient. At the Fe-poor offshore stations, the positive correlation found between TDFe and the DMSPp : Chl a ratios suggests that Fe supplied by mixing stimulated DMSP production in the prymnesiophyte-dominated assemblage, a response similar to that generally observed during the first days of most of the large-scale ocean iron fertilizations (OIFs). These results suggest that the stimulation of DMSP production takes place whatever the Fe supply mode: atmospheric dust deposition, as simulated by OIFs, or mixing, as reported in this study.

Keywords: bivalves, geographic distribution, bathymetric distribution, beach morphology, river proximity.

Eecological aspects of 75 megabenthic bivalve species found on the south coast of Portugal (from Vila Real to Sagres) were studied based on the information provided by seasonal bivalve surveys from 2000 to 2007 (8600 hauls, simultaneously using a razor shell dredge and a clam dredge). Of the 75 species identified, 36 occurred less than 30 times, and thus were considered rare in the area. The remaining 39 bivalves were analysed according to their occurrence, bathymetric distribution, geographic preferences, seasonal preferences, burying-depth, beach exposure and river mouth proximity. All species belonging to the Pharidae and Solenidae families (razor shells) and most Tellinidae were significantly more frequent in the razor shell dredge (indicating deeper burying in the sediment), whilst the families Cardiidae and Donacidae were significantly more frequent in the clam dredge (indicating that these species are probably closer to the sediment surface). As for the season, most bivalve species occurred similarly in both seasons (19 sp; 49%), but a large proportion were more abundant during the autumn surveys (17 sp., 44%), whereas only three species were commoner during the spring surveys. Most species belonging to the families Cardiidae and Mactridae were commoner in the autumn surveys. Tthe spatial distribution differed between species and cluster analysis identified four communities with greater geographic affinity. Species belonging to the family Cardiidae were preferably found in the western part (WB) and the eastern part (S) of the study area, whereas the families Donacidae, Mactridae and Tellinidae occurred mainly in the central area (EB) and the eastern (S) coastal sectors. Overall, shallower species (modal depth at 3-6 m) showed greater occurrences and abundances than the deeper ones, and the depth pattern observed did not change between seasons. Donacidae and Mactridae (except Mactra glauca) were represented essentially by shallow species, whereas Cardiidae (except Acanthocardia tuberculata and Cerastoderma edule) included mostly species occurring in deeper waters. Bathymetric sequence of species distribution within some families was observed.

Keywords: ellyfish - Ichythyoplankton - Fish - Front - Siphonophore - Hydromedusae

Pelagic cnidarians are important consumers of zooplankton and ichthyoplankton in the world’s oceans, and thus harm fisheries as competitors and predators of fish. This study examined the inshore-offshore distribution of pelagic cnidarians and the trophic ecology of Pelagia noctiluca ephyrae (<12 mm diameter) and larger medusae in late spring 1995 in the NW Mediterranean Sea. The distribution of pelagic cnidarians was closely related to the presence of the shelf-slope front with most species mainly concentrated close to the front. Meroplanktonic antho- and leptomedusae predominated in coastal waters and more holoplanktonic trachy- and narcomedusae occurred both in shelf and open sea waters. P. noctiluca was more abundant than other medusae, including hydromedusae. Siphonophores, particularly Muggiaea atlantica, outnumbered medusae at most stations. The diet of P. noctiluca ephyrae contained mainly copepods, but ~12% of the prey were fish larvae. P. noctiluca exhibited positive prey selection for chaetognaths and mollusc larvae in day and night samples, but fish larvae were positively selected only at night. These differences may be related to the diel vertical distributions of P. noctiluca and their prey. Most of the ingested fish larvae belonged to the family Myctophidae, but anchovy and sparid larvae also were found in the gastric pouches. The size of ingested fish larvae increased as ephyra diameter increased; however, in the larger medusae (>12 mm) the number of prey increased with medusa size rather than the size of the larvae. The temporal and spatial co-occurrence of P. noctiluca with early life stages of fish suggests that P. noctiluca may be an important predator on summer ichthyoplankton.

Keywords: Error budget , Soil Moisture and Ocean Salinity (SMOS) , retrieval , salinity

The Soil Moisture and Ocean Salinity mission will provide sea surface salinity maps over the oceans, beginning in late 2009. In this paper an ocean salinity error budget is described, an analysis needed to identify the magnitude of the error sources associated with the retrieval. Instrumental, external noise sources, and geophysical errors have been analyzed, stressing their relative impact. This paper includes results from previous studies, addressing the impact of multisource auxiliary sea surface temperature and wind speed data on the final salinity error. It provides, moreover, a sensitivity analysis to the uncertainty of the auxiliary salinity field. Salinity retrieval has been addressed in a wide set of configurations of the inversion algorithm.

Towards an operational SMOS brightness temperature monitoring over oceans, preliminary results of the joint effort between the European Centre for Medium-Range Weather Forecasts (ECMWF) and SMOS Barcelona Expert Centre (SMOS-BEC) are described. Both ECMWF and also SMOS-BEC averaged brightness temperature maps have been produced to help in identifying systematic instrumental patterns and assessing relevant oceanic features present in the SMOS measurements.

Preliminary results obtained during the commissioning phase of the Soil Moisture and Ocean Salinity (SMOS) mission are described, devoting special attention to the characterization of the systematic errors found in the measurements and the corresponding impact in the retrieved salinity product. The identified issues and objectives to consolidate and improve the processing chain are also described.

Keywords: SMOS mission, Salinity retrieval, Bias mitigation

Preliminary results obtained during the commissioning phase of the Soil Moisture and Ocean Salinity (SMOS) mission are described, devoting special attention to the characterization of the systematic errors found in the measurements and the corresponding impact in the retrieved salinity product. The identified issues and objectives to consolidate and improve the processing chain are also described.

Keywords: SMOS mission, Salinity retrieval, Bias mitigation

In this paper, first preliminary results obtained during the commissioning phase of the Soil Moisture and Ocean Salinity (SMOS) mission are described, devoting special attention to the characterization of the systematic errors found in the measurements and the corresponding impact in the retrieved geophysical product. The identified issues and objectives to consolidate and improve the processing chain are also described

Keywords: Bacteria – Arctic – Global change – Functional diversity – Ectoenzyme – Biolog

Global warming and the associated ice melt are leading to an increase in the organic carbon in the Arctic Ocean. We evaluated the effects of ice melt on bacterioplankton at 21 stations in the Greenland Sea and Arctic Ocean in the summer of 2007, when a historical minimum of Arctic ice coverage was measured. Polar Surface Waters, which have a low temperature and low salinity and originate mainly from melted ice, contained a very low abundance of bacteria (7.01 × 105 ± 2.20 × 105 cells ml−1); however, these bacteria had high specific bacterial production (2.40 ± 1.61 fmol C bac−1 d−1) compared to those in Atlantic Waters. Specifically, bacterioplankton in Polar Surface Waters showed a preference for utilizing carbohydrates and had significantly higher specific activities of the glycosidases assayed, i.e. β-glucosidase, xylosidase, arabinosidase and cellobiosidase. Furthermore, bacterioplankton in Polar Sea Waters showed preferential growth on some of the carbohydrates in the Biolog Ecoplate, such as d-cellobiose and N-acetyl-d-glucosamine. Our results suggest that climate change and the associated melting of Arctic ice might induce changes in bacterioplankton functional diversity by enhancing the turnover of carbohydrates. Since organic aggregates are largely composed of polysaccharides, higher solubilization of aggregates might modify the carbon cycle, weaken the biological pump and have biogeochemical and ecological implications for the future Arctic Ocean.

Heat and water exchanges in the ocean occur almost exclusively at the surface. As water compressibility is very low, stratification of the fluid is expected and horizontal motion is predominant in the sea interior. Among the few processes that may introduce a vertical component in the water motion are those that increase surface water density by freezing, cooling or evaporation. Those processes triggering convective motion are enhanced by cold surface air, dry wind and low solar radiation. Therefore, convective cells are more likely to occur when the temperature of the air at the sea surface is lower than sea surface temperature. Conversely, rain, river runoff, solar heating, calm and condensation at surface enhance stratification. Convective motion at sea has several scales ranging from few meters at the upper ocean, causing the surface mixed layer, to the entire water column, in what is known as deep convection. Only few places in the world ocean are suitable for deep convection, and only under particular weather conditions. In this paper, a brief review of the response to these particular conditions in the NW Mediterranean is presented in what is known as dense water formation. The violent sinking and spreading of water parcels that reach the deep sea floor in few hours is described. These are “hidden” mediterranean storms, occurring under the sea surface, “on the other side of the mirror”.

Keywords: dimethylsulfide; dimethylsulfoniopropionate; dilution technique; microzooplankton; grazing

With the aim of re-examining the suitability of the dilution technique in studies of dimethylated sulfur cycling in the sea, we conducted two types of experiments: one with a simplified food chain of cultured organisms, and secondly with field-sampled natural communities. In the case of Isocrhysis galbana being grazed by Oxyrrhis marina, algal growth (μ) and grazing mortality (m) rates calculated using either chlorophyll a (Chla) or particulate dimethylsulfoniopropionate (DMSPp) were very similar. By means of a parallel incubation of prey with no predator, the regression-derived phytoplankton μ was validated. Net 24-h changes in DMS concentration showed a linear trend against DMSP grazing rates, with a slope that allowed estimation of the rate of DMS production due to grazing. When the method was applied to natural communities from coastal NW Mediterranean waters, μ values of the bulk Chla-containing phytoplankton assemblage were higher than that of the DMSP-containing algae, but m were not significantly different. The grazing-mediated DMS production rate was successfully estimated, and parallel incubations with and without a specific inhibitor of bacterial DMS metabolism allowed us to estimate the gross DMS production by the whole community and the bacterial DMS consumption rate. A further experiment showed that bacterial consumption was not affected by dilution.

Keywords: Loligo vulgaris; Reproduction; Maturation; Seasonality; General Additive Models; Western Mediterranean

Loligo vulgaris samples were obtained monthly from October 2003 to December 2005 on board commercial trawlers from two ports (Cambrils and Roses) off the Catalan coast (NW Mediterranean). The main aim of this work was to understand what controls the onset of the maturation process in L. vulgaris: size, nutritional state, fishing season, or a combination of some of these elements. We investigated the relationships between gonad weight (ovary/testis) and total body weight, eviscerated weight, mantle length, digestive gland weight, nidamental and accessory glands weight and capture date (month). Generalised Additive Models (GAMs) were applied. The results indicated that gonad weight variation, in both the ovary and testis, was explained by the month of capture. There was also evidence of an opposite seasonality between gonads and eviscerated weights, possibly indicating remobilization of somatic mantle tissue to grow the gonads in both males and females. There was a positive relationship between ovary weight and size, measured as dorsal mantle length (DML), at DML >14 cm, which indicates the size at which maturation starts. The digestive gland would not take a relevant participation as an organ of storage and therefore in the energetic expense during the process of maturation. Nidamental and accessory reproductive glands weight was also positively related to ovary weight. The relationships between the different variables analyzed were more complex in males than in females. They showed, however, a clear energy transfer between testis weight and spermatophoric complex weight. The results also suggested the existence of two or more growth patterns leading to different sizes at maturity in L. vulgaris males.

This study analyzes the morphodynamic behaviour under storm conditions of La Barceloneta, an artificial ambayed beach, previous and after the construction of a detached breakwater using viedo image measurement. In general, the decreases in the emerged beach area due to storm events were higher after the construction of the detached breakwater. So the detached breakwater built in La Barceloneta beach do not seem to be completely effective in preventing beach erosion during the most energetic storms events

Keywords: Gorgonians · Red coral · Mediterranean Sea · CITES Appendix II listing

A recent article by Bruckner (2009; Mar Ecol Prog Ser 397:319–332) focused on population decline in the commercially exploited Mediterranean red coral Corallium rubrum. Bruckner (2009) used data on coral size structure and reproductive output gathered by a variety of sampling methods in different populations: Data on overharvested shallow-water populations (which are generally made up of crowded, small-sized colonies) were combined with the small amount of data available on deep-water populations (which consist of larger, sparse colonies); the latter have become the main target for commercial harvesting nowadays. In our opinion, the conclusions in Bruckner (2009) did not fully reflect the heterogeneity and the limits of the data set. Collection of sound demographic data through broader, coordinated research applying standard procedures to different populations is required for a reliable analysis of Corallium rubrum population dynamics.

Keywords: Hydrocarbon; Fish; Water Framework Directive; Biomarkers; Oil spill; EROD

Oil spills are an importance source of polycyclic aromatic hydrocarbons (PAHs) in the aquatic environment. Intertidal communities are particularly sensitive since most organisms from these ecosystems are sessile or present reduced mobility. Hence, it is important to validate the use of resident species as sentinels to characterize the impact of oil spills on the rocky shores and the improvement during the restoration process. Recently the advantages of using the shanny Lipophrys pholis in pollution monitoring within the northwestern Atlantic coast has been pointed out. Therefore, with the aim of further validating the use of L. pholis in pollution monitoring associated with petrogenic hydrocarbon contamination, a multi-biomarker approach study was carried out 1 week after a moderate oil spill from the waste treatment plant (WTP) of the major Portuguese refinery in the north of Portugal (Petrogal). Fish collected at 2 km from the accident displayed a significant induction of ethoxyresorufin-O-deethylase activity (EROD) and fluorescent aromatic compounds (FACs) in bile (up to a 5-fold induction) in comparison with the pre-spill scenario, and a 15% induction in erythrocytic nuclear abnormalities (ENA), a biomarker of genotoxicity. In contrast, no significant differences were recorded in the reference site. In order to better characterize the time-course accumulation of FACs in bile after a PAH insult, laboratory exposure of L. pholis to benzo[a]pyrene (B[a]P) was performed. A clear dose–response accumulation of B[a]P metabolites was observed that closely reflected nominal exposure concentrations already after 3 d. Overall, the findings of the present study highlight the potential of L. pholis in pollution monitoring dealing not only with chronic contamination, but also with oil spill accidents of a moderate scale. Taking into consideration that EROD and FACs determinations in L. pholis are cost effective, rapid and easy to use, they offer a great potential to be incorporated into risk assessment of PAHs in the scope of national monitoring programs and the European Water Policy legislation.

Keywords: red and blue shrimp, Aristeus antennatus, mtDNA, 16S rDNA, gene flow, depth distribution, Western Mediterranean, metapopulation.

The red and blue shrimp, Aristeus antennatus, inhabits deep shelf waters in the Mediterranean Sea, where the shallower portion of its distribution supports a large commercial fishery. Recent prospecting surveys in the western Mediterranean have detected virgin stocks dwelling at more than 1000  m, but the extent of gene flow between the exploited shallow-dwelling stock and the deep-dwelling stock is unknown. To investigate the genetic structure of the population and estimate the depth component of gene flow, a portion of the mitochondrial DNA 16S gene (547  pb) was sequenced for 321 individuals from four different depths (350, 700, 1100 and 1500 m) at a location in the Catalan Sea. Haplotype and nucleotide diversity values were low and did not significantly differ across depths. Analysis of molecular variance showed no significant genetic differences between depths. Mismatch distribution and neutrality tests indicated that A. antennatus has undergone recent demographic expansion in the two shallowest layers. Our results suggest that the species is genetically structured as a sort of metapopulation in which gene flow that occurs during the larval and juvenile stages, when larvae are carried downstream and juveniles are carried upstream by cascading, plays an important role in the resilience of the exploited layers.

Keywords: temperature, bacteria, heterotrophic nanoflagellate, grazing, metabolic theory of ecology, activation energy

Previsions of a warmer ocean as a consequence of climatic change point to a 2–6°C temperature rise during this century in surface oceanic waters. Heterotrophic bacteria occupy the central position of the marine microbial food web, and their metabolic activity and interactions with other compartments within the web are regulated by temperature. In particular, key ecosystem processes like bacterial production (BP), respiration (BR), growth efficiency and bacterial–grazer trophic interactions are likely to change in a warmer ocean. Different approaches can be used to predict these changes. Here we combine evidence of the effects of temperature on these processes and interactions coming from laboratory experiments, space-for-time substitutions, long-term data from microbial observatories and theoretical predictions. Some of the evidence we gathered shows opposite trends to warming depending on the spatio-temporal scale of observation, and the complexity of the system under study. In particular, we show that warming (i) increases BR, (ii) increases bacterial losses to their grazers, and thus bacterial–grazer biomass flux within the microbial food web, (iii) increases BP if enough resources are available (as labile organic matter derived from phytoplankton excretion or lysis), and (iv) increases bacterial losses to grazing at lower rates than BP, and hence decreasing the proportion of production removed by grazers. As a consequence, bacterial abundance would also increase and reinforce the already dominant role of microbes in the carbon cycle of a warmer ocean.

Keywords: Alexandrium minutum, Alexandrium catenella/tamarense complex, Dinoflagellate cysts, Diversity, Mediterranean Sea, Human impact

Studies were conducted on dinoflagellate cyst assemblages from two semi-enclosed areas of the Western Mediterranean Sea subject to high human impact, Arenys de Mar harbor and the Gulf of Olbia. Sediment cores were taken from seven stations (December 2006 and August 2007) in Arenys and from eight (October 2006) and ten (May 2007) stations in Olbia. Of the 42 morphotypes found in the sediments collected at the two sites, 27 were identified at the species level, representing 10 genera. The most common cysts were those of Scrippsiella trochoidea, Scrippsiella sp. 2, Gymnodiniales type 1, and Scrippsiella precaria. A number of the morphotypes had not been previously described in the literature. Total cyst abundances varied substantially between the two surveys, with an increased total density in Arenys and a decrease in Olbia. However, at the latter site, a higher abundance of cysts was recorded at more confined sampling stations. Calcareous Peridiniales, belonging to the genus Scrippsiella, dominated the cyst assemblages of both sites, while at some stations higher numbers of Gymnodiniales (Olbia) and Gonyaulacales (Arenys) were determined. Cysts of the toxic species Alexandrium minutum and A. catenella/tamarense were also detected. A. minutum was present at both sites whereas A. catenella/tamarense was found only in Olbia. Peridinium quinquecorne was recovered in the sediments of both sites. In Olbia, cysts of this species were present at high densities and were detected even in deep sediments. Species such as Pentapharsodinium cf. tyrrhenicum, Scrippsiella crystallina, S. lachrymosa, S. precaria, S. trochoidea, Protoperidinium avellanum, P. claudicans, P. compressum, P. conicum, P. cf. minutum, P. oblongum, P. pentagonum, P. subinerme, and Zygabikodinium lenticulatum were not detected as motile stages in the study areas. The results of this study, the first on dinoflagellate cyst assemblages at these two sites, further our knowledge of cyst diversity and confirm the importance of embayments and hydrographically confined areas as reservoirs for planktonic dinoflagellates.

Keywords: Cyanobacteria; diversity; gene expression; microbial mat; nitrogen fixation

The structure of the microbial community and the diversity of the functional gene for dinitrogenase reductase and its transcripts were investigated by analyzing >1400 16S rRNA gene and nifH sequences from two microbial mats situated in the intertidal zone of the Dutch barrier island Schiermonnikoog. Although both microbial mat communities were dominated by Cyanobacteria, they differed with respect to the composition of the total bacterial community. Proteobacteria-related sequences were retrieved as the second most abundant group higher up in the littoral (Station I), whereas Bacteroidetes were the second most abundant group at the low water mark (Station II). The diazotrophic (nitrogen-fixing) communities at both stations were also different, but had more operational taxonomic units in common than the total bacterial community. Denaturing gradient gel electrophoresis also revealed differences in the total bacterial and diazotrophic community in two consecutive years. Analysis of the expression of nifH at Station I showed a discrepancy between the present and the active diazotrophic community. Transcript abundances of the different diazotrophs changed over a 24-h cycle and were dominated by cyanobacterial lineages in the daytime, while Gammaproteobacteria peaked at night. These variations might be responsible for the pattern in nitrogenase activity observed in these mats.

Phytoplankton-produced dimethylsulfoniopropionate (DMSP) provides underwater and atmospheric foraging cues for several species of marine invertebrates, fish, birds, and mammals. However, its role in the chemical ecology of marine planktonic microbes is largely unknown, and there is evidence for contradictory functions. By using microfluidics and image analysis of swimming behavior, we observed attraction toward microscale pulses of DMSP and related compounds among several motile strains of phytoplankton, heterotrophic bacteria, and bacterivore and herbivore microzooplankton. Because microbial DMSP cycling is the main natural source of cloud-forming sulfur aerosols, our results highlight how adaptations to microscale chemical seascapes shape planktonic food webs, while potentially influencing climate at the global scale.

Keywords: comparative approach, fishing impacts, indicator, upwelling

A suite of ecological indicators was selected for communicating, in a comparable way, how fishing affects the state of several upwelling ecosystems and others in which small pelagic fish play key ecological roles. Detailed background and understanding of system-specific processes and changes is needed for proper interpretation of results. In particular, environmental forcing is important in driving dynamics in upwelling systems; fishing impacts cannot be understood without understanding the corresponding dynamics of the environment. The Saharan Coastal (Morocco) and southern Benguela, both having experienced upsurges in low-trophic-level species, differed from other ecosystems when considering indicator trends. The ecosystem off Portugal emerged as showing reduced signs of fishing impacts in recent years, although the change may also be reflecting climate change favouring recruitment and abundance of demersal stocks. The indicator suite confirmed general understanding that the Mediterranean ecosystems have been notably degraded for several decades. Results and conclusions from this descriptive synthesis are compared with other comparisons of more complex, model-derived indicators. Even in upwelling and comparable systems, the simple data-based indicators are useful in synthesizing information on the status of an ecosystem, in particular on the ecosystem effects of fishing, to provide an ecological diagnosis at the ecosystem level, to be used in decision-making. Indicators of recent ecosystem state and trends over time are needed to assess the effects of fishing, but more indicators measuring biodiversity attributes and environmental change would complement the suite, providing fuller assessment of the status of upwelling and comparable ecosystems.

Keywords: comparative approach, indicators, marine ecosystems, reference levels, thresholds

Within the IndiSeas WG, the evaluation of exploited marine ecosystems has several steps, from simple binary categorization of ecosystems to a more-complex attempt to rank them and to evaluate their status using decision-tree analyses. With the intention of communicating scientific knowledge to the public and stakeholders, focus is on evaluating and comparing the status of exploited marine ecosystems using a set of six ecological indicators and a simple and transparent graphic representation of ecosystem state (pie charts). A question that arose was whether it was acceptable to compare different types of marine ecosystems using a generic set of indicators. To this end, an attempt is made to provide reference levels to which ecosystems can be objectively compared. Unacceptable thresholds for each indicator are determined based on ecological expertise derived from a questionnaire distributed to a group of scientific experts. Analysis of the questionnaires revealed no significant difference in the thresholds provided for different ecosystem types, suggesting that it was reasonable to compare states directly across different types of ecosystem using the set of indicators selected.

Keywords: comparative approach, ecological indicators, ecosystem effects of fishing, exploited marine ecosystems, IndiSeas

Background is provided to the selection of ecological indicators by the IndiSeas Working Group, and the methodology adopted for analysis and comparison of indicators across exploited marine ecosystems is documented. The selected indicators are presented, how they are calculated is explained, and the philosophy behind the comparative approach is given. The combination of selected indicators is intended to reflect different dynamics, tracking processes that display differential responses to fishing, and is meant to provide a complementary means of assessing marine ecosystem trends and states. IndiSeas relied on inputs and insights provided by the local experts from participating ecosystems, helping to understand state and trend indicators and to disentangle the effect of other potential ecosystem drivers, such as climate variability. This project showed that the use of simple and available indicators under an ecosystem approach can achieve a real, wide-reaching evaluation of marine ecosystem status caused by fishing. This is important because the socio-economics of areas where fishing activities develop differs significantly around the globe, and in many countries, insufficient data are available for complex and exhaustive analyses

We present an overview of the plankton studies conducted during the last 25 years in the epipelagic offshore waters of the Mediterranean Sea. This quasi-enclosed sea is characterized by a rich and complex physical dynamics with distinctive traits, especially in regard to the thermohaline circulation. Recent investigations have basically confirmed the long-recognised oligotrophic nature of this sea, which increases along both the west-east and the north-south directions. Nutrient availability is low, especially for phosphorous (N:P up to 60), though this limitation may be buffered by inputs from highly populated coasts and from the atmosphere. Phytoplankton biomass, as chl a, generally displays low values (less than 0.2 μg chl a l−1) over large areas, with a modest late winter increase. A large bloom (up to 3 μg l−1) is observed throughout the late winter and spring exclusively in the NW area. Relatively high biomass values are recorded in fronts and cyclonic gyres. A deep chlorophyll maximum is a permanent feature for the whole basin, except during the late winter mixing. It is found at increasingly greater depths ranging from 30 m in the Alboran Sea to 120 m in the easternmost Levantine basin. Primary production reveals a west-east decreasing trend and ranges between 59 and 150 g C m−2 y−1 (in situ measurements). Overall, the basin is largely dominated by small autotrophs, microheterotrophs and egg-carrying copepod species. The microorganisms (phytoplankton, viruses, bacteria, flagellates and ciliates) and zooplankton components reveal a considerable diversity and variability over spatial and temporal scales, although the latter is poorly studied. Examples are the wide diversity of dinoflagellates and coccolithophores, the multifarious role of diatoms or picoeukaryotes, and the distinct seasonal or spatial patterns of the species-rich copepod genera or families which dominate the basin. Major dissimilarities between western and eastern basins have been highlighted in species composition of phytoplankton and mesozooplankton, but also in the heterotrophic microbial components and in their relationships. Superimposed to these longitudinal differences, a pronounced biological heterogeneity is also observed in areas hosting deep convection, fronts, cyclonic and anti-cyclonic gyres or eddies. In such areas, the intermittent nutrient enrichment promotes a switching between a small-sized microbial community and diatom-dominated populations. A classical food web readily substitutes the microbial food web in these cases. These switches, likely occurring within a continuum of trophic pathways, may greatly increase the flux towards higher trophic levels, in spite of the apparent heterotrophy. Basically, the microbial system seems to be both bottom-up and top-down controlled. A \"multivorous web\" is shown by the great variety of feeding modes and preferences and by the significant and simultaneous grazing impact on phytoplankton and ciliates by mesozooplankton.

Keywords: Mytilus galloprovincialis, Propranolol, Acetaminophen, Feeding rate, Biochemical responses

Environmental risk assessments of human pharmaceuticals and other ‘emerging contaminants’ should integrate both population-relevant endpoints and biomarkers of potential modes of action in a range of species. Adult Mytilus galloprovincialis were exposed to the beta-adrenergic receptor blocker propranolol or to the anti-inflammatory drug acetaminophen (paracetamol), both commonly used therapeutic drugs present in aquatic ecosystems. Mussels were exposed under semi-static conditions for 10 days to either acetaminophen (CAS number 103-90-2; mean measured concentrations 23 and 403 µg/L) or propranolol hydrochloride (CAS number 318-98-9; mean measured propranolol concentrations 11 and 147 µg/L) at 15 ± 1 °C sea water. Feeding rate was assessed as an indicator of general toxicity. For propranolol, the 10-day no-observed effect concentration (feeding rateNOEC) and lowest observed effect concentration (feeding rateLOEC) were 11 and 147 µg/L, respectively. For acetaminophen, feeding rate was increased at both 23 and 403 µg/L, suggesting a 10-day feeding rateNOEC of 403 µg/L. Primarily, phase I carboxylesterase (CbE), phase II glutathione S-transferase (GST) and the anti-oxidant catalase activities were evaluated in digestive gland. Gill GST and acetylcholinesterase (AChE) activities were also measured. Lipid peroxidation (LPO) levels were measured in both tissues to assess oxidative stress. Some enzymatic activities in liver were also reduced after propranolol exposure whilst acetaminophen enhanced them (CbE p < 0.05). Acetaminophen exposure significantly increased hepatic LPO levels and inhibited AChE activity in gill (10-day NOEC and LOEC of 23 and 403 µg/L, respectively), whereas propranolol (11 µg/L) enhanced gill GST.

Keywords: Antioxidant enzymes; Xenobiotic metabolism; Ecological parameters; Marine fish; NW Mediterranean

A suite of hepatic biomarkers currently used in pollution monitoring were measured in eighteen common fish species, comprising five orders, eleven families of teleosts and two elasmobranchs. The sampling was carried out seasonally in front of the Barcelona coast (NW Mediterranean) during 2007. The hepatic enzymes considered were the activities of catalase, glutathione reductase, ethoxyresorufin O-deethylase, carboxylesterase and glutathione S-transferase. As markers at higher levels of biological organization, feeding preferences (on benthic, suprabenthic or zooplanktonic species), swimming capability, stomach fullness and trophic level were considered. Significant species differences were found among all the biochemical parameters analysed, although no relationships among the biomarkers themselves were evidenced. In general enzymatic activities were much higher in teleosts than in elasmobranchs, and in perciforms than in gadiforms. Seasonality was observed in some species with higher activities usually corresponding to the winter period. No site related differences were observed in the two selected sites, which differ over a small pollution gradient. A multivariate canonical Correspondence analysis (CCA) was performed on shelf and slope species separately to relate biochemical markers with ecological variables. CCA revealed that for shelf species, EROD was positively related to benthos feeding as well as trophic level, while on the slope the clearest association was between suprabenthos feeders and trophic level. Our present results, including seasonality, slightly differ from former observations (Solé et al., 2009a) and reveal a more significant role of the ecological variables in controlling biomarkers expression in fish from the shelf.

Keywords: Cholinesterases; Lipid peroxidation; Ecological parameters; Marine fish; NW Mediterranean

Muscular cholinesterase activities, as potential markers of neurotoxic exposure, and lipid peroxidation levels, indicative of oxidative stress damage, both currently used in early-warning pollution monitoring, were characterised in eighteen fish species of ecologic and/or economic importance. These species comprise five orders and eleven families of teleosts and two species of elasmobranchs, feed using different strategies (benthic, epibenthic, endobenthic and pelagic), belong to different trophic levels and express different swimming behaviour. Their habitat ranges from 50 to 60 m (shallow or continental shelf) and 600 to 850 m (middle continental slope). Sampling took place in front of the Barcelona coast (NW Mediterranean) during four seasonal cruises in 2007. In the summer sampling, another site potentially exposed to a different pollution load (Vilanova) was included for comparison. Species, seasonal and site differences were tested and discussed in relation to chemical analysis of the local sediment, systematic position, habitat depth, feeding strategy, trophic level and swimming activity. Greater inter species differences rather than seasonal or site trends were seen in accordance to little pollution fluctuations. Higher cholinesterase activities were recorded in suprabenthos feeders, regardless of depth habitat, whereas LP levels were similar in all species except for the shark Scyliorhinus canicula in which they were consistently elevated. This study confirms and broadens former observations carried out with a more reduced number of fish species (Solé et al., 2008a).

Keywords: Extinction; Diversification; Recovery; Mean field model; Fossil record

Biotic recoveries following mass extinctions are characterized by a complex set of dynamics, including the rebuilding of whole ecologies from low-diversity assemblages of survivors and opportunistic species. Three broad classes of diversity dynamics during recovery have been suggested: an immediate linear response, a logistic recovery, and a simple positive feedback pattern of species interaction. Here we present a simple model of recovery which generates these three scenarios via differences in the extent of species interactions, thus capturing the dynamical logic of the recovery pattern. The model results indicate that the lag time to biotic recovery increases significantly as biotic interactions become more important in the recovery process.

Retrieval of sea surface salinity from SMOS radiometer measurements is a challenging task performed by using forward model algorithms in an iterative convergence scheme. The commission phase for the SMOS Level 2 ocean salinity processor has been successfully completed, and the algorithms have been partially verified. Salinity has been retrieved, and priorities determined for future improvements in the retrieval algorithms.We describe how the SMOS Level 2 Ocean Salinity processor can be used, and characteristics of the output products, together with advice on product use. Some preliminary results confirming the existence of mid-latitude shallow fresh layers are also presented.

Keywords: Musks Fragrances Final effluent Estuary Coast Plymouth Devon UK

Synthetic musks are ubiquitous contaminants in the environment. Compartmental distributions (dissolved, suspended particle associated and sedimentary) of the compounds throughout an axial estuarine transect and in coastal waters are reported. High concentrations of Galaxolide (HHCB) and Tonalide (AHTN) (987-2098 ng/L and 55-159 ng/L, respectively) were encountered in final effluent samples from sewage treatment plants (STPs) discharging into the Tamar and Plym Estuaries (UK), with lower concentrations of Celestolide (ADBI) (4-13 ng/L), Phantolide (AHMI) (6-9 ng/L), musk xylene (MX) (4-7 ng/L) and musk ketone (MK) (18-30 ng/L). Rapid dilution from the outfalls is demonstrated with resulting concentrations of HHCB spanning from 5 to 30 ng/L and those for AHTN from 3 to 15 ng/L.The other musks were generally not detected in the estuarine and coastal waters. The suspended particulate matter (SPM) and sedimentary profiles and compositions (HHCB:AHTN ratios) generally reflect the distribution in the water column with highest concentrations adjacent to sewage outfalls.

The European Space Agency\'s Soil Moisture and Ocean Salinity (SMOS) satellite was launched on November, 2, 2009 from the Russian cosmodrome of Plesetsk. Its objective is to globally and regularly collect measurements of Sea Surface Salinity (SSS). To do that, a pioneering instrument has been developed: the Microwave Imaging Radiometer by Aperture Synthesis (MI-RAS), the rst space-borne, 2-D interferometric radiometer ever built; it operates at L-band, with a central frequency of 1.4135 GHz, and consists of 69 antennas arranged in a Y shape array. MIRAS\' output are brightness temperature maps, from which SSS can be derived through an iterative algorithm, and using auxiliary information. For each overpass of the satel-lite an SSS map is produced, with an estimated accuracy of 1 psu (rmse). According to the Global Ocean Data Assimilation Experiment (GODAE) the mission requirement is instead specied as 0.1 psu after averaging in a 10-day and 2º x 2º spatio-temporal boxes. In previuos works ((Sabia et al., 2010), or more extensively in Dr. Sabia\'s Ph.D. thesis (Sabia, 2008)) the main error sources in retrieving SSS from SMOS measurements were determined as: 1. Scene-dependent bias in the simulated measurements, 2. L-band forward modeling denition, 3. Radiometric sensitivity and accuracy, 4. Constraints in the cost function, and 5. Spatio-temporal averaging. This Ph.D. thesis, is an attempt of reducing part of the aforementioned errors (the relative to the one-overpass SSS (1 - 4)) by a more sophisticated data processing. Firstly, quasi-realistic brightness temperatures have been simulated using the SMOS End-to-end Performance Simulator (SEPS) in its full mode and an ocean model, as provider for geophysical parameters. Using this data set the External Brightness Temperature Calibration technique has been tested to mitigate the scene-dependent bias, while the error introduced by inaccuracies in the L-band forward models has been accounted for by the application of the External Sea Surface Salinity Calibration. Apart from simulated brightness temperatures, both External Brightness Temperature Calibration and External Sea Surface Salinity Calibration have been tested using real synthetic-aperture brightness temperatures, collected by the Helsinki University of Technology HUT-2D radiometer during the SMOS Calibration and Valdation Rehearsal Campaign in August 2007 and on one week of data (in Dual polarization mode) acquired by the SMOS satellite between march 3 and 9, 2010. Finally, a study of the cost function used to derive SSS has been performed: The correlation between measurement mists has been estimated and the efect of including it in the processing have been assessed. As an outcome of a 3-month internship at the Laboratoire LOCEAN in Paris, a theoretical review of the eect of the rain on the very top SSS vertical prole has been carried out and is presented as Appendix.

Keywords: Microwave radiometry 2-D radiometer L-band Sea surface salinity (SSS) Soil moisture and ocean salinity (SMOS)

The interest of the scientific community in global climate has been constantly increasing in the last years. Much effort has been devoted to better understand the water cycle and its role in global climate regulation. This is one of the objectives of the European Space Agency (ESA) Soil Moisture and Ocean Salinity (SMOS) mission, approved in May 1999 and successfully launched in November 2nd 2009. Collecting brightness temperature measurements by means of a new type of instrument, a synthetic aperture radiometer operating at L-Band (MIRAS: Microwave Imaging Radiometer by Aperture Synthesis), the SMOS mission will provide regular and global maps of sea surface salinity (SSS) and soil moisture (SM), two key parameters to describe the water cycle. Synthetic aperture brightness temperatures have been simulated since the early 90s, during the MIRAS technological studies, and both SSS and SM retrievals have been tested with simulated data first, and later with real data to assess and improve the instrument performance. Nevertheless, except for the processing of the data collected by the SMOSillo (MIRAS Demonstrator) on June 20th, 2006, Duffo et al. (2007) and Camps et al. (2008b), these outcomes have never been validated using sea surface brightness temperatures coming from a real synthetic aperture radiometer. The aim of this study is thus to test some of the techniques proposed in previous years to improve the SSS retrieval, in particular only Level 2 techniques (i.e. converting calibrated and geo-located brightness temperature into SSS maps) will be investigated. To do so, brightness temperatures resulting from the SMOS Salinity Demonstrator Campaign held in August 2007 will be used. In that campaign the Helsinki University of Technology-2 Dimensional (HUT-2D) radiometer flown over both over land and sea. The part of the campaign conducted over the sea consisted of two series of flights over a very fresh water plume characterized by a strong SSS gradient (from 0 to 4 psu) in the Gulf of Finland. In-situ auxiliary data was collected simultaneously with the radiometer measurements. The positive outcomes in these very challenging conditions (due to the very low brightness temperature sensitivity to SSS, the lack of accurate models of the sea water dielectric constant at low SSS (Klein & Swift (1977)), and the weak radiometric sensitivity of the HUT-2D radiometer) demonstrate the importance of data pre- and post-processing to improve the results. Removing both brightness temperature biases and salinity retrieval biases and further averaging of the results, permits estimating SSS with an rms error on the order of 1 psu, which is comparable to the SMOS Level 2 expected accuracy

Soil Moisture and Ocean Salinity (SMOS) mission is the second of European Space Agency’s (ESA) Living Planet Programme Earth Explorer Opportunity Missions. SMOS’s objective is to provide global and frequent Soil Moisture and Sea Surface Salinity maps. The single payload embarked on SMOS is the Microwave Imaging Radiometer by Aperture Synthesis (MIRAS), it is a 2D interferometric radiometer operating at the protected L-band with a nominal frequency of 1413.5 MHz. Since SMOS is the first 2D interferometric radiometers put in orbit so far, the characterization of the interferometrically measured brightness temperatures is an attractive topic for the scientific community. This study is focused on the estimation of the systematic antenna-based pattern in the measured brightness temperatures. Two improvements to the currently used method (Ocean Target Transformation) are proposed: · The elimination of the use of any forward model in the estimation of the bias. · The homogenization of the geophysical parameters distribution within the SMOS Field of View. Ocean Target Transformation is introduced in section 2, the proposed model-free methodology is described in section 3, while the effect of homogenizing the geophysical parameters distribution inside the FOV is assessed in section 4. The main conclusions are presented in section 5.

Outcrops of old strata at the shelf edge resulting from erosive gravity‐driven flows have been globally described on continental margins. The reexposure of old strata allows for the reintroduction of aged organic carbon (OC), sequestered in marine sediments for thousands of years, into the modern carbon cycle. This pool of reworked material represents an additional source of 14C‐depleted organic carbon supplied to the ocean, in parallel with the weathering of fossil organic carbon delivered by rivers from land. To understand the dynamics and implications of this reexposure at the shelf edge, a biogeochemical study was carried out in the Gulf of Lions (Mediterranean Sea) where erosive processes, driven by shelf dense water cascading, are currently shaping the seafloor at the canyon heads. Mooring lines equipped with sediment traps and current meters were deployed during the cascading season in the southwestern canyon heads, whereas sediment cores were collected along the sediment dispersal system from the prodelta regions down to the canyon heads. Evidence from grain‐size, X‐radiographs and 210Pb activity indicate the presence in the upper slope of a shelly‐coarse surface stratum overlying a consolidated deposit. This erosive discontinuity was interpreted as being a result of dense water cascading that is able to generate sufficient shear stress at the canyon heads to mobilize the coarse surface layer, eroding the basal strata. As a result, a pool of aged organic carbon (Δ14C = −944.5 ± 24.7‰; mean age 23,650 ± 3,321 ybp) outcrops at the modern seafloor and is reexposed to the contemporary carbon cycle. This basal deposit was found to have relatively high terrigenous organic carbon (lignin = 1.48 ± 0.14 mg/100 mg OC), suggesting that this material was deposited during the last low sea‐level stand. A few sediment trap samples showed anomalously depleted radiocarbon concentrations (Δ14C = −704.4 ± 62.5‰) relative to inner shelf (Δ14C = −293.4 ± 134.0‰), mid‐shelf (Δ14C = −366.6 ± 51.1‰), and outer shelf (Δ14C = −384 ± 47.8‰) surface sediments. Therefore, although the major source of particulate material during the cascading season is resuspended shelf deposits, there is evidence that this aged pool of organic carbon can be eroded and laterally advected downslope.

In the Gulf of Lions (GoL), dense water overflowing off the shelf occurs seasonally and represents the main mechanism affecting the shelf-slope exchange of particulate organic matter (OM). Most of the dense water export takes place in the south-western GoL and in particular through Cap de Creus (CdC) submarine canyon. Here, benthic instruments were deployed to collect down-canyon particulate fluxes whereas surface sediments were taken after the cascading event along the sediment dispersal system on the shelf, in CdC canyon and in the nearby Lacaze-Duthiers (LD) canyon. The chemical composition of the suspended material and surface sediments were investigated using several proxies including organic and inorganic carbon, total nitrogen, biogenic silica, δ13C, Δ14C, and alkaline CuO oxidation products. Thermohaline anomalies and high current speed events were measured in CdC canyon since December 2004 until mid-April 2005 indicating a marked off-shelf export of dense water trough the canyon. During the cascading, mud and relatively coarse shelf and upper canyon sediments were the major component of the mass flux. Conversely, advection of fine material via nepheloid layers dominated down-slope fluxes during pre- and post-cascading. The resulting change in grain-size affected the flux of mineral-bound terrigenous OC, indicating that the down-canyon transport of land-derived OM did not occur as bulk but rather its composition is driven by sediment sorting associated with different transport mechanisms. Both surface sediments and sediment trap samples indicated that CdC canyon is well connected to the GoL terrigenous dispersal system. Conversely, our results suggest an overall limited influence of land-derived OM in LD canyon. In spite of the reduced fluvial nutrient supply, a significant pulsed input of modern marine OM was observed in April 2005 at the end of the cascading period. Both intense mixing and lack of strong water column stratification likely played a key role allowing for both diffusion of nutrients-rich waters into the euphotic zone and efficient vertical sink of marine OC. On its way toward the seafloor, this fresh pool of OC interacted with the dense plume overflowing off the shelf, becoming part of the material laterally advected to the slope.

Keywords: Krill larvae - Copepod prey - PCR - Quantitative PCR

The usefulness of a molecular approach based on polymerase chain reaction (PCR) was investigated to identify and quantify the feeding of larval krill on zooplankton organisms in the Lazarev Sea during winter in 2006. Different primers and probes of dominant copepod species (Oithona sp., Ctenocalanus citer, copepodid stages of Metridia gerlachei and Calanoides acutus), co-occurring with larval krill under sea ice during winter, were developed for quantitative PCR (qPCR) and their species specificity was tested on target and non-target species. The qPCR results showed that larval krill were exclusively feeding on Oithona sp. This result was confirmed by microscopic analysis of stomach and gut contents of larvae from the same stations.

Keywords: ecopath; food-web model; network analysis; fisheries; pelagic environment; ecosystem structure; Greece; Mediterranean Sea; 40°0′–41°0′ N, 23°8′–26°0′ E

A mass-balance trophic model was built to describe the food-web traits of the North Aegean Sea (Strymonikos Gulf and Thracian Sea, Greece, Eastern Mediterranean) during the mid-2000s and to explore the impacts of fishing. This is the first food-web model representing the Aegean Sea, and results were presented and discussed in comparison to other previous ecosystems modelled from the western and the central areas of the basin (South Catalan and North-Central Adriatic Seas). Forty functional groups were defined, covering the entire trophic spectrum from lower to higher trophic levels. Emphasis was placed on commercial invertebrates and fish. The potential ecological role of the invasive ctenophore, Mnemiopsis leidyi, and several vulnerable groups (e.g., dolphins) was also explored. Results confirmed the spatial productivity patterns known for the Mediterranean Sea showing, for example, that the total biomass is highest in N.C. Adriatic and lowest in N. Aegean Sea. Accordingly, food-web flows and several ecosystem indicators like the mean transfer efficiency were influenced by these patterns. Nevertheless, all three systems shared some common features evidencing similarities of Mediterranean Sea ecosystems such as dominance of the pelagic fraction in terms of flows and strong benthic–pelagic coupling of zooplankton and benthic invertebrates through detritus. The importance of detritus highlighted the role of the microbial food-web, which was indirectly considered through detritus dynamics. Ciliates, mesozooplankton and several benthic invertebrate groups were shown as important elements of the ecosystem linking primary producers and detritus with higher trophic levels in the N. Aegean Sea. Adult anchovy was shown as the most important fish group in terms of production, consumption and overall effect on the rest of the ecological groups in the model, in line with results from the Western Mediterranean Sea. The five fishing fleets considered (both artisanal and industrial) had high impacts on vulnerable species and numerous targeted groups given the multispecies nature of the fisheries in the N. Aegean Sea. Several exploitation indices highlighted that the N. Aegean Sea ecosystem was highly exploited and unlikely to be sustainably fished, similarly to other Mediterranean marine ecosystems.

Keywords: ecology, morphometry, otolith, Aphanopus carbo, Aphanopus intermedius, teleosts

The sagittal otolith and eye diameter of two sympatric species of the genus Aphanopus, A. carbo and A. intermedius, from North Atlantic waters were investigated. The study objectives were to find morphometric variables of otoliths to identify the two species and relate ecomorphological characters of otolith and eye diameter to the depth distribution of each species. The otoliths of the two species are very similar, although significant differences in shape, otolith height and weight and the sulcus acusticus area were detected. The ratio between eye diameter and cephalic length (ED:CL ratio) was also significantly different. In both analyses A. carbo obtained higher values, which suggests that A. carbo and A. intermedius live in different spatial niches, and that A. carbo inhabits deeper waters. The ratio between the sulcus and otolith areas (S:O) was low compared to other fish species, which suggests that the hearing capacity of Aphanopus spp. is adapted to low frequency sound. This adaptation may be related to the oceanographic conditions in which these species live, and in particular to the characteristics of sound transmission in the “SOFAR channel”.

Keywords: mixotrophy, Dinobryon, bacterivory

We report the presence and abundance of Dinobryon faculiferum (Chrysophyta) in NW Mediterranean coastal waters, as well as the first estimations of the grazing impact of this mixotrophic species on bacteria. In June 2006, D. faculiferum was detected at an abundance of 37 cell mL–1 (1.2% of total protistan abundance). By grazing with cell-specific rates of 7.8 bacteria cell h–1, this single species explained 4.5% of the total bacterial grazing losses.

We present new 3D seismic and well data from the Ebro Margin, NW Mediterranean Sea, to shed new light on the processes that formed the Messinian Erosion Surfaces (MES) of the Valencia Trough (Mediterranean Sea). We combine these data with backstripping techniques to provide a minimum estimate of the Messinian sea level fall in the EBRO Margin, as well as coupled isostasy and river incision and transport modeling to offer new constraints on the evolution of the adjacent subaerial Ebro Basin. Four major seismic units are identified on the Cenozoic Ebro Margin, based on the seismic data, including two major prograding megasequences that are separated by a major unconfirmity: the MES. The 3D seismic data provide an unprecedented view of the MES and display characteristic features of subaerial incision, including a drainage network with tributaries of at least five different orders, terraces and meandering rivers. The Messinian landscape presents a characteristic stepped-like profile that allows the margin to be subdivided in three different regions roughly parallel to the coastline. No major tectonic control exists on the boundaries between these regions. The boundary between the two most distal regions marks the location of a relatively stable base level, and this is used in backstripping analysis to estimate the magnitude of sea level drop associated with the Messinian Salinity Crisis on the Ebro Margin. The MES on the Ebro Margin is dominated by a major fluvial system, that we identify here as the Messinian Ebro River. The 3D seismic data, onshore geology and modeling results indicate that the Ebro River drained the Ebro Basin well in advance of the Messinian.

Keywords: Submarine landslides • pore pressure • basin modeling • slope instability • scientific drilling

The Ursa Basin, at ~1,000 m depth on the Gulf of Mexico continental slope, contains numerous Mass Transport Deposits (MTDs) of Pleistocene to Holocene age. IODP Expedition 308 drilled three sites through several of these MTDs and encompassing sediments. Logs, sedimentological and geotechnical data were collected at these sites and are used in this study for input to basin numerical models. The objective of this investigation was to understand how sedimentation history, margin architecture and sediment properties couple to control pore pressure build-up and slope instability at Ursa. Measurements of porosity and stress state indicate that fluid overpressure is similar at the different sites (in the range of 0.5–0.7) despite elevated differences in sedimentation rates. Modeling results indicate that this results from pore pressure being transferred from regions of higher to lower overburden along an underlying more permeable unit: the Blue Unit. Overpressure started to develop at ~53 ka, which induced a significant decrease in FoS from 45ka, especially where overburden is lower.

Keywords: Western Mediterranean; Climate change; Monitoring systems; Time series; Trend detection

The deep waters in the Western Mediterranean (> 600 m) are the result of mixing between the two water masses above it (Atlantic Water, 0–200 m and Levantine Intermediate Water, 200–600 m) and heat and buoyancy losses in late winter. Deep waters in the Western Mediterranean have undergone a continuous warming during the second half of the twentieth century and initially it was hypothesized that this had been caused by the warming of the contributing water masses, very likely linked to global warming. Nevertheless, no clear signals of warming have been detected in the intermediate layers and no warming trends were detected in the upper layer before the 1980s. This fact suggested that the cause of deep water warming could be linked to river damming and the consequent salinity increase, instead of to an increase of the heat absorbed by the upper ocean, as in other parts of the world ocean. In this work we use the data base MEDATLAS and data from more recent monitoring programs to construct the longest temperature and salinity time series ever analysed in the Western Mediterranean (1900 to 2008). These time series show that both the upper and intermediate layers have warmed throughout the twentieth century. Long term and decadal variability in the upper layer correlate with surface air temperature in the northern hemisphere and heat absorbed by the upper North Atlantic Ocean, suggesting that the time series analysed in this work reflect the present heat absorption of the oceans in the context of global warming. The present data set highlights the importance of monitoring programs and provides a proxy for the study of climate change.

Keywords: backscatter , calibration , geophysical signal processing , oceanographic techniques , remote sensing by radar , wind

The Advanced Scatterometer (ASCAT) onboard the Metop-A satellite became operational shortly after launch in 2006, and an absolute calibration using three transponders was achieved in November 2008. In this paper, we describe how the CMOD5.n ocean backscatter geophysical model function (GMF), which was derived using data from previous scatterometers onboard the European Remote Sensing 1 and 2 satellites (ERS-1 and ERS-2), was used to derive backscatter bias correction factors. The purpose is to remove the bias between ASCAT backscatter data and the CMOD5.n GMF output which allows these data to be used in place of ERS data in existing wind processing algorithms. The ASCAT Wind Data Processor, developed at the Royal Netherlands Meteorological Institute (KNMI), applies the bias correction factors to ASCAT data and uses CMOD5.n to retrieve wind vectors in order to produce an operational wind product. This resulted in a stable and high-quality ASCAT wind product since February 2007. We validate this product by comparing it to the European Centre for Medium-range Weather Forecasts (ECMWF) winds and buoy measurements. The bias correction factors indicate that ASCAT data and the GMF differ by roughly 0.3 dB below 55 ? and up to 0.8 dB above 55 ?. A possible explanation lies in CMOD5.n which has been poorly validated in this incidence angle regime. Validation of ASCAT data using the ocean calibration method confirms this result and also indicates that bias-corrected data are everywhere within 0.3 dB of CMOD5.n. The wind product validation shows an rms error of 1.3 m ?s-1 in wind speed and 16 ? in wind direction when compared to ECMWF winds. This is better than the results achieved using ERS scatterometer data. Against buoy winds, we find an rms error wind component error of approximately 1.8 m ?s-1 . These results show that the ASCAT wind product is of high quality and satisfies its wind component accuracy requirement of - - 2 m ?s-1.

Keywords: Biomineral • mesocrystal • crystallography • calcite • EBSD • hierarchical organization • modularity • Corallium rubrum • complex shape

Biominerals can achieve complex shapes as aggregates of crystalline building blocks. In the red coral skeleton, we observe that these building blocks are arranged into eight hierarchical levels of similarly (but not identically) oriented modules. The modules in each hierarchical level assemble into larger units that comprise the next higher level of the hierarchy, and consist themselves of smaller, oriented modules. EBSD and TEM studies show that the degree of crystallographic misorientation between the building blocks decreases with decreasing module size. We observe this organization down to a few nanometers. Thus, the transition from imperfect crystallographic order at millimeter scale to nearly perfect single crystalline domains at nanometer scale is progressive. The concept of \"mesocrystal\" involves the three-dimensional crystallographic organization of nanoparticles into a highly ordered mesostructure. We add to this concept the notion of \"multilevel modularity.\" This modularity has potential implications for the origin of complex biomineral shapes in nature. A multilevel modular organization with small intermodular misorientations combines a simple construction scheme, ruled by crystallographic laws, with the possibility of complex shapes. If the observations we have made on red coral extend to other biominerals, long-range crystallographic order and interfaces at all scales may be key to how some biominerals achieve complex shapes adapted to the environment in which they grow.

Microbial mats are stratified microbial communities composed by highly inter-related populations and therefore are frequently chosen as model systems to study diversity and ecophysiological strategies. The present study describes an integrated approach to analyze microbial quinones and intact polar lipids (IPLs) in microbial mats within layers as thin as 500 µm by liquid chromatography–tandem mass spectrometry. Quinone profiles revealed important depth-related differences in community composition in two mat systems. The higher abundance of ubiquinones, compared to menaquinones, reflected the clear predominance of microorganisms belonging to aerobic α-, β-, and γ-Proteobacteria in Ebro delta estuarine mats. Hypersaline photosynthetic Camargue mats (France) showed a predominance of menaquinone-9 at the top of the mat, which is consistent with an important contribution of facultative aerobic or anaerobic bacteria in its photic zone. Quinone indices also indicated a higher diversity of non-phototrophs and a more anaerobic character in the hypersaline mats. Besides, the dissimilarity index suggested that the samples were greatly influenced by a depth-related redox state gradient. In the analysis of IPLs, there was a predominance of phosphatidylglycerols and sulfoquinovosyldiacylglycerols, the latter being an abundant biomarker of Cyanobacteria. This combined approach based on quinone and IPL analysis has proven to be a useful method to establish differences in the microbial diversity and redox state of highly structure microbial mat systems at a fine-scale level.

Keywords: polyhydroxyalkanoates * heterotroph * cyanobacteria * microbial mat

Photosynthetic microbial mats are sources of microbial diversity and physiological strategies that reflect the physical and metabolic interactions between their resident species. This study focused on the diversity and activity of polyhydroxyalkanoate-producing and -degrading bacteria and their close partnership with cyanobacteria in an estuarine and a hypersaline microbial mat. The aerobic heterotrophic population was characterized on the basis of lipid biomarkers (respiratory quinones, sphingoid bases), polyhydroxyalkanoate determination, biochemical analysis of the isolates, and interaction assays. Most of the polyhydroxyalkanoate-producing isolates obtained from an estuarine mat belonged to the Halomonas and Labrenzia genera, while species of Sphingomonas and Bacillus were more prevalent in the hypersaline mat. Besides, the characterization of heterotrophic bacteria coisolated with filamentous cyanobacteria after selection suggested a specific association between them and diversification of the heterotrophic partner belonging to the Halomonas genus. Preliminary experiments suggested that syntrophic associations between strains of the Pseudoalteromonas and Halomonas genera explain the dynamics of polyhydroxyalkanoate accumulation in some microbial mats. These metabolic interactions and the diversity of the bacteria that participate in them are most likely supported by the strong mutual dependence of the partners.

The processes involved in the vertical splitting of vortices in geophysical dipoles, rotating and stably stratified, are investigated using a three-dimensional numerical model under the f-plane and Boussinesq approximations. Vertical splitting in asymmetric dipoles is possible when the vortices have a similar amount of potential vorticity but significantly differ in vertical extent. One representative case of vertical splitting is analyzed, and it is found that prior to the splitting there is a shearing period characterized by vertical unalignment and loss of horizontal axisymmetrization. The splitting starts when the upper and lower parts of the deep vortex independently experience vertical alignment and horizontal axisymmetrization. Vertical splitting also involves vortex horizontal splitting in the intermediate layers, which might explain the vertical asymmetry found in some isolated subsurface vortices in the ocean interior.

Keywords: Zooplankton; Fish; Mesopelagic; Bathypelagic; DNA barcode; Diversity; Atlantic Ocean; Sargasso Sea

The deep-sea zooplankton assemblage is hypothesized to have high species diversity, with low abundances of each species. However, even rare species may have huge population sizes and play a critical role in the dynamics of deep-sea environments. The Census of Marine Zooplankton (CMarZ) study sought to accurately assess zooplankton diversity in the mesopelagic and bathypelagic zones of the subtropical/tropical of the northwest and eastern sections of the Atlantic Ocean using integrated morphological and molecular analysis of large-volume samples to depths of 5,000 m. The field surveys in April 2006 and November 2007 included scientists and students associated with the CMarZ. The cruise field work entailed at-sea analysis of samples and identification of specimens by expert taxonomists, with at-sea DNA sequencing to determine a barcode (i.e., a short DNA sequence for species recognition) for selected species. Environmental data and zooplankton samples were collected with 1-m2 and 10-m2 opening/closing MOCNESS (0–1000 m and 1000–5000 m, respectively), and with either a 0.25-m2 MOCNESS or a 0.5-m2 Multi-net above 1000 m. More than 500 species were identified and more than 1000 specimens placed in a queue for barcoding on each cruise; several hundred species were barcoded at sea. For several taxonomic groups, a significant fraction of the region’s known species were collected and identified. For example, in the northwest Atlantic 93 of 140 known ostracod species for the Atlantic Ocean were collected, 6 undescribed species were found, and the first DNA barcode for a planktonic ostracod was obtained. The deployment of trawls with fine-mesh nets to sample large volumes at great depths for small zooplankton confirmed that there is considerable species diversity at depth, with more species yet to be discovered.

Attempts to gauge the biological impacts of climate change have typically focussed on the lower levels of organization (individuals to populations), rather than considering more complex multi-species systems, such as entire ecological networks (food webs, mutualistic and host–parasitoid networks). We evaluate the possibility that a few principal drivers underpin network-level responses to climate change, and that these drivers can be studied to develop a more coherent theoretical framework than is currently provided by phenomenological approaches. For instance, warming will elevate individual ectotherm metabolic rates, and direct and indirect effects of changes in atmospheric conditions are expected to alter the stoichiometry of interactions between primary consumers and basal resources; these effects are general and pervasive, and will permeate through the entire networks that they affect. In addition, changes in the density and viscosity of aqueous media could alter interactions among very small organisms and disrupt the pycnoclines that currently compartmentalize many aquatic networks in time and space. We identify a range of approaches and potential model systems that are particularly well suited to network-level studies within the context of climate change. We also highlight potentially fruitful areas of research with a view to improving our predictive power regarding climate change impacts on networks. We focus throughout on mechanistic approaches rooted in first principles that demonstrate potential for application across a wide range of taxa and systems.

Keywords: * global warming * carbon sequestration * carbon cycle * metabolic theory * gross primary production * ecosystem respiration

The carbon cycle modulates climate change, via the regulation of atmospheric CO2, and it represents one of the most important services provided by ecosystems. However, considerable uncertainties remain concerning potential feedback between the biota and the climate. In particular, it is unclear how global warming will affect the metabolic balance between the photosynthetic fixation and respiratory release of CO2 at the ecosystem scale. Here, we present a combination of experimental field data from freshwater mesocosms, and theoretical predictions derived from the metabolic theory of ecology to investigate whether warming will alter the capacity of ecosystems to absorb CO2. Our manipulative experiment simulated the temperature increases predicted for the end of the century and revealed that ecosystem respiration increased at a faster rate than primary production, reducing carbon sequestration by 13 per cent. These results confirmed our theoretical predictions based on the differential activation energies of these two processes. Using only the activation energies for whole ecosystem photosynthesis and respiration we provide a theoretical prediction that accurately quantified the precise magnitude of the reduction in carbon sequestration observed experimentally. We suggest the combination of whole-ecosystem manipulative experiments and ecological theory is one of the most promising and fruitful research areas to predict the impacts of climate change on key ecosystem services.

The carbon cycle modulates climate change via the regulation of atmospheric CO2, and represents one of the most important ecosystem services of value to humans. However, considerable uncertainties remain concerning potential feedbacks between the biota and the climate. We developed theoretical models derived from the metabolic theory of ecology (MTE), and tested them in an ecosystem-level manipulative experiment in freshwater mesocosms. The year-long experiment simulated a warming scenario (A1B; [IPCC, 2007]) expected by the end of the century. The key components of the carbon cycle – that is gross primary production (GPP), ecosystem respiration (ER) and CH4 efflux (ME) – measured in our experiment were all strongly related to temperature. Their temperature dependence was typically constrained by the average activation energy of their particular metabolic pathway, and as predicted by our models, this increased progressively for GPP, ER and ME. Warming of 4 °C decreased the sequestration of CO2 by 13%, increased the fraction of primary production effluxing as methane by 20% and the fraction of ER as methane by 9%, in line with the offset in their respective activation energies. Because methane has 21 times the greenhouse gas radiative potential of CO2, these results suggest aquatic ecosystems could drive a previously unknown positive feedback between warming and the carbon cycle. We then used a series of global data compilations of measurements of rates of primary production and respiration to better understand the temperature dependence of the carbon cycle in other aquatic ecosystems and to compare them with data from terrestrial systems. Our experimental results were mirrored by our global data compilations, with the effective activation energy for marine and freshwater primary production identical to GPP measured in our experiment. Similarly, the temperature dependences of respiration in estuaries, lakes and the ocean were indistinguishable from that of ER in our experiment. Finally, our study suggests that the temperature dependence of primary production and respiration in aquatic ecosystems might differ from those in terrestrial ecosystems, and this could be crucial in predicting the future response of the carbon cycle in these different systems to global warming.

Keywords: Biological invasions; Marine aliens; Biogeography; Biodiversity; Mediterranean Sea.

The state-of-art on alien species in the Mediterranean Sea is presented, making distinctions among the four subregions defined in the EU Marine Strategy Framework Directive: (i) the Western Mediterranean Sea (WMED); (ii) the Central Mediterranean Sea (CMED); (iii) the Adriatic Sea (ADRIA); and (iv) the Eastern Mediterranean Sea (EMED). The updated checklist (December 2010) of marine alien species within each subregion, along with their acclimatization status and origin, is provided. A total of 955 alien species is known in the Mediterranean, the vast majority of them having being introduced in the EMED (718), less in the WMED (328) and CMED (267) and least in the Adriatic (171). Of these, 535 species (56%) are established in at least one area. Despite the collective effort of experts who attempted in this work, the number of introduced species remains probably underestimated. Excluding microalgae, for which knowledge is still insufficient, aliens have increased the total species richness of the Mediterranean Sea by 5.9%. This figure should not be directly read as an indication of higher biodiversity, as spreading of so many aliens within the basin is possibly causing biotic homogenization. Thermophilic species, i.e. Indo-Pacific, Indian Ocean, Red Sea, Tropical Atlantic, Tropical Pacific, and circum(sub)tropical, account for 88.4% of the introduced species in the EMED, 72.8% in the CMED, 59.3% in the WMED and 56.1% in the Adriatic. Cold water species, i.e. circumboreal, N Atlantic, and N Pacific, make up a small percentage of the introduced species, ranging between 4.2% and 21.6% and being more numerous in the Adriatic and less so in the EMED. Species that are classified as invasive or potentially invasive are 134 in the whole of the Mediterranean: 108 are present in the EMED, 76 in the CMED, 53 in the Adriatic and 64 in the WMED. The WMED hosts most invasive macrophytes, whereas the EMED has the lion’s share in polychaetes, crustaceans, molluscs and fish.