Departament de recursos
marins renovables

Keywords: Dioxin exposure; Bioaccumulation; Chemical markers; Food.

Aquacultured fish gilthead seabream (Sparusaurata), previously exposed to low levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) trough the diet for a 13 months period, were fed on a clean feed for another 22 months. Gilthead seabream is a protandrous hermaphrodite species and this “decontamination” period coincided with the stages of sex differentiation, maturity and reproduction of the fish. PCDD/F levels in the fish tissues (i.e. muscle, liver, perivisceral fat and gonads), expressed in pg WHO-TEQ g−1 fresh weight, showed a general decreasing trend during the “decontamination” period. However, this general trend varied among tissues and was also dependent on sex and lipid contents. Toxicological effects affecting fish behaviour and hepatic marker responses were also evaluated. The results pointed out that exposure to PCDD/Fs did not have an impact on fish development and reproduction, since the proportion of sexes found after the sex reversal process was within the normal range described for this species. In addition, long-term exposure to low PCDD/F levels did not significantly affect the response of most of the biochemical markers considered. On the contrary, some of them (e.g. EROD activity) showed variations in their responses during the sex differentiation process and onwards. Finally, the hepatic AhR mRNA levels increased during dioxin exposure but they returned to values typical for non-exposed fish after the “decontamination” period.

Keywords: Lophogaster spinosus, Lophogastrida, North–eastern Atlantic, Gulf of Cadiz..

Occurrence of Lophogaster spinosus Ortmann, 1906 (Crustacea, Lophogastrida) in the Gulf of Cadiz (NE Atlantic).— The occurrence of the lophogastrid crustacean Lophogaster spinosus is reported for the Gulf of Cadiz waters, in the North–East Atlantic. This is the first report of the species for the Iberian Atlantic region. Samples were collected by demersal trawling during a fisheries research survey performed in March 2008. A total of four specimens were collected at three sampling sites. Depths of occurrence ranged between 363 and 548 m.

Keywords: OBSEA; cabled observatories; multidisciplinary observation; EMSO ESONET; remote ecosystem monitoring; automated video image analysis; fish community; activity rhythms.

A suitable sampling technology to identify species and to estimate population dynamics based on individual counts at different temporal levels in relation to habitat variations is increasingly important for fishery management and biodiversity studies. In the past two decades, as interest in exploring the oceans for valuable resources and in protecting these resources from overexploitation have grown, the number of cabled (permanent) submarine multiparametric platforms with video stations has increased. Prior to the development of seafloor observatories, the majority of autonomous stations were battery powered and stored data locally. The recently installed low-cost, multiparametric, expandable, cabled coastal Seafloor Observatory (OBSEA), located 4 km off of Vilanova i la Gertrú, Barcelona, at a depth of 20 m, is directly connected to a ground station by a telecommunication cable; thus, it is not affected by the limitations associated with previous observation technologies. OBSEA is part of the European Multidisciplinary Seafloor Observatory (EMSO) infrastructure, and its activities are included among the Network of Excellence of the European Seas Observatory NETwork (ESONET). OBSEA enables remote, long-term, and continuous surveys of the local ecosystem by acquiring synchronous multiparametric habitat data and bio-data with the following sensors: Conductivity-Temperature-Depth (CTD) sensors for salinity, temperature, and pressure; Acoustic Doppler Current Profilers (ADCP) for current speed and direction, including a turbidity meter and a fluorometer (for the determination of chlorophyll concentration); a hydrophone; a seismometer; and finally, a video camera for automated image analysis in relation to species classification and tracking. Images can be monitored in real time, and all data can be stored for future studies. In this article, the various components of OBSEA are described, including its hardware (the sensors and the network of marine and land nodes), software (data acquisition, transmission, processing, and storage), and multiparametric measurement (habitat and bio-data time series) capabilities. A one-month multiparametric survey of habitat parameters was conducted during 2009 and 2010 to demonstrate these functions. An automated video image analysis protocol was also developed for fish counting in the water column, a method that can be used with cabled coastal observatories working with still images. Finally, bio-data time series were coupled with data from other oceanographic sensors to demonstrate the utility of OBSEA in studies of ecosystem dynamics.

Ocean waters deeper than 200 m cover 70% of the Earth\'s surface. Light intensity gets progressively weaker with increasing depth and internal tides or inertial currents may be the only remaining zeitgebers regulating biorhythms in deep-sea decapods. Benthopelagic coupling, exemplified by vertically moving shrimps within the water column, may also act as a source of indirect synchronisation to the day-night cycle for species living in permanently dark areas. At the same time, seasonal rhythms in growth and reproduction may be an exogenous response to spring-summer changes in upper layer productivity (via phytoplankton) or, alternatively, may be provoked by the synchronisation mediated by an endogenous controlling mechanism (via melatonin). In our review, we will focus on the behavioural rhythms of crustacean decapods inhabiting depths where the sun light is absent. Potential scenarios for future research on deep-sea decapod behaviour are suggested by new in situ observation technologies. Permanent video observatories are, to date, one of the most important tools for marine chronobiology in terms of species recognition and animals\' movement tracking.

Keywords: cabled observatory; automated image analysis; squat lobster (Munida quadrispina); bacterial mat (Beggiatoa spp.); Scale-Invariant Feature Transform (SIFT); Fourier Descriptors (FD).

The development and deployment of sensors for undersea cabled observatories is presently biased toward the measurement of habitat variables, while sensor technologies for biological community characterization through species identification and individual counting are less common. The VENUS cabled multisensory network (Vancouver Island, Canada) deploys seafloor camera systems at several sites. Our objective in this study was to implement new automated image analysis protocols for the recognition and counting of benthic decapods (i.e., the galatheid squat lobster, Munida quadrispina), as well as for the evaluation of changes in bacterial mat coverage (i.e., Beggiatoa spp.), using a camera deployed in Saanich Inlet (103 m depth). For the counting of Munida we remotely acquired 100 digital photos at hourly intervals from 2 to 6 December 2009. In the case of bacterial mat coverage estimation, images were taken from 2 to 8 December 2009 at the same time frequency. The automated image analysis protocols for both study cases were created in MatLab 7.1. Automation for Munida counting incorporated the combination of both filtering and background correction (Median- and Top-Hat Filters) with Euclidean Distances (ED) on Red-Green-Blue (RGB) channels. The Scale-Invariant Feature Transform (SIFT) features and Fourier Descriptors (FD) of tracked objects were then extracted. Animal classifications were carried out with the tools of morphometric multivariate statistic (i.e., Partial Least Square Discriminant Analysis; PLSDA) on Mean RGB (RGBv) value for each object and Fourier Descriptors (RGBv+FD) matrices plus SIFT and ED. The SIFT approach returned the better results. Higher percentages of images were correctly classified and lower misclassification errors (an animal is present but not detected) occurred. In contrast, RGBv+FD and ED resulted in a high incidence of records being generated for non-present animals. Bacterial mat coverage was estimated in terms of Percent Coverage and Fractal Dimension. A constant Region of Interest (ROI) was defined and background extraction by a Gaussian Blurring Filter was performed. Image subtraction within ROI was followed by the sum of the RGB channels matrices. Percent Coverage was calculated on the resulting image. Fractal Dimension was estimated using the box-counting method. The images were then resized to a dimension in pixels equal to a power of 2, allowing subdivision into sub-multiple quadrants. In comparisons of manual and automated Percent Coverage and Fractal Dimension estimates, the former showed an overestimation tendency for both parameters. The primary limitations on the automatic analysis of benthic images were habitat variations in sediment texture and water column turbidity. The application of filters for background corrections is a required preliminary step for the efficient recognition of animals and bacterial mat patches.

Keywords: RFID; automated video imaging; Nephrops norvegicus; controller; USB communication; marine species; laboratory; burrow emergence; activity rhythms.

Radio frequency identification (RFID) devices are currently used to quantify several traits of animal behaviour with potential applications for the study of marine organisms. To date, behavioural studies with marine organisms are rare because of the technical difficulty of propagating radio waves within the saltwater medium. We present a novel RFID tracking system to study the burrowing behaviour of a valuable fishery resource, the Norway lobster (Nephrops norvegicus L.). The system consists of a network of six controllers, each handling a group of seven antennas. That network was placed below a microcosm tank that recreated important features typical of Nephrops’ grounds, such as the presence of multiple burrows. The animals carried a passive transponder attached to their telson, operating at 13.56 MHz. The tracking system was implemented to concurrently report the behaviour of up to three individuals, in terms of their travelled distances in a specified unit of time and their preferential positioning within the antenna network. To do so, the controllers worked in parallel to send the antenna data to a computer via a USB connection. The tracking accuracy of the system was evaluated by concurrently recording the animals’ behaviour with automated video imaging. During the two experiments, each lasting approximately one week, two different groups of three animals each showed a variable burrow occupancy and a nocturnal displacement under a standard photoperiod regime (12 h light:12 h dark), measured using the RFID method. Similar results were obtained with the video imaging. Our implemented RFID system was therefore capable of efficiently tracking the tested organisms and has a good potential for use on a wide variety of other marine organisms of commercial, aquaculture, and ecological interest.

There is currently relatively little information on how marine organisms process and analyze sound, making assessments about the impacts of artificial sound sources in the marine environment difficult. However, such assessments have become a priority because noise is now considered as a source of pollution that increasingly affects the natural balance of the marine ecosystems. We present the first morphological and ultrastructural evidence of massive acoustic trauma, not compatible with life, in four cephalopod species subjected to low-frequency controlled-exposure experiments. Exposure to low-frequency sounds resulted in permanent and substantial alterations of the sensory hair cells of the statocysts, the structures responsible for the animals\' sense of balance and position. These results indicate a need for further environmental regulation of human activities that introduce high-intensity, low-frequency sounds in the world\'s oceans.

Keywords: Growth; Size at maturity; Nephrops norvegicus; Population structure; Portuguese coast.

The aim of the study was to analyse the size, growth and size at maturity of Nephrops norvegicus in two areas off the Portuguese coast. Samples were collected between September 2006 and January 2007. A total of 2081 individuals ranging between 25 and 88 mm carapace length were collected, measured and sexed. The estimated growth parameters were L∞ = 88.33 mm CL, k = 0.38 years−1 for males and L∞ = 64.45 mm CL, k = 0.38 years−1 for females in the northern area, and L∞ = 94.86 mm CL, k = 0.41 years−1 for males and L∞ = 69.20 mm CL, k = 0.44 years−1 for females in the central area. Size at maturity was 50.7 mm CL in the northern area and 46.9 mm CL in the central area.

One of the expected effects of global change is increased variability in the abundance and distribution of living organisms, but information at the appropriate temporal and geographical scales is often lacking to observe these patterns. Here we use local knowledge as an alternative information source to study some emerging changes in Mediterranean fish diversity. A pilot study of thirty-two fishermen was conducted in 2009 from four Mediterranean locations along a south-north gradient. Semi-quantitative survey information on changes in species abundance was recorded by year and suggests that 59 fish species belonging to 35 families have experienced changes in their abundance. We distinguished species that increased from species that decreased or fluctuated. Multivariate analysis revealed significant differences between these three groups of species, as well as significant variation between the study locations. A trend for thermophilic taxa to increase was recorded at all the study locations. The Carangidae and the Sphyraenidae families typically were found to increase over time, while Scombridae and Clupeidae were generally identified as decreasing and Fistularidae and Scaridae appeared to fluctuate in abundance. Our initial findings strongly suggest the northward expansion of termophilic species whose occurrence in the northern Mediterranean has only been noted previously by occasional records in the scientific literature.

Keywords: pelagic observatory; oceanographic buoy; multisensor coordinated monitoring; PAR; operational oceanography; submarine canyons; numerical multiparametric modelling;.

The new pelagic Operational Observatory of the Catalan Sea (OOCS) for the coordinated multisensor measurement of atmospheric and oceanographic conditions has been recently installed (2009) in the Catalan Sea (41°39\'N, 2°54\'E; Western Mediterranean) and continuously operated (with minor maintenance gaps) until today. This multiparametric platform is moored at 192 m depth, 9.3 km off Blanes harbour (Girona, Spain). It is composed of a buoy holding atmospheric sensors and a set of oceanographic sensors measuring the water conditions over the upper 100 m depth. The station is located close to the head of the Blanes submarine canyon where an important multispecies pelagic and demersal fishery gives the station ecological and economic relevance. The OOCS provides important records on atmospheric and oceanographic conditions, the latter through the measurement of hydrological and biogeochemical parameters, at depths with a time resolution never attained before for this area of the Mediterranean. Twenty four moored sensors and probes operating in a coordinated fashion provide important data on Essential Ocean Variables (EOVs; UNESCO) such as temperature, salinity, pressure, dissolved oxygen, chlorophyll fluorescence, and turbidity. In comparison with other pelagic observatories presently operating in other world areas, OOCS also measures photosynthetic available radiation (PAR) from above the sea surface and at different depths in the upper 50 m. Data are recorded each 30 min and transmitted in real-time to a ground station via GPRS. This time series is published and automatically updated at the frequency of data collection on the official OOCS website (http://www.ceab.csic.es/~oceans). Under development are embedded automated routines for the in situ data treatment and assimilation into numerical models, in order to provide a reliable local marine processing forecast. In this work, our goal is to detail the OOCS multisensor architecture in relation to the coordinated capability for the remote, continuous and prolonged monitoring of atmospheric and oceanographic conditions, including data communication and storage. Accordingly, time series of measurements for a number of biological parameters will be presented for the summer months of 2011. Marine hindcast outputs from the numerical models implemented for simulating the conditions over the study area are shown. The strong changes of atmospheric conditions recorded in the last years over the area have altered the marine conditions of living organisms, but the dimension of the impact remains unclear. The OOCS multisensor coordinated monitoring has been specifically designed to address this issue, thus contributing to better understand the present environmental fluctuations and to provide a sound basis for a more accurate marine forecast system.

Keywords: Vasa; Helicases; Primordial germ cells; Sex differentiation; Gonadal development; Gametogenesis; European sea bass.

Vasa is a protein expressed mainly in germ cells and conserved across taxa. However, sex-related differences and environmental influences on vasa expression have not been documented. This study characterized the cDNA of a vasa homolog in the European sea bass, Dicentrarchuslabrax (sb-vasa), a gonochoristic fish with temperature influences on gonadogenesis. The 1911 bp open reading frame predicted a 637-amino acid protein with the eight conserved domains typical of Vasa proteins. Comparisons of the deduced amino acid sequence with those of other vertebrates and invertebrates revealed the highest homology (68–85%) with those of other teleosts. An updated tree with the full-length sequences for Vasa proteins in 66 species belonging to six different phyla was constructed, establishing the evolutionary relationships of Vasa amino acid sequences. European sea bass vasa was highly expressed in gonads with little or no expression in other tissues. Real time RT-PCR quantification of the temporal expression of sb-vasa from early development throughout sex differentiation showed that mRNA levels were high in unfertilized eggs, decreased during larval development and increased again during the period of germ cell proliferation. Rearing of fish at high temperature resulted in further increased sb-vasa levels, most likely reflecting temperature effects on both somatic and gonadal growth. Differences in expression were also found well before sex differentiation and persisted until the end of the first year, with higher levels present in females. These differences in expression demonstrate the implication of vasa during the initial stages of fish sex differentiation and gametogenesis and suggest that, through its helicase activity, it might be implicated in the translational regulation of mRNAs involved in the specification and differentiation of gonadal-specific cell types.

Keywords: Climate change · Marine ecosystems · Catalan Sea · Mediterranean Sea · Time series.

The Catalan Sea, located between the eastern Iberian coast and the Balearic Islands, is a representative portion of the western Mediterranean basin and provides a valuable case study for climate change effects on Mediterranean ecosystems. Global warming is reflected regionally by a rise in sea level over the last century, an increase in surface temperature of around 1.1°C in the last 35 yr, a progressive salinisation of intermediate and deep waters and a strengthening of the stratification. A likely scenario of what we can expect in the Mediterranean Sea is a considerable decrease in rainfall and wind, warmer surface waters and a prolonged stratification period. The effects on Mediterranean ecosystems are evident in: (1) a meridionalisation of the algal, invertebrate and vertebrate species, which favours the more thermophilic species over the temperate species; (2) mass mortality events of sessile invertebrates of the coralligenous communities owing to anomalous warm waters during the period when food is scarce; (3) increases in the smallest phytoplankton due to the prolongation of the water stratification period; (4) proliferation of gelatinous carnivores, including jellyfish, due to the temperature rise and the lack of rainfall; (5) a faster acidification of seawater, compared with the global oceans, accompanied by a decrease in the capacity to absorb atmospheric CO2. In order to anticipate and mitigate these predicted changes, we recommend investing in research and observation, conserving areas that serve as indicators of climate change and reducing other anthropogenic pressures such as habitat destruction, overfishing or pollution, which may act synergistically to accelerate these changes.

Keywords: Anguilla anguilla; Elliptic Fourier analysis; Habitat related changes; Otolith shape; Size–shape relationshipe.

Otolith morphology is an efficient tool for the discrimination of fish stocks, populations and species when comparative genetic data are not available. Currently, the relationship between environmental factors and otolith shape is poorly characterized for the European eel (Anguilla anguilla), a highly migratory catadromous species constituting a single, randomly mating stock. The present study analyses the differences in otolith morphology between three Mediterranean eel local stocks from different environmental contexts (i.e. two brackish lagoons and one river). The relationship between otolith shape and otolith size was studied by means of Elliptic Fourier analysis and multivariate statistics. Otolith profile was digitally acquired and Cartesian coordinates were extracted. Partial Least Square (PLS) analysis pointed to continuous allometric growth in size and shape in otoliths from all three sites. In the three environments, shape variations occurred during growth as indicated by the presence of a significant and positive relationship between otolith size and the first PLS latent vector (i.e. which bears most of the information regarding otolith outline). Differences between smaller and larger sized otoliths were investigated using PLS Discriminant Analysis (PLSDA) and cluster analysis. Results indicate that otolith shape is highly uniform at smaller than at larger sizes. These shape differences apparently overlap the initial differentiation of the small otolith outlines acquired by eels during the growing phase as elvers in the marine environment. Data were discussed considering that the physical and chemical habitat variability in brackish lagoons and river could underlie a marked change in otolith shape during the animals\' growth.

Keywords: temporal changes; lipid biomarkers; fatty acids; deep-sea; Boreomysis arctica; Nematoscelis megalops; benthic boundary layer; suprabenthos; life histories.

Two species of benthopelagic deep-water crustaceans, the suprabenthic mysid Boreomysis arctica and the bathypelagic euphausiid Nematoscelis megalops were analysed in their lipidic composition, with especial emphasis on fatty acids, from specimens obtained in the north-west of Mallorca (Balearic Islands, western Mediterranean) at depths ranging between 650 and 780 m. Temporal shifts were studied seasonally, based on five cruises performed in August and November 2003, and February, April and June 2004, using a Macer-GIROQ suprabenthic sledge (0.5 mm mesh size). Evidences of omnivorous and carnivorous feeding habits were found for both species derived from their fatty acid and other lipid profiles. Boreomysis arctica showed a more varied fatty acid profile than N. megalops. This suggests that B. arctica feeds on a wider range of food sources and is a more opportunistic feeder. The high proportions of 16:1(n-7), 20:5(n-3) and 22:6(n-3) fatty acids in both species suggests a link between surface primary production and deep slope habitats, while markers such as 18:1(n-9) and the 20:1(n-9) and 22:1(n-11) fatty alcohols indicate a predatory activity, likely on calanoids. These components may arrive both via phytodetritus deposition to the seabed and by migratory movements of prey consumed by B. arctica and N. megalops close to the sea bottom. Seasonal changes in the total lipids and fatty acid composition of both species are related to the seasonal dynamics in their food sources, coupled with changes in the physiological or developmental stage of individuals. The proportion of total lipids and polyunsaturated fatty acids in the two species may be related to the different life histories of B. arctica and N. megalops. The mysid has direct development of embryos within brood pouches, so eggs with large amount of vitelum are generated and gonad is well developed. By contrast, the meso-bathypelagic euphausiids generate planktotrophic larvae, with a high number of free developmental larvae stages (from nauplius to Furcilia/Calyptopis), and eggs with poor storage of lipid compounds compared with B. arctica embryos.

Keywords: Deep Sea Levantine Intermediate Water (LIW) Physical oceanography Aristaeomorpha foliacea Dissolved oxygen Metabolic acclimatation Species extinction Loss of diversity.

We compiled long-term data (from commercial landings and scientific surveys) on the density (D) and the depth distribution of the deep-living shrimp Aristaeomorpha foliacea in the Balearic Basin (western Mediterranean) from the 1950s to 2010. We analyzed these data in relation to changes in temperature (T) and salinity (S) of the intermediate water column, where the species inhabits. A. foliacea showed the highest densities in the 1950s–1960s in the northern sector of the Balearic Basin off the central coasts of Catalonia, ca. 0.6–20.7 ind/ha, and to the north of Mallorca, ca. 7.5–43 ind/ha. Later, densitiesN1 ind/ha were only found close to Eivissa Channel at the south side of the Balearic Basin: 1.9–11.4 ind/ha in 1992, 2001 and 2005. In the northern Balearic Basin, A. foliacea has almost disappeared since the 1970s. In the same period A. foliacea showed significant deepening (r2=0.90) of its population Center of Gravity (CoG) from the 1950s–60s (CoG=466 m) to 1995–2002 (CoG=538 m) and then stabilized during 2003–2010 (CoG=535m). Temperature of the Levantine Intermediate Water (LIW) core (at ca. 400 m depth) off the central coasts of Catalonia progressively increased from 12.95 °C in 1957 to 13.31 °C in 1977, reaching 13.44 °C and 13.41 °C in 1998 and 2007 respectively. Salinity showed a similar increase from 38.40 psu in 1957 to 38.43 psu in 1977, then reaching 38.55 psu in 1998 and 38.56 psu in 2007. Estimated D of A. foliacea decreased significantly (Spearman ρ) when the T and S at the LIW core increased (pb10−6), as did T and S at the optimum depth of A. foliacea (pb0.001). Multiple Linear regression (MLR) models related the decrease of A. foliacea D with increasing T at LIW (up to 55% of explained variance, depending upon the variables included in the MLR model). The optimum depth of A. foliacea was always deeper than the LIW core, with the depth difference between the CoG and the LIW core increasing from 80.6 m in 1957 to 138.1–153.7 m in the 1990s–2000s. Thus, the optimum habitat of the species was never directly linked to LIW conditions (maxima of T and S) as previously thought. We discuss possible physiological and trophic effects that could explain the local extinction of A. foliacea in the northern Balearic Basin due to changes of T and S in its habitat, associated with reduced O2 concentration at the LIW core

Keywords: Suprabenthos; Western Mediterranean; Diversity; Production.

The composition of suprabenthic crustacean assemblages, their diversity, production (P) and production/biomass (P/B) ratios, were analyzed at species level along two transects situated to the north (N) and south (S) of Mallorca (Balearic Islands, western Mediterranean) at depths between 134 m and 760 m, based on a ca. bi-monthly sampling performed between August 2003 and June 2004. Differences with depth and season in assemblage composition and diversity were analyzed as a function of the contrasting environmental features (e.g. water mass dynamics) of the two areas. We identified 187 species (18 decapods, 5 euphausiids, 16 mysids, 76 gammaridean amphipods, 13 hyperiids, 1 caprellid, 21 isopods and 37 cumaceans). Substantial mesoscale variability in the deep-sea suprabenthic assemblages coupled with diversity trends between the N and S transects were found. Seasonality was the most important gradient influencing the dynamics of suprabenthos over the upper (350 m) and middle (650–750 m) slope in the N area. Conversely, the S area appeared to be more stable temporally with depth as the main gradient inducing assemblage differences. Different depth-related patterns were observed both for diversity and P/B. To the north diversity was very low at the shelf-break, increasing on the upper-slope (H′ > 3.00) and then decreasing again on the middle-slope. To the south diversity increased smoothly downward, reaching the highest values on the middle-slope. Regarding productivity, P/B was highest at intermediate depths to the north (over ca. 450–500 m), while to the south highest P/Bs were found deeper (over ca. 600–650 m). The higher P/B at intermediate depths found along N are likely due to higher % of organic matter (OM) in sediments, a product of oceanographic frontal systems. In particular, P/B was higher along N among omnivores and detritus feeders (e.g. Andaniexis mimonectes, Lepechinella manco and combined cumaceans), coupled to enriched OM in sediments, while along S mesoplanktonic carnivores (Rhachotropis spp.) had higher P/Bs. We conclude that on the north slope the influence of frontal systems and more active flow dynamics of different water masses (WIW and LIW) increases natural disturbance in the area, increasing productivity and diversity of suprabenthic peracarids in the Benthic Boundary Layer. Also, species showed a displacement of their average distributions (their Centres of Gravity, CoG) to shallower depths along N, which is another indicator of more favorable habitat conditions for suprabenthos in the 400–500 m range at N.

Greatly increased retention of flow in Nile River reservoirs was initiated in 1964, after completion of the Aswan High Dam, which induced important oceanographic changes in the Mediterranean Sea, including deep waters (below a depth of 150 m). Based on an analysis of data series starting in the 1940s/1950s, the giant red shrimp Aristaeomorpha foliacea has become locally extinct off of the Catalonian coasts (and elsewhere in the northwestern Mediterranean) at depths of 400–900 m, with a simultaneous and significant drop in the catches of red shrimp, Aristeus antennatus, in the second half of the 1960s. The extinction and sharp decline of deep-shrimp populations off Catalonian coast (at ca. 3200 km westwards from Nile Delta) followed the 1964 drop in Nile discharge with a delay of ca. 3–5 yrs (breakpoint analysis applied to data series). The breakpoints detected in the second half of 1960s both in Nile runoff and shrimps’ abundance were independent of climatic events in the study area (e.g. changes in NAO) and occurred before the increase in fishing effort off Catalonian coasts (breakpoint in 1973–1974). The Levantine Intermediate Water (LIW), inhabited by A. foliacea in the western Basin, had significant temperature (T) and salinity (S) increases in the 1950–1970 period, and Nile damming has contributed about 45% of the total S increase of Western Mediterranean deep-water masses from the 1960s to the late 1990s (Skliris and Lascaratos, 2004). This had to increase, for instance, LIW salinity at its formation site in the eastern Mediterranean. Nile damming was probably a triggering factor for the extinction/drop in abundance of deep-sea shrimp off Catalonian coasts.

Keywords: Aquaporin 1b; cDNA cloning and characterization; Catfish; cAMP stimulation; Oocyte hydration; Vasotocin; Xenopus assay.

The oocytes of the freshwater catfish Heteropneustes fossilis hydrate during hormone-induced meiotic maturation. To investigate if this process may be mediated by aquaporins (AQPs), as it occurs in marine fish producing highly hydrated eggs, the cloning of ovarian AQPs in catfish was carried out. Using degenerate primers for conserved domains of the major intrinsic protein (MIP) family, and 5′ and 3′end amplification procedures, a full-length cDNA encoding for an AQP1-like protein was isolated. The predicted protein showed the typical six transmembrane domains and two Asn-Pro-Ala (NPA) motifs conserved among the members of the AQP superfamily. Phylogenetic analysis indicated that the catfish AQP clustered with the teleost-specific aquaporin-1b subfamily, and accordingly it was termed HfAqp1b. Heterologous expression in Xenopus laevis oocytes indicated that HfAqp1b encoded for a functional AQP, water permeability being enhanced by cAMP. Site-directed mutagenesis revealed that cAMP induced the translocation of HfAqp1b into the oocyte plasma membrane most likely through the phosphorylation of HfAqp1b Ser227. In adult catfish, hfaqp1b transcripts were detected exclusively in ovary and brain and showed significant seasonal variations; in the ovary, hfaqp1b was maximally expressed during the pre-spawning period, whereas in the brain the highest expression was detected during spawning. In vitro stimulation of isolated catfish ovarian follicles with vasotocin (VT) or human chorionic gonadotropin (hCG), which induce oocyte maturation and hydration, elevated the hfaqp1b transcript levels after 6 or 16 h of incubation, respectively. These results suggest that HfAqp1b may play a role during VT- and hCG-induced oocyte hydration in catfish, and that VT may regulate HfAqp1b at the transcriptional and post-translational level in a manner similar to the vasopressin-dependent mammalian AQP2.

Background Increasing cell membrane permeability to water and cryoprotectants is critical for the successful cryopreservation of cells with large volumes. Artificial expression of water-selective aquaporins or aquaglyceroporins (GLPs), such as mammalian aquaporin-3 (AQP3), enhances cell permeability to water and cryoprotectants, but it is known that AQP3-mediated water and solute permeation is limited and pH dependent. To exploit further the possibilities of using aquaporins in cryobiology, we investigated the functional properties of zebrafish (Danio rerio) GLPs. Results Water, glycerol, propylene glycol and ethylene glycol permeability of zebrafish Aqp3a, -3b, -7, -9a, -9b, -10a and -10b, and human AQP3, was examined. Expression in Xenopus laevis oocytes indicated that the permeability of DrAqp3a and -3b to ethylene glycol was higher than for glycerol or propylene glycol under isotonic conditions, unlike other zebrafish GLPs and human AQP3, which were more permeable to glycerol. In addition, dose-response experiments and radiolabeled ethylene glycol uptake assays suggested that oocytes expressing DrAqp3b were permeated by this cryoprotectant more efficiently than those expressing AQP3. Water and ethylene glycol transport through DrAqp3a and -3b were, however, highest at pH 8.5 and completely abolished at pH 6.0. Point mutations in the DrAqp3b amino acid sequence rendered two constructs, DrAqp3b-T85A showing higher water and ethylene glycol permeability at neutral and alkaline pH, and DrAqp3b-H53A/G54H/T85A, no longer inhibited at acidic pH but less permeable than the wild type. Finally, calculation of permeability coefficients for ethylene glycol under concentration gradients confirmed that the two DrAqp3b mutants were more permeable than wild-type DrAqp3b and/or AQP3 at neutral pH, resulting in a 2.6- to 4-fold increase in the oocyte intracellular concentration of ethylene glycol. Conclusion By single or triple point mutations in the DrAqp3b amino acid sequence, we constructed one mutant with enhanced ethylene glycol permeability and another with reduced pH sensitivity. The DrAqp3b and the two mutant constructs may be useful for application in cryobiology.

Keywords: teleost,aquaporin,oocyte,spermatogenesis,spermatozoa,embryo.

Aquaporinsarebelievedtobeinvolvedinhomeosmoticmechanismsofmarineteleosts.Increasingdatasuggestthatthesemolecularwaterchannelsplaycriticalrolesassociatedwiththeadaptationofgametesandearlyembryostotheexernalspawningenvironment.Inthismini-review,wediscussrecentstudiessuggestingthefunctionofaquaporin-mediatedfluidhomeostasisduringspermatozoaactivationandeggformationinteleosts.Inaddition,weaddressthepotentialroleofwaterchannelsinosmosensingandcellmigrationduringearlyembryonicdevelopment.

Seagrass beds provide important habitat for a wide range of marine species but are threatened by multiple human impacts in coastal waters. Although seagrass communities have been well-studied in the field, a quantification of their food-web structure and functioning, and how these change across space and human impacts has been lacking. Motivated by extensive field surveys and literature information, we analyzed the structural features of food webs associated with Zostera marina across 16 study sites in 3 provinces in Atlantic Canada. Our goals were to (i) quantify differences in food-web structure across local and regional scales and human impacts, (ii) assess the robustness of seagrass webs to simulated species loss, and (iii) compare food-web structure in temperate Atlantic seagrass beds with those of other aquatic ecosystems. We constructed individual food webs for each study site and cumulative webs for each province and the entire region based on presence/absence of species, and calculated 16 structural properties for each web. Our results indicate that food-web structure was similar among low impact sites across regions. With increasing human impacts associated with eutrophication, however, food-web structure show evidence of degradation as indicated by fewer trophic groups, lower maximum trophic level of the highest top predator, fewer trophic links connecting top to basal species, higher fractions of herbivores and intermediate consumers, and higher number of prey per species. These structural changes translate into functional changes with impacted sites being less robust to simulated species loss. Temperate Atlantic seagrass webs are similar to a tropical seagrass web, yet differed from other aquatic webs, suggesting consistent food-web characteristics across seagrass ecosystems in different regions. Our study illustrates that food-web structure and functioning of seagrass habitats change with human impacts and that the spatial scale of food-web analysis is critical for determining results.

Keywords: Cumulative impacts; human threats; marine biodiversity; marine conservation; marine protected areas; Mediterranean Sea.

Aim  A large body of knowledge exists on individual anthropogenic threats that have an impact on marine biodiversity in the Mediterranean Sea, although we know little about how these threats accumulate and interact to affect marine species and ecosystems. In this context, we aimed to identify the main areas where the interaction between marine biodiversity and threats is more pronounced and to assess their spatial overlap with current marine protected areas in the Mediterranean. Location  Mediterranean Sea. Methods  We first identified areas of high biodiversity of marine mammals, marine turtles, seabirds, fishes and commercial or well-documented invertebrates. We mapped potential areas of high threat where multiple threats are occurring simultaneously. Finally we quantified the areas of conservation concern for biodiversity by looking at the spatial overlap between high biodiversity and high cumulative threats, and we assessed the overlap with protected areas. Results  Our results show that areas with high marine biodiversity in the Mediterranean Sea are mainly located along the central and north shores, with lower values in the south-eastern regions. Areas of potential high cumulative threats are widespread in both the western and eastern basins, with fewer areas located in the south-eastern region. The interaction between areas of high biodiversity and threats for invertebrates, fishes and large animals in general (including large fishes, marine mammals, marine turtles and seabirds) is concentrated in the coastal areas of Spain, Gulf of Lions, north-eastern Ligurian Sea, Adriatic Sea, Aegean Sea, south-eastern Turkey and regions surrounding the Nile Delta and north-west African coasts. Areas of concern are larger for marine mammal and seabird species. Main conclusions  These areas may represent good candidates for further research, management and protection activities, since there is only a maximum 2% overlap between existing marine protected areas (which cover 5% of the Mediterranean Sea) and our predicted areas of conservation concern for biodiversity.

Keywords: Image analysis – Shape analysis – Agricultural products – Multivariate statistics.

The appearance of agricultural products deeply conditions their marketing. Appearance is normally evaluated by considering size, shape, form, colour, freshness condition and finally the absence of visual defects. Among these features, the shape plays a crucial role. Description of agricultural product shape is often necessary in research fields for a range of different purposes, including the investigation of shape traits heritability for cultivar descriptions, plant variety or cultivar patents and evaluation of consumer decision performance. This review reports the main applications of shape analysis on agricultural products such as relationships between shape and: (1) genetic; (2) conformity and condition ratios; (3) products characterization; (4) product sorting and finally, (5) clone selection. Shape can be a protagonist of evaluation criteria only if an appreciable level of image shape processing and automation and data are treated with solid multivariate statistic. In this context, image-processing algorithms have been increasingly developed in the last decade in order to objectively measure the external features of agricultural products. Grading and sorting of agricultural products using machine vision in conjunction with pattern recognition techniques offers many advantages over the conventional optical or mechanical sorting devices. With this aims, we propose a new automated shape processing system which could be useful for both scientific and industrial purposes, forming the bases of a common language for the scientific community. We applied such a processing scheme to morphologically discriminate nuts fruit of different species. Operative Matlab codes for shape analysis are reported.

Keywords: Engraulis encrasicolus; late larvae; Northwestern Mediterranean; condition; growth.

The fishery of the European anchovy Engraulis encrasicolus in the Mediterranean needs several ecological approaches to be properly managed. As such, several surveys were carried out to study the ecology of larvae and juveniles of this species, which reproduces during the warmest period of the year (May through September) in the Gulf of Lions. In particular, we studied the late larvae (15 mm total length until metamorphosis), especially as other authors have focused on larvae below that size. Unexpectedly, we also collected anchovy late larvae during the December 2007 survey, whose range in size corresponded to a later spawning period than previously reported. Differences in the nutritional condition of these larvae were assessed by comparing indices of lipid composition and estimating growth rates from otolith measurements to provide information on the probability of survival between the two groups. The analysis of fatty acids, used as tracers of trophic relationships, indicates that these larvae fed mainly on zooplankton. Nutritional conditions of summer and late autumn larvae were very similar. In contrast, growth rates were higher for August larvae, probably due to the different temperatures in the two seasons. Our results are especially relevant in an ecological context where the increasing mean water temperatures in the Western Mediterranean could favor the extension of the anchovy spawning period up to late-Autumn months.

Keywords: Nutritional condition; Morphometrics; Histology; RNA/DNA; Engraulis anchoita.

Nutritional condition of anchovy Engraulis anchoita larvae from Northern Argentinean sea was assessed and compared in three areas characterized by dissimilar oceanographic features (estuarine, mixed and shelf waters). Morphometrical, histological and biochemical (RNA/DNA) indexes were used and larvae were compared through different developmental stages. Multivariate analyses performed on normalized morphometric variables showed that larvae from mixed waters where characterized by higher body depths; variables that indicate a better nutritional condition. Mean histological condition index obtained for larvae at intermediate developmental stages was significantly lower in estuarine waters than those estimated with samples from mixed or shelf waters. Anchovy larvae from the mixed water area showed a higher slope in the log RNA versus log DNA relationship than larvae from the other areas, which indicates that the former were in better condition. Also, standardized RNA/DNA index (RNA/DNAs) resulted slightly better in mixed waters than in shelf area, for larvae at intermediate developmental stages, but due to the high variability of RNA/DNA ratio, no significant differences were found between areas. Finally, using literature equations relating RNA/DNAs, temperature and growth, growth rate and growth performance were estimated. Mean growth performance did not differ between areas and was temperature independent. In conclusion, larval condition was relatively high at all stations, but our results suggested that it was slightly better in frontal areas characterized by water masses with intermediate salinities. We also provide evidence that anchovy larvae might not be food limited in any of the studied areas.

Keywords: suprabenthos; spatial variability; assemblage structure; diversity; stable isotopes; trawl-ban.

Meso-scale spatial variability of coastal suprabenthic communities inhabiting muddy bottoms at 50–80 m depth in three gulfs of northern Sicily (Western Mediterranean) was here investigated. Although similar as concerns the hydrological and oceanographic conditions, the three areas, that encompass a large portion of the continental shelf (135 km), are characterized by different geo-morphological features. In addition, they are subjected to different trawl fishery pressures. The Gulf of Castellammare is a semi-enclosed bay, where the trawling activity has been banned since 1990. The Gulf of Termini Imerese and the Gulf of Sant’Agata are open areas, subjected to high trawl fishing intensity. In terms of density, gammarid amphipods showed differences among the three gulfs; in terms of biomass, cumaceans and amphipods were more abundant in the Gulf of Castellammare than in the other two areas. Multivariate analyses provided evidence for separation of suprabenthic assemblages between the Gulf of Castellammare and the other two gulfs. The Gulf of Castellammare seemed to host the most diversified and stable community according to α- and β-diversity indices. In the same way the low value of δ13C vs. δ15N correlation found in the gulf of Castellammare, which evidences the occurrence of several food sources, supports the idea of a higher stability in the semi-enclosed, trawl-ban area. In the other two areas δ13C vs. δ15N correlations were high, suggesting the existence of a pelagic source sustaining the suprabenthic communities. This is also confirmed by the lower δ13C concentrations found in suprabenthic species. Taking into account the homogeneous oceanographic conditions among gulfs, other factors, such as geo-morphology and trawling pressure should be involved in the observed differences among the three areas in terms of assemblage structure, diversity, and trophodynamics of suprabenthic communities.

Keywords: Benthos; Invertebrates; Stable isotopes; Environmental variables; Western Mediterranean.

The food-web structure of the epibenthic and infaunal invertebrates on the continental slope of the Catalan Sea (Balearic basin, NW Mediterranean) was investigated using carbon and nitrogen stable isotopes on a total of 34 species, and HPLC pigment analyses for three key species. Samples were collected close to Barcelona (NE Iberian Peninsula), between 650 and 800 m depth and between February 2007 and February 2008. Mean δ13C values ranged from −21.0‰ (small Calocaris macandreae and Amphipholis squamata) to −14.5‰ (Sipunculus norvegicus). Values of δ15N ranged from 4.0‰ (A. squamata) to 12.1‰ (Molpadia musculus). The stable isotope ratios of benthic fauna displayed a continuum of values (e.g. δ15N range of 8‰), confirming a wide spectrum of feeding strategies (from active suspension feeders to predators) and complex food webs. According to the available information on diets of benthic fauna, the lowest values were found for surface deposit feeders (small C. macandrae and the two ophiuroids A. squamata and Amphiura chiajei) and active suspension feeders (Abra longicallus and Scalpellum scalpellum) feeding on different sizes of particulate organic matter (POM), among which small particles may exhibit lower δ15N. High annual mean δ15N values were found among sub-surface deposit feeders, exploiting refractory or frequently recycled organic matter that is enriched in δ15N. Carnivorous polychaetes (Nephtys spp., Oenonidae and Polynoidae) and large decapods (Geryon longipes and Paromola cuvieri) also displayed high δ15N values. δ13C ranges were particularly wide among surface deposit feeders (ranging from −21.0‰ to −16.4‰), suggesting exploitation of POM of both terrigenous and oceanic origins. Correlation between δ13C and δ15N was generally weak, indicating multiple carbon sources, likely due to the consumption of different kinds of sinking particles (e.g. marine snow, phytodetritus, etc.), sedimented and frequently recycled POM, together with macrophyte remains. The stronger δ13C–δ15N correlations found in February and April suggest that during the period of water column homogeneization (winter–spring), the benthic community was sustained by phytodetritus inputs originating from the peak of surface primary production in February. Conversely, weaker δ13C–δ15N correlations were observed during the period of water column stratification (beginning in June–July), suggesting that the benthic community in this period was sustained, with a delay of ca. 2/3 months, by multiple carbon sources including continental inputs from river discharge (with the maxima in April–May). Thus both advective and vertical fluxes seem to be food sources for benthos on the Catalonian slope. Pigments in the guts of key species were generally degraded, and only the active suspension feeder A. longicallus ingested fresh chlorophyll during periods of high primary production at the surface (February and April 2007).

Keywords: resource partitioning; stable isotopes; stomach contents; temporal variability.

Resource partitioning in two congeneric sparids, pandora Pagellus erythrinus and axillary seabream Pagellus acarne, was investigated using stomach content analysis integrated with data on stable isotopes (δ15N and δ13C). The study was carried out on coastal muddy bottoms in the Gulf of Castellammare (southern Tyrrhenian Sea, western Mediterranean Sea) in seasons (autumn, November 2004; winter, March 2005; spring, early June 2005), at depths between 50 and 100 m. Stomach content analysis suggested low trophic niche overlap between the two species. Pagellus erythrinus mainly preyed on strictly benthic organisms (polychaetes, brachyuran crabs and benthic crustaceans). Although it consumed benthic prey, P. acarne preferred suprabenthic prey such as peracarid crustaceans from the benthic boundary layer a few metres above the bottom. The two species showed different isotopic values, with P. erythrinus exhibiting higher δ15N and more enriched δ13C than P. acarne, in accordance with its marked benthic behaviour and high predation on carnivore polychaetes. Significant temporal variability in both diet and isotopic values caused trophic differences between the two species. The autumn and winter diet differed from the spring diet and the trophic levels of both species increased from autumn and winter to spring, in accordance with variations in food availability and changes in prey δ15N and δ13C. These temporal variations may be linked to an increase in energy requirements for reproduction, together with the differing availability of preferred prey throughout the year. Significantly, lower δ13C was recorded in fishes collected in winter (March), suggesting the influence of river inputs as a source of particulate organic matter in this zone after the flooding season. In conclusion, these sympatric congeneric fish species displayed clear food partitioning throughout the temporal scale analysed.

Keywords: Macrozooplankton; Micronekton; Stable isotopes; Environmental variables; Western Mediterranean.

Food web structure of the macroplankton/micronekton fauna on the continental slope of the Catalan Sea (Balearic basin, NW Mediterranean) was investigated using carbon and nitrogen stable isotope tracers on a total of 34 taxa. Samples were collected close to Barcelona, Spain, on the middle slope, at a seasonal scale. Mean δ13C values ranged from − 22.1‰ (Salpa maxima) to − 16.9‰ (the mysid Eucopia hanseni). Values of δ15N ranged from 2.5‰ (the hyperiid Vibilia armata) to 9.8‰ (the pelagic polychaete Tomopteris sp.). The stable isotope ratios of this fauna displayed a continuum of values over the δ15N range of 7‰, confirming a wide spectrum of feeding strategies (from filter feeders to predators). High annual mean δ15N values were found among carnivorous large zooplankton and micronekton, including species that prey on gelatinous plankton (i.e. salps, siphonophores), euphausiids, natantian decapod crustaceans and fish (i.e. myctophids and stomiiformes). In agreement with the available information on diets of planktonic taxa, the lowest isotope ratios were found for filter feeders (V. armata, S. maxima, the pteropods Cymbulia peroni and Cavolinia inflexa, ostracods and the thaliacean Pyrosoma atlanticum), all of which feed on particulate organic matter. We found three trophic levels in macroplankton/micronekton food webs based on a 15N-enrichment factor of ~ 2.5‰ per level. The range of δ13C was particularly wide among carnivores (− 20.7‰ to − 16.6‰), suggesting predation on a variety of prey from gelatinous zooplankton (which displayed more depleted δ13C signatures) to small fishes and decapods. Correlation between δ13C–δ15N was generally weak, likely due to the consumption of different kinds of sinking particles (e.g. marine snow, phytodetritus), some constituted of multiply recycled particulate organic matter (POM). However, higher δ13C–δ15N correlations were observed during winter and spring, periods of water column homogenization, suggesting that the planktonic community assimilates pulses of new production from the photic zone (peaking in January–February). Low correlations were observed during periods of water column stratification, particularly in summer, when production is especially low, suggesting that in this period macroplankton–micronekton community rely on sources other than surface primary production such as POM derived from river discharge.

Keywords: Senegalese sole, Solea senegalensis, feeding treatment, starvation, RNA/DNA ratio, critical swimming speed, Ucrit, ontogeny..

Food availability can affect larval survival directly through starvation and indirectly through the effects on larval growth rate, swimming performance and vulnerability to predators. In the present study we evaluate the effects of starvation on growth, nutritional condition and swimming behaviour of the Senegalese sole (Solea senegalensis) throughout ontogeny (8 to 14 days after hatching). Biochemical analysis (RNA/DNA ratios) and behavioural experiments (critical swimming speed, Ucrit) were conducted on larvae reared under 3 feeding treatments: fed ad libitum, deprived of food for 48 hours and deprived of food for 96 hours. Growth was significantly affected by feeding treatment, while only slight decreases in RNA/DNA ratio and swimming performance were registered. Late stage larvae of the three feeding treatments had slower critical speeds than the pre-flexion and flexion stages, which is probably related to the benthic lifestyle acquired by the species at the end of the larval period. These physiological and behavioural changes are in accordance with previous results, which show that flatfish larvae are more resistant to starvation than pelagic species and that they become less active later in development.

Keywords: aquaporin, gene duplication, evolution, neofunctionalization, water transport.

Aquaporins represent a primordial group of transmembrane solvent channels that have been documented throughout the living biota. This facet alone emphasizes the positive selection pressure for proteins associated with intracellular fluid homeostasis. Amongst extant Eukaryota the highest gene copy number can be found in plants and teleosts, a feature that reflects the genomic duplication history in both groups. In this minireview we discuss the discovery, structure, duplication, and diversification of the aquaporin superfamily. We focus on teleosts as the main models, but include data available for other organisms to provide a broader perspective

Keywords: Animal proteomics; Flatfish; Gene expression; Spermatogenesis; Testis.

The Senegalese sole (Solea senegalensis) is a marine flatfish of high economic value and a target species for aquaculture. The efforts to reproduce this species in captivity have been hampered by the fact that farmed males (F1) often show lower sperm production and fertilization capacity than wild-type males (F0). Our knowledge on spermatogenesis is however limited to a few studies. In a previous work, we identified by 2-D DIGE several potential protein markers in testis for the poor reproductive performance of F1 males. Therefore, the objectives of the present study were, first, to investigate changes in genes and proteins expressed in the testis throughout spermatogenesis in F0 males by using a combination of transcriptomic and proteomic approaches and, second, to further compare the testis proteome between late spermatogenic stages of F0 and F1 fish to identify potential indicators of hampered reproductive performance in F1 fish. We identified approximately 400 genes and 49 proteins that are differentially expressed during the progression of spermatogenesis and that participate in processes such as transcriptional activation, the ubiquitin–proteasome system, sperm maturation and motility or cytoskeletal remodeling. Interestingly, a number of these proteins differed in abundance between F0 and F1 fish, pointing toward alterations in cytoskeleton, sperm motility, the ubiquitin–proteasome system and the redox state during spermiogenesis as possible causes for the decreased fertility of F1 fish.

Keywords: Alfacs Bay; Bivalve physiology; In situ experiment; Mussels; Seston.

The feeding behavior of the mussel Mytilus galloprovincialis was investigated in the field on top of a mussel raft in Alfacs Bay, NW Mediterranean Sea. The experiments were performed in November 2006 and February, April and July 2007 using a flow-through filter feeding device. Total particulate matter (TPM), particulate organic matter (POM) and particulate inorganic matter (PIM) were calculated for the bay water, as well as the feces and pseudofeces of the mussels. These were used with the biodeposition method to estimate several feeding-physiological parameters, such as the clearance rate (CR), rejection rate through pseudofeces production (RP), organic ingestion rate (OIR), absorption rate (AR) and absorption efficiency (AE). The results showed that the characteristics of available suspended matter for mussels in terms of particle concentration (TPM: mg/l) and organic content (f defined as POM/TPM) ranged 1.03-2.30. mg/l, and 0.48 to 0.73 respectively throughout the study period. This indicates a rather stable feeding environment of low concentrations of high organic content particles despite the wide range of temperatures recorded (from 10 to 26 °C). However, a characteristic of such a variation pattern of particle suspension (TPM and f) was that short-term variations (in the course of days) covered the whole range of annual variation. Accordingly, physiological parameters characterizing both food acquisition and absorption in mussels were found to respond to short-term variations in food regime. Pseudofeces production in mussels was low (less than 5% in most cases) and they tended to reduce their clearance rate instead of increasing their pseudofeces production in response to rising particle concentration. The absorption efficiency was positively related to the organic content of the seston particles. There was also a positive correlation between clearance rate and absorption efficiency. The reduction of clearance, ingestion and absorption rates obtained in July highlights a negative influence of high water temperatures upon feeding and digestive processes of mussels.

The analysis of 255 bottom trawl samples obtained in annual experimental surveys (2007–2010) along the western Mediterranean shows the existence of five well-defined demersal assemblages that follow a depth distribution: (a) upper shelf assemblages, including two assemblages differentiated by the type of substrate (sand-muddy and terrigenous muddy bottoms); (b) a middle shelf assemblage; (c) an upper slope assemblage; (d) a middle slope assemblage. Faunally, they are dominated by fish (37% of 452 total species), followed by crustaceans (22%), molluscs (17%), echinoderms (9%), and other invertebrates (15%). The assemblages identified showed major alterations on the shelf and shelf edge and less pronounced ones on the upper and middle slope. The average diversity values were more or less high, evidencing the high species richness in the western Mediterranean. The identified assemblages may facilitate future multispecies fisheries management based on an ecosystem approach.

The ChEss project of the Census of Marine Life (2002–2010) helped foster internationally-coordinated studies worldwide focusing on exploration for, and characterization of new deep-sea chemosynthetic ecosystem sites. This work has advanced our understanding of the nature and factors controlling the biogeography and biodiversity of these ecosystems in four geographic locations: the Atlantic Equatorial Belt (AEB), the New Zealand region, the Arctic and Antarctic and the SE Pacific off Chile. In the AEB, major discoveries include hydrothermal seeps on the Costa Rica margin, deepest vents found on the Mid-Cayman Rise and the hottest vents found on the Southern Mid-Atlantic Ridge. It was also shown that the major fracture zones on the MAR do not create barriers for the dispersal but may act as trans-Atlantic conduits for larvae. In New Zealand, investigations of a newly found large cold-seep area suggest that this region may be a new biogeographic province. In the Arctic, the newly discovered sites on the Mohns Ridge (71°N) showed extensive mats of sulfur-oxidisng bacteria, but only one gastropod potentially bears chemosynthetic symbionts, while cold seeps on the Haakon Mossby Mud Volcano (72°N) are dominated by siboglinid worms. In the Antarctic region, the first hydrothermal vents south of the Polar Front were located and biological results indicate that they may represent a new biogeographic province. The recent exploration of the South Pacific region has provided evidence for a sediment hosted hydrothermal source near a methane-rich cold-seep area. Based on our 8 years of investigations of deep-water chemosynthetic ecosystems worldwide, we suggest highest priorities for future research: (i) continued exploration of the deep-ocean ridge-crest; (ii) increased focus on anthropogenic impacts; (iii) concerted effort to coordinate a major investigation of the deep South Pacific Ocean – the largest contiguous habitat for life within Earth\'s biosphere, but also the world\'s least investigated deep-ocean basin.

Keywords: Liocarcinus depurator, Brachyura, Portunidae, juvenile development, Mediterranean.

The early juvenile crab stages (C1 to C5) of the portunid crab Liocarcinus depurator (Linnaeus, 1758) were obtained in the laboratory from megalopae captured from the plankton in the northwest Mediterranean. Morphological development through these stages is described and compared with previous juvenile descriptions and adult morphology. The definitive adult morphology of carapace teeth is only apparent from stage C4. The incision on the lower orbital margin of the carapace and the mesial lobe (“portunid lobe”) of the endopod of the first maxilliped starts to be evident from C3. Stage C5 is already very similar to that of the typical adult crab. Male and female crabs can be distinguished from stage C2 onwards, based on sexual dimorphism in pleopods. The morphology and size of Mediterranean juvenile crabs was compared with the previous description of individuals reared in the laboratory from ovigerous females from British North Atlantic waters.

Keywords: Merluccius merluccius, sex ratio, reproductive cycle, length at first maturity, fecundity..

The reproductive biology of the European hake (Merluccius merluccius, Linnaeus, 1758) was studied on the eastern central Atlantic Moroccan coast from November 2001 to December 2003. The sex ratio was close to 1:1 for the specimens with a total length of less than 45 cm. European hake spawned all year round, though two spawning peaks were recorded with a certain interannual variability: the first and main peak in winter and a secondary intermittent peak in summer. Length at first maturity was estimated as 28.6 cm and 33.8 cm total length for males and females, respectively. These values are closer to Mediterranean than Atlantic hake values. The mean batch fecundity was 299872 eggs ind–1. The relative batch fecundity was estimated as 228 eggs per gram of gutted weight. Batch fecundity increased proportionally with fish length and weight. The batch fecundity of European hake in the Moroccan Atlantic area is higher than that in northern Atlantic and northwestern Mediterranean areas.

Keywords: anti-cyclonic eddy, cross-shelf transport, Leeuwin Current , neritic, larval fish, Myctophidae.

The timing, sources and pathways for incorporation of larval fishes into a developing anti-cyclonic eddy off south-western Australia were investigated. Larval fish assemblages within the study region were structured by location (shelf, eddy and oceanic) and water mass. The larval fish assemblage within the eddy was significantly distinct from that characterizing the surrounding oceanic water. The eddy assemblage, which was comprised largely of larvae of oceanic meso-pelagic fishes (especially Diaphus spp. and Vinciguerria spp.) and less abundant neritic taxa, reflected its Leeuwin Current (LC), shelf and oceanic source waters. The occurrence of neritic taxa in the eddy confirmed the hypothesis that these larvae were incorporated as it developed in proximity to the shelf break. The significantly larger larval size of temperate neritic taxa (e.g. Sardinops sagax, Engraulis australis) in the eddy compared with the shelf suggests that these larvae were transported from the shelf adjacent to the developing eddy. The occurrence of tropical neritic taxa (e.g. Acanthuridae, Lutjanidae, Pomacentridae) highlighted the LC as an important transport route to higher latitudes. Coupling the sampling of larval fishes with the trajectories of Lagrangian drifters provided insight into how larval fish assemblages changed during development of the eddy.

Keywords: Apterichtus; Ophichthidae; pseudoparasitism; prey; common pandora; western Mediterranean.

Three snake eels (Ophichthidae) were found in three common pandoras (Pagellus erythrinus) from the north-western Mediterranean: two in the stomach and one embedded in the body cavity. This incidence corroborates previous records of snake eels found within fish. The role of the eels as possible prey, parasites or pseudoparasites is briefly discussed.

Keywords: benthos, community composition, ecosystem management, fishing, marine reserves, Mediterranean Sea.

This study focuses on 4 sites in the northwestern Mediterranean to investigate the response of benthic fauna across a gradient of trawling impact. One site was located in a heavily exploited fishing ground. The second site was enclosed in the fishing ground but had not been trawled in twenty years. The third site was located adjacent to a marine protected area and was subjected to occasional trawling. The fourth site was located inside the marine protected area, where trawling was banned thirty years ago. Side-scan sonar records of trawl marks on the seabed confirmed the gradient of trawling intensity. We investigated the response of benthic fauna to trawling disturbance at the mesoscale of a fishing ground. We compared the observed patterns of abundance, biomass, diversity and community structure for epifauna and infauna with responses predicted from previous studies. Results showed that those communities less impacted by trawling sustained more biogenically habitat-structured communities (e.g. more abundance of sessile suspension feeders at the less disturbed sites against higher dominance of small invertebrates at the disturbed site). Moreover, these results confirm the benefits of restricting trawling activities for benthic communities, with marine reserves as the paradigm for the conservation of Mediterranean fishing grounds.

Keywords: Peracarida, benthos, spatial variations, muddy sediments, temperature, mucilaginous aggregates..

Short-term temporal variability in infaunal crustacean communities was evaluated against environmental variability. The area of study was located at two stations at 45 and 60 m depth under the influence of the Ebro River. Differences in the relative abundance of crustacean species between sites might be related to the distance from the river, with higher organic matter supply and finer mud content near the river. There was a marked seasonal variability linked to high phytoplankton production in spring, which supplied organic matter to the benthos, inducing higher crustacean abundance. In late summer there was a reduction in the infaunal crustacean abundance and species richness that could have been caused by two factors: the establishment of the thermocline, which could limit the availability of organic matter to the seabed, and the high water temperatures, which caused the production of phytoplankton exudates and accumulation of mucilaginous aggregates over the seabed. The 45-m site was under the influence of otter-trawl fishing and precisely in this area the seasonal variability was not observed, probably masked by the effects of trawling impact.

Keywords: Diversity measures · Habitats · Macroinfauna · New Zealand · Soft bottoms .

Species richness depends on both regional and local factors, including regional species pools and habitat type. We compared diversity, scaling from α (site species richness) to β (heterogeneity in species richness) and γ (location species richness), at 6 different intertidal habitat types within 8 coastal locations in the New Zealand North Island. Physical variables at each location (the harbour total area to high water, tidal prism and % intertidal) and habitat variables (comprising habitat fragmentation indices and number and size of patches) were correlated with the diversity measures, evaluating the importance of local variables against regional species pools. Results showed that differences in diversity indices within locations were greater than between locations, and that generally habitats with structuring fauna (cockles, seagrass, tubeworms) held higher diversity than purely sedimentary habitats (mud and sand). In all habitats except mud, local variables had significant interaction with diversity; patch size had a positive effect for all diversity measures, and fragmentation indices had negative effects. The intertidal extent also negatively affected diversity, especially regional species richness. These findings underline the importance of minimising habitat loss and fragmentation for the conservation of marine soft sediments.

Cephalopods play a key role in many marine trophic food webs and also constitute alternative fishery resources in the context of the ongoing decline in finfish stocks. Most coastal cephalopod species of commercial importance migrate into shallow waters during the breeding season to lay their eggs, and are consequently subjected to coastal contamination. Eggs of common cuttlefish Sepia officinalis, European squid Loligo vulgaris, common octopus Octopus vulgaris and the sepiolid Rossia macrosoma were exposed during embryonic development to dissolved 110mAg, 109Cd, 60Co, 54Mn and 65Zn in order to determine their metal accumulation efficiencies and distribution among different egg compartments. Cuttlefish eggs, in which hard shells enclose the embryos, showed the lowest concentration factor (CF) values despite a longer duration of exposure. In contrast, octopus eggs, which are only protected by the chorionic membrane, accumulated the most metal. Uptake appears to be linked to the selective retention properties of the egg envelopes with respect to each element. The study also demonstrated that the octopus embryo accumulated 110mAg directly from the dissolved phase and also indirectly through assimilation of the contaminated yolk. These results raise questions regarding the potential contrasting vulnerability of early life stages of cephalopods to the metallic contamination of coastal waters.

Keywords: GAM; temporal variations; fish larvae; environmental conditions; marine parks; geographical distributions; NW Mediterranean.

We assessed the linkages between environmental variables and the spatio-temporal distribution patterns of larval abundance of coastal fish assemblages within and outside the Medes Islands marine protected area (MPA; NW Mediterranean) to explore possible fisheries effects such as larvae export of the latter. We analyzed small-scale fish larvae distribution of 28 representative taxa from the rocky fish assemblage and combined the former in different groups with the help of cluster analysis. Further we assessed the influence of selected abiotic variables on group and species distributions using Generalized Additive Models (GAM’s). We found a high level of variability in the response of larvae groups and species to environmental variables over the two studied periods (spring and summer); depth and habitat of the adults being the most important factors. In addition, distance to the MPA was found as an important variable in defining the location of larvae of strictly coastal species. Our results provided evidence of larval export of three commercial species affected by the MPA (Epinephelus marginatus, Pagellus erythrinus and Scorpaena porcus). Thus our study contributes to the few empirical assessments of larvae export from MPAs and adds to the understanding of the functioning of MPAs as fisheries management tools. Nevertheless, in the future integrated assessments of fisheries effects of MPAs are required that measure the effect of larvae and biomass export on increased fishing yield while taking into account fishing effort dynamics.

Keywords: ecological history - marine populations - exploitation - habitat loss - eutrophication - extinction - invasion - food-web structure - ecosystem modelling.

The Mediterranean Sea has been strongly influenced by human activities for millennia. Although the environmental history of its surrounding terrestrial ecosystems has received considerable study, historical changes in its marine realm are less known. We used a multidisciplinary approach combining paleontological, archeological, historical, fisheries, and ecological data to reconstruct past changes in marine populations, habitats, and water quality in the Adriatic Sea. Then, we constructed binary food webs for different historical periods to analyze possible changes in food-web structure and functioning over time. Our results indicate that human activities have influenced marine resource abundance since at least Roman times and accelerated in the nineteenth and twentieth centuries. Today, 98% of traditional marine resources are depleted to less than 50% of former abundance, with large (>1 m) predators and consumers being most affected. With 37% of investigated species rare and 11% extirpated, diversity has shifted towards smaller, lower trophic-level species, further aggravated by more than 40 species invasions. Species providing habitat and filter functions have been reduced by 75%, contributing to the degradation of water quality and increased eutrophication. Increased exploitation and functional extinctions have altered and simplified food-web structure over time, especially by changing the proportions of top predators, intermediate consumers, and basal species. Moreover, simulations of species losses indicate that today’s ecosystems may be less robust to species extinctions than in the past. Our results illustrate the long-term and far-reaching consequences human activities can have on marine food webs and ecosystems.

Many marine populations and ecosystems have experienced strong historical depletions, yet reports of recoveries are increasing. Here, we review the growing research on marine recoveries to reveal how common recovery is, its magnitude, timescale and major drivers. Overall, 10–50% of depleted populations and ecosystems show some recovery, but rarely to former levels of abundance. In addition, recovery can take many decades for long-lived species and complex ecosystems. Major drivers of recovery include the reduction of human impacts, especially exploitation, habitat loss and pollution, combined with favorable life-history and environmental conditions. Awareness, legal protection and enforcement of management plans are also crucial. Learning from historical recovery successes and failures is essential for implementing realistic conservation goals and promising management strategies.

Keywords: Balearic shearwater · Geographical foraging ground segregation · Habitat modelling · Mediterranean Sea · Oceanography · Puffinus mauretanicus · Stable isotopes.

While breeding, seabirds are limited to exploiting resources within a restricted area around their breeding site and should exploit the closest productive marine areas within their distribution range. We investigated this hypothesis in one of the most endangered European seabirds, the Balearic shearwater Puffinus mauretanicus (ca. 3200 breeding pairs), restricted to the Balearic Islands. Our aims were (1) to assess whether isotopic evidence (i.e. stable isotopes of δ13C and δ15N) of foraging habitat partitioning occurs among northern, central and southern populations, (2) to geographically locate population-specific potential foraging grounds along the Iberian continental shelf, and (3) to assess whether oceanographic conditions could explain observed patterns of stable isotopes (SI). SI values showed a latitudinal gradient, with birds from the northern population having lower δ15N and δ13C values than central and southern populations. Potential foraging grounds of northern, central and southern populations were centred in Cape Creus, Ebro Delta and Cape La Nao, respectively, results which were supported by habitat models. Oceanographic conditions in each potential foraging ground were different; the northern population used richer, colder and deeper waters compared to the central and southern populations. Chlorophyll a was the main oceanographic variable that explained variation in SI values. We hypothesised that SI differences among Balearic shearwater populations might be a consequence of differences in baseline isotopic values among potential foraging grounds rather than real differences in diet. Our comprehensive study also provides important information for management strategies to conserve this critically endangered shearwater.

Keywords: Macrofauna; Canyon; Food availability; Seasonal dynamics.

A seasonal analysis of deep-sea infauna (macrobenthos) based on quantitative sampling was conducted over the Catalan Sea slope, within the Besòs canyon (at ∼550–600 m) and on its adjacent slope (at 800 m). Both sites were sampled in February, April, June–July and October 2007. Environmental variables influencing faunal distribution were also recorded in the sediment and sediment/water interface. Dynamics of macrobenthos at the two stations showed differences in biomass/abundance patterns and trophic structures. Biomass was higher inside the Besòs canyon than on the adjacent slope. The community was mostly dominated by surface-deposit feeding polychaetes (Ampharetidae, Paraonidae, Flabelligeridae) and crustaceans (amphipods such as Carangoliopsis spinulosa and Harpinia spp.) inside the canyon, while subsurface deposit feeders (mainly the sipunculan Onchnesoma steenstrupii) were dominant over the adjacent slope. The taxonomic composition in the suprabenthic assemblages of polychaetes, collected on the adjacent slope by a suprabenthic sledge, was clearly different from that collected by the box-corer. The suprabenthic assemblage was dominated by carnivorous forms (mainly Harmothoe sp. and Nephthys spp.) and linked to higher near-bottom turbidity. Inside Besòs a clear temporal succession of species was related to both food availability and quality and the proliferation of opportunistic species was consistent with higher variability in food sources (TOC, C/N, δ13C) in comparison to adjacent slope. This was likely caused by a greater influence of terrigenous inputs from river discharges. Inside the canyon, Capitellidae, Spionidae and Flabelligeridae, in general considered as deposit feeders, were more abundant in June–July coinciding with a clear signal of terrigenous carbon (depleted δ13C, high C/N) in the sediments. By contrast, during October and under conditions of high water turbidity and increases of TOM, carnivorous polychaetes (Glyceridae, Onuphidae) increased. Total macrobenthos biomass found over Catalonian slopes were higher than that found in the neighboring Toulon canyon, probably because the two canyons are influenced by different river inputs, connected with distinct terrigenous sources.

Keywords: Beggiatoa; Cabled ocean observatories; Hypoxia; Oceanographic data acquisition; Rhythmic behaviour; Underwater camera.

Understanding biological rhythms in benthic ecosystems and their modulation by habitat cycles has important implications for resource and ecosystem management. The recent development of permanent, multi-sensor seafloor observatories in deep-water environments provides opportunities for the in situ investigation of the behaviour of benthic organisms in relation to habitat variability. This paper describes a multi-disciplinary investigation at the VENUS observatory platform in Saanich Inlet, an intermittently anoxic fjord (Vancouver Island, Canada). A remotely operated digital camera (103 m depth) was used to document changes in the abundance of shrimp (Spirontocaris spp.) and the squat lobster (Munida quadrispina), as well as bacterial mat coverage (Beggiatoa spp.). These data were used as proxies of diel rhythms related to day–night and internal tidal cycles. Seafloor photos were acquired hourly during consecutive days, before, during and after oxygen intrusion events in the fall of 2009. In order to relate biological fluctuations to habitat cycles, bottom water pressure, temperature, dissolved oxygen, and nitrate data were also acquired from the observatory database. Periodogram analysis showed a weak internal-tide-associated rhythmicity for Spirontocaris spp. that was absent in M. quadrispina and in bacterial mat coverage. Waveform analysis confirmed the absence of any day–night fluctuation in all tested species. However, a rapid intrusion of oxygenated water at the study site influenced visual counts of species, possibly blurring detectable activity rhythms. Temperature and nitrate fluctuations were more accentuated during spring tides but cross-correlation analysis indicated an absence of species responses to these habitat variables. Results are discussed within the context of the complex oceanographic dynamics of Saanich Inlet and with respect to understanding the ecological consequences of expanding hypoxia in the global ocean.

Keywords: Fishing tactics; Gillnet; Métiers; Multivariate analysis; Northwestern Mediterranean; Small-scale fishery; Trammel net.

We analyzed the small-scale fishery in the port of Vilanova i la Geltrú (NW Mediterranean) to assess the fishing practices in this fishery and produce economic indicators of its status. We defined the fishing tactics (or métiers) of this fishery with a multivariate analysis approach for evaluating the main fishery resources and fishing gears employed. Our results show that netters in this fishery practice 7 types of fishing tactics. Five of these fishing tactics, in terms of target species, gear and seasonality, are also used in other small-scale Mediterranean fisheries. The main types of fishing gear (trammel nets, gillnets) and target species (Sepia officinalis, Solea vulgaris, Mullus surmuletus and Merluccius merluccius), and a well defined seasonality, are also observed in other studies of Mediterranean small-scale fisheries. We show that the seasonal rotation of fishing tactics is determined by the availability of different fish species rather than market price. Identifying the fishing tactics, which in the Mediterranean are relatively limited in number, of small-scale fisheries provides information for developing monitoring and management strategies for these fisheries. We also assessed the economic performance of the small-scale fishery in Vilanova i la Geltrú and its conflicts with other uses of the coastal zone. We conclude that small-scale fisheries are an economically viable activity although seriously threatened by concurrent uses of the coastal zone (conflict with other extractive activities; competition for space with tourism and leisure activities; pollution). The integrated management of the uses of the coastal zone is necessary in order to sustain small-scale fisheries, which have become less important in economic terms, but which are an important social component of local coastal communities and are a source of high quality seafood with a low ecological impact. © EDP Sciences, IFREMER, IRD 2011.

Keywords: Isidella elongata; deep-sea corals; trawl fisheries; ecological impact; Aristeus antennatus; Mediterranean Sea.

Deep-water corals are known to provide essential habitat for fish and invertebrates along the continental slope in different areas of the world, offering prey to coral predators, protection or attachment substrate to other suspension feeders. In the Mediterranean Sea the coral Isidella elongata (Esper, 1788) characterizes a facies of bathyal compact mud substrates between 500 and 1200 m depth. Based on 4 experimental surveys carried out between 1985 and 2008, we obtained quantitative data on the fauna associated with live coral stands. We show that species richness of invertebrates and crustaceans, as well as abundance and biomass of crustaceans, is higher in areas with large stands of the coral. Some commercial fishery species are also more abundant or reach larger sizes in areas with high density of the coral, particularly the red shrimps Aristeus antennatus (Risso, 1816) and Plesionika martia (A. Milne Edwards, 1883). Trawling over I. elongata facies causes direct impacts on the biological assemblages by removing the habitat-forming corals, decreasing invertebrate species diversity and negatively affecting fisheries production in the long term.

We conducted interviews of a representative sample of 106 retired fishers in Italy, Spain and Greece, asking specific questions about the trends they perceived in dolphin and shark abundances between 1940 and 1999 (in three 20 year periods) compared to the present abundance. The large marine fauna studied were not target species of the commercial fleet segment interviewed (trawl fishery). The fishers were asked to rank the perceived abundance in each period into qualitative ordinal classes based on two indicators: frequency of sightings and frequency of catches (incidental or intentional) of each taxonomic group. The statistical analysis of the survey results showed that both incidental catches and the sighting frequency of dolphins have decreased significantly over the 60+ years of the study period (except for in Greece due to the recent population increase). This shows that fishers\' perceptions are in agreement with the declining population trends detected by scientists. Shark catches were also perceived to have diminished since the early 1940s for all species. Other long-lived Mediterranean marine fauna (monk seals, whales) were at very low levels in the second half of the 20th century and no quantitative data could be obtained. Our study supports the results obtained in the Mediterranean and other seas that show the rapid disappearance (over a few decades) of marine fauna. We show that appropriately designed questionnaires help provide a picture of animal abundance in the past through the valuable perceptions of fishers. This information can be used to complement scientific sources or in some cases be taken as the only information source for establishing population trends in the abundance of sensitive species.

Keywords: Kiss2; Kisspeptin-2; Puberty; Fasting; Alternative splicing; Solea senegalensis.

Kisspeptin signaling in the brain is involved in the control of the onset of puberty in vertebrates. In this study, we present novel evidence indicating that kisspeptin may link energy balance and reproduction. For that purpose, we determined the complete gene structure of kisspeptin in a teleost fish, the Senegalese sole (Ss). In contrast to the situation evident in several fish, in this species only Kiss2 was found. Yet, two Ss Kiss2 isoforms generated by alternative splicing through intronic retention were detected: Ss Kiss2_v1, producing the functional protein, and Ss Kiss2_v2, coding for a truncated, non-functional protein. Specific qPCRs showed that the expression of these two isoforms varied differently in brain and gonads throughout maturation. In addition, and in contrast to what has been observed in mammals, fasting increased hypothalamic mRNA levels of Ss Kiss2_v1, which also caused a concomitant rise in pituitary Ss LH and Ss FSH mRNA. Together, these data indicate the impact of the nutritional status on Kiss mRNA expression as a potential regulatory mechanism for the metabolic control of reproduction in non-mammalian species, albeit with some significant differences with respect to the situation described in mammals.

Keywords: Feeding strategy · Daily ration · Juvenile Merluccius merluccius · Northwestern Mediterranean.

Predation, feeding strategy (FS) and food daily ration (DR) were analysed in juveniles of the European hake Merluccius merluccius during a 24 h trawl survey carried out in the northwestern Mediterranean. Predatory activity, expressed as the stomach fullness index (FI) and prey digestion stage, was initiated in the early night and continued throughout the night, reaching maximum activity in the early morning. The feeding activity progressively decreased after this time, reaching a minimum before sunset, when a rest phase was observed. Changes in prey taxa during the 24 h cycle indicated that prey selection was time-of-day and predator-size dependent. Zooplankton crustaceans were mostly consumed during the night and in the early afternoon. The 2 main categories (euphausiids and mysids) comprising the zooplankton and hyperbenthos trophic resource of the hake, were consumed in a temporally shifted manner, such that the macrozooplankton (euphausiids) was consumed at night and the hyperbenthos (mysids) during the day. FS and length-distribution analysis indicated that early juveniles (9.3 ± 1.7 cm total length, TL) primarily fed on these resources in these periods. In contrast, advanced juveniles (12.0 ± 3.4 cm TL) preyed largely on decapod crustaceans and fishes and fed mostly during the day, exhibiting a more specialised FS. Differences in the DR were estimated using Exponential (Exp) and Square-root (Sq-r) models, the latter taking into account predator size. The Exp model yielded a mean consumption of 1.5% body wet weight (BWW) and the Sq-r model yielded mean values ranging between 4.09 and 5.09% BWW, with a difference between the 2 methods ranging from 63 to 70% larger for the latter method. Therefore, the application of the Sq-r model gives an alternative insight into the range of consumption in juvenile hakes.

Feeding ecology was analysed for the first time in the larvae of the European hake (Merluccius merluccius) to determine whether their diet and selectivity were constrained by environmental conditions and how these feeding characteristics were related to ontogeny, prey availability and visual capabilities. Larvae collected during both day and night were analysed, and it was found that feeding incidence was high, regardless of the time of day. Examination of the visual system corroborated the hypothesis that hake larvae should be able to cope with a wide range of photic conditions and to forage even at low light intensity. A clear preference for adult calanoid copepods and, especially, for Clausocalanus spp. was observed in all sizes analysed. Prey number increased with larval size, but prey size did not. This finding indicates that hake larvae behave as selective and specialist predators that consume an increasing number of prey rather than larger prey during larval growth.

The Mediterranean Sea (0.82% of the global oceanic surface) holds 4%–18% of all known marine species (not, vert, similar17,000), with a high proportion of endemism [[1] and [2]]. This exceptional biodiversity is under severe threats [1] but benefits from a system of 100 marine protected areas (MPAs). Surprisingly, the spatial congruence of fish biodiversity hot spots with this MPA system and the areas of high fishing pressure has not been assessed. Moreover, evolutionary and functional breadth of species assemblages [3] has been largely overlooked in marine systems. Here we adopted a multifaceted approach to biodiversity by considering the species richness of total, endemic, and threatened coastal fish assemblages as well as their functional and phylogenetic diversity. We show that these fish biodiversity components are spatially mismatched. The MPA system covers a small surface of the Mediterranean (0.4%) and is spatially congruent with the hot spots of all taxonomic components of fish diversity. However, it misses hot spots of functional and phylogenetic diversity. In addition, hot spots of endemic species richness and phylogenetic diversity are spatially congruent with hot spots of fishery impact. Our results highlight that future conservation strategies and assessment efficiency of current reserve systems will need to be revisited after deconstructing the different components of biodiversity.

Keywords: Ecopath model; Ecosystem model; Marine food-webs; Marine predators; Trophic position; Stable isotopes.

Understanding how marine ecosystems are structured and how they function is a scientific challenge. Nowadays, to learn about ecosystem trophic dynamics ecologists use two complementary methodological approximations, mass-balance ecosystem models and isotopic tools. However, despite the wide applications of these methodologies, the comparison and combination of both are still scarce. The aim of this study was to examine the trophic dynamics of representative species of the South Catalan marine ecosystem (North-western Mediterranean) using the Ecopath ecosystem modelling tool and the stable isotope approach. By using the two methodologies we depicted the trophic position (trophic level and δ15N values) and trophic width (omnivory index and total isotopic area) of several species of fish, cephalopods, cetaceans, seabirds and one sea turtle. Our results show a clear correlation between the trophic levels estimated by the Ecopath model and the δ15N values, which validate the trophic position of several species in the study area and indicate that both methodologies are useful to determine the trophic position of marine species in Mediterranean marine food webs. In contrast, the two estimators of trophic width (the omnivore index and the total isotopic area) were not strongly related, since the relationship between modelling and stable isotope results was evident only for some species. Further comparisons of trophic width calculated in other marine food webs may provide a better understanding of our results and validate the accuracy of both methodological approaches to calculate trophic width.

Sex ratio shifts in response to temperature are common in fish and reptiles. However, the mechanism linking temperature during early development and sex ratios has remained elusive. We show in the European sea bass (sb), a fish in which temperature effects on sex ratios are maximal before the gonads form, that juvenile males have double the DNA methylation levels of females in the promoter of gonadal aromatase (cyp19a), the enzyme that converts androgens into estrogens. Exposure to high temperature increased the cyp19a promoter methylation levels of females, indicating that induced-masculinization involves DNA methylation-mediated control of aromatase gene expression, with an observed inverse relationship between methylation levels and expression. Although different CpGs within the sb cyp19a promoter exhibited different sensitivity to temperature, we show that the increased methylation of the sb cyp19a promoter, which occurs in the gonads but not in the brain, is not a generalized effect of temperature. Importantly, these effects were also observed in sexually undifferentiated fish and were not altered by estrogen treatment. Thus, methylation of the sb cyp19a promoter is the cause of the lower expression of cyp19a in temperature-masculinized fish. In vitro, induced methylation of the sb cyp19a promoter suppressed the ability of SF-1 and Foxl2 to stimulate transcription. Finally, a CpG differentially methylated by temperature and adjacent to a Sox transcription factor binding site is conserved across species. Thus, DNA methylation of the aromatase promoter may be an essential component of the long-sought-after mechanism connecting environmental temperature and sex ratios in vertebrate species with temperature-dependent sex determination.

Keywords: Daily ration · Feeding periodicity · Sardine · Sardina pilchardus · Mediterranean Sea · Aegean Sea.

The diel variation in feeding intensity and daily ration of the sardine Sardina pilchardus (Walbaum, 1792) was investigated based on 50 pelagic trawl hauls carried out during the period of thermal stratification (July 2007 and July 2008) and mixing (December 2007 and February 2009) in a coastal area of the North Aegean Sea (eastern Mediterranean). Concurrently collected hydrographic (temperature and salinity), plankton (chlorophyll a, microzooplankton and mesozooplankton) and fish parameters (somatic condition, sexual maturity and catch per unit effort of sardine, CPUE) were used to explain seasonal and inter-annual variability in feeding periodicity and daily ration. A piecewise regression fitted to the weight-length data indicated a significant inflexion point at a length of ~100 mm that was used to split the fish sample into adults and juveniles. The stomach fullness index (stomach content mass/fish mass) was strongly dependent on size, and a generalized linear model was used instead to standardize stomach content mass. During summer, sardine fed consistently during daytime with a prominent peak at around sunset. In winter, high feeding rates were recorded in the early night (first 6 h after sunset) but not in the second half of the night. Field estimates of gastric evacuation rate (R) ranged from 0.101 to 0.225 h−1 and were strongly related to temperature (T) (R = 0.075e0.038T, r2 = 0.785). Daily rations were estimated by applying the Elliott-Persson and the Eggers models and varied from 2.02 to 3.67% total weight (TW) in adults and 4.18 to 5.36% TW in juveniles. A significant positive relationship emerged when daily ration was regressed against the ratio of mesozooplankton biomass to sardine CPUE, implying a density-dependent rate of food consumption.

Keywords: Parapenaeus longirostris, Aristeus antennatus, trophic relationships, southwestern Mediterranean, Algerian waters..

With the aim of analyzing the trophic dynamics of deep-sea shrimp over the central Algerian slope, stomach contents of 219 individuals of Parapenaeus longirostris and 263 Aristeus antennatus were collected at night at depths between 200 and 400 m on a seasonal scale in 2007. Fullness (f), which is a measure of feeding intensity, showed significant seasonal changes in Aristeus antennatus, and the highest f was found in pre-reproductive periods (3.3% in January; 3.0% in April) before the beginning of gonad maturation (April-September in the area). This trend was coupled with the period of high surface productivity off the central Algerian coast (November-April). In that pre-reproductive period A. antennatus consumed more crustaceans (e.g. large decapods such as Processa sp.) with a high energetic value. These kinds of seasonal oscillations in f were not found in P. longirostris, probably because it was distributed shallower than A. antennatus and does not have a single marked peak in its reproductive cycle. The dietary composition of P. longirostris and A. antennatus was clearly segregated in the MDS analysis, which suggests there is good resource partitioning between the two species. Foraminiferans, bivalves and polychaetes were the most frequent prey in the diet of both P. longirostris and A. antennatus. Small micro and mesoplankton prey (radiolarians, tintinnids, copepods and pteropods) were more important in the diet of P. longirostris, while A. antennatus fed more on benthos. Planktonic prey found in the diet of the two shrimp were more frequent in January-February and April-May, e.g. in periods of higher water homogeneity coupled with periods of higher surface production. The large contribution of zooplankton to the diet of the deep-water shrimp over Algerian slopes is probably due to the importance of eddies in the area, which may enhance water column production locally. The high surface temperature (lowest T in January of 15.2°C) may accelerate the degradation of the organic matter that reaches Algerian slope bottoms, thus reducing the biomass of macrobenthos. We hypothesized that this low availability of benthic food resources may favour night time migratory movements by benthopelagic shrimp off the Algerian coast in search of more productive, shallow bottoms.

Keywords: Bayesian; coalescence; DAPC; diversity; long-lived species; microsatellites; phyllosoma; phylogeography.

Defining population structure and genetic diversity levels is of the utmost importance for developing efficient conservation strategies. Overfishing has caused mean annual catches of the European spiny lobster (Palinurus elephas) to decrease alarmingly along its distribution area. In this context, there is a need for comprehensive studies aiming to evaluate the genetic health of the exploited populations. The present study is based on a set of ten nuclear markers amplified in 331 individuals from ten different localities covering most of P. elephas distribution area. Samples from Atlantic and Mediterranean basins showed small but significant differences, indicating that P. elephas populations do not behave as a single panmictic unit but form two partially-overlapping groups. Despite intense overfishing, our dataset did not recover a recent bottleneck signal, and instead showed a large and stable historical effective size. This result could be accounted for by specific life-history traits (reproduction and longevity) and the limitations of molecular markers in covering recent timescales for nontemporal samples. The findings of the present study emphasize the need to integrate information on effective population sizes and life-history parameters when evaluating population connectivity levels from genetic data

Keywords: DNA barcoding, Achelata, Scyllaridae, slipper lobster, Scyllarus, S. arctus, S. pygmaeus.

Advanced stages of Scyllarus phyllosoma larvae were collected by demersal trawling during fishery research surveys in the western Mediterranean Sea in 2003–2005. Nucleotide sequence analysis of the mitochondrial 16S rDNA gene allowed the final-stage phyllosoma of Scyllarus arctus to be identified among these larvae. Its morphology is described and illustrated. This constitutes the second complete description of a Scyllaridae phyllosoma with its specific identity being validated by molecular techniques (the first was S. pygmaeus). These results also solved a long lasting taxonomic anomaly of several species assigned to the ancient genus Phyllosoma Leach, 1814. Detailed examination indicated that the final-stage phyllosoma of S. arctus shows closer affinities with the American scyllarid Scyllarus depressus or with the Australian Scyllarus sp. b (sensu Phillips et al., 1981) than to its sympatric species S. pygmaeus.

Keywords: sublittoral, megabenthos, faunal assemblages, sediment characteristics, biodiversity, NW Mediterranean, coarse sand, Bivalvia, Crustacea..

The sublittoral megabenthic assemblages of a northwestern Mediterranean coarse sandy beach exploited for the bivalve Callista chione were studied. The spatial and bathymetric variability of its distinctive faunal assemblages was characterised by quantitative sampling performed with a clam dredge. The taxa studied were Mollusca Bivalvia and Gastropoda, Crustacea Decapoda, Echinodermata and Pisces, which accounted for over 99% of the total biomass. Three well-differentiated species assemblages were identified: (1) assemblage MSS (Medium Sand Shallow) in medium sand (D50=0.37 mm) and shallow waters (mean depth =6.5 m), (2) assemblage CSS (Coarse Sand Shallow) in coarse sand (D50=0.62 mm) in shallow waters (mean depth =6.7 m), and (3) assemblage CSD (Coarse Sand Deep) in coarse sand (D50=0.64 mm) in deeper waters (mean depth =16.2 m). Assemblage MSS was characterised by the codominance of the bivalves Mactra stultorum and Acanthocardia tuberculata. C. chione was dominant in both density and biomass in assemblages CSS and CSD. The occurrence of the crab Thia scutellata also characterised assemblage CSS, whereas the occurrence of the sea urchin Echinocardium mediterraneum characterised assemblage CSD. A depth breaking point of around 10 m determined the discontinuity between assemblages CSS and CSD, which was related to the closure depth of the beaches in the study area. Species richness was highest in the coarse sand communities; however, Shannon-Wiener diversity and Pielou equitability indexes were higher in the shallow fine sand community.

The deep sea, the largest ecosystem on Earth and one of the least studied, harbours high biodiversity and provides a wealth of resources. Although humans have used the oceans for millennia, technological developments now allow exploitation of fisheries resources, hydrocarbons and minerals below 2000 m depth. The remoteness of the deep seafloor has promoted the disposal of residues and litter. Ocean acidification and climate change now bring a new dimension of global effects. Thus the challenges facing the deep sea are large and accelerating, providing a new imperative for the science community, industry and national and international organizations to work together to develop successful exploitation management and conservation of the deep-sea ecosystem. This paper provides scientific expert judgement and a semi-quantitative analysis of past, present and future impacts of human-related activities on global deep-sea habitats within three categories: disposal, exploitation and climate change. The analysis is the result of a Census of Marine Life – SYNDEEP workshop (September 2008). A detailed review of known impacts and their effects is provided. The analysis shows how, in recent decades, the most significant anthropogenic activities that affect the deep sea have evolved from mainly disposal (past) to exploitation (present). We predict that from now and into the future, increases in atmospheric CO2 and facets and consequences of climate change will have the most impact on deep-sea habitats and their fauna. Synergies between different anthropogenic pressures and associated effects are discussed, indicating that most synergies are related to increased atmospheric CO2 and climate change effects. We identify deep-sea ecosystems we believe are at higher risk from human impacts in the near future: benthic communities on sedimentary upper slopes, cold-water corals, canyon benthic communities and seamount pelagic and benthic communities. We finalise this review with a short discussion on protection and management methods.

Keywords: calamar gigante, Dosidicus giga, Vinciguerria lucetia, relacionas tróficas, método acústico, corriente de Humboldt.

La biomasa de calamar gigante Dosidicus giga y el pez mesopelágico Vinciguerria lucetia se obtuvo a partir de detección acústica en la Corriente de Humboldt de Perú durante 2007 y 2008. Simultáneamente, 937 clamares fueron cpaturados y se les analizó el contenido estomacal. La dieta de D. gigas estuvo dominada por peces, siendo V. lucetia el principal componente y en segundo lugar el mictófido Diogenichthys laturnatus. A partir de la evaluación de la biomasa de ambas especies, estimada por el método acústico, se observó que V. lucetia es uno de los principales componentes en el sistema de la Corriente de Humboldt de Perú y sus patrones de distribuciçon y movimientos espacio-temporal están fuertemente relacionados a los desplazamientos migratorios del calamar. Estas relaciones tróficas promueven un incremento de la biomasa de D. gigas que es resultado de un patrón similar en V. lucetia, lo que propicia un efecto trófico positivo en el ecosistema oceánico.

Keywords: Canopy structure · Nitrogen retention · Carbon storage · Juvenile habitat · Diversity · Food-web structure · Species extinction · Human impacts.

Marine vegetated habitats provide essential functions and services to ocean ecosystems and human well-being. It is unclear however, how different habitat types compare. Using large-scale field surveys, we compared the canopy and community structure between eelgrass and rockweed beds in Atlantic Canada and assessed their nitrogen retention, carbon storage, and habitat services. We then used binary network models of predator-prey interactions to determine food-web structure and their robustness to species loss. Despite disparate 3-dimensional canopy structure, both habitats significantly enhanced overall abundance and diversity of associated flora and fauna, including several commercially important species. Significant differences occurred in the species assemblages within and between habitats and were attributed to different settlement opportunities, food availability, predation risk, and maneuverability. While eelgrass plants had higher nitrogen content, rockweed canopies maintained 8-fold greater biomass and thus 14-fold greater nitrogen and 8-fold greater carbon retention per unit area. Both rockweed and eelgrass food webs showed similarities to other temperate and tropical seagrass webs, yet their robustness to the loss of most connected species including primary producers was among the lowest; underscoring their vulnerability to disturbances affecting the functionally dominant primary producers. Our study demonstrates that marine vegetation provides important habitat, nitrogen and carbon storage services, yet the extent of these services depends on the foundation species and its architecture. Changes in canopy structure will therefore have profound effects on associated food webs and ecosystem services. Thus, as increasing human pressures on coastal ecosystems threaten the continued supply of essential functions and services, the protection of marine vegetated habitats should be a management priority.

Keywords: diversity, megafauna, deep sea, western Mediterranean, western Ionian, eastern Ionian.

Abundance, biomass and diversity patterns of bathyal and abyssal Mediterranean megafauna (fishes and invertebrates) were analyzed in the western Balearic Sea, the western Ionian Sea and the eastern Ionian Sea. Sampling was conducted with a Otter-trawl Maireta System (OTMS) at depths ranging from 600 to 4000 m. A series of ecological indicators were computed: total abundance and biomass, Margalef species richness, Shannon-Wiener diversity and Pielou’s index of evenness. A multidimensional scaling was applied, indicating that the megafauna communities were grouped by depth, while geographic area had a less defined influence. Margalef richness declined with depth in all three areas, but more steeply in the western Ionian Sea. Pielou’s evenness behaved differently in the three zones, showing a V-shaped curve in the eastern Ionian while showing a decreasing pattern in the other two areas. At lower slope depths, massive presence of the fishes Alepocephalus rostratus in the western basin and Bathypterois mediterraneus in the central basin caused a sharp reduction in evenness.

Keywords: Deep-sea · Mediterranean · Megafauna · Environmental factors · POC · Biodiversity.

The Mediterranean deep sea, being isothermal and longitudinally trophic-graded, is an optimal natural benchmark to test for macro-ecological patterns of species distribution. The relevance of environment−biota interactions on deep-sea megafauna in the Mediterranean Sea, a matter still neglected, is addressed here along longitudinal and bathymetric axes. Benthic and nektobenthic megafauna were collected in the 3 basins of the Mediterranean: the western (Catalan Sea and southern Balearic), central (western Ionian) and eastern (south of Crete) basins, with an otter-trawl Maireta system and an Agassiz dredge between 1200 and 4000 m depth. Simultaneously, environmental data were collected on surface production, near-bottom physical parameters, sediment grain size and carbon content. Megafaunal biomass was higher in the Catalan Sea, decreasing eastward and with depth. Species diversity and evenness were relatively constant in the western and central Mediterranean at all depths, whereas these indices decreased with depth in the eastern Mediterranean. β-diversity analyses indicated a high species turnover between areas. The 3 basins presented significantly different environmental conditions. Sediment particulate organic carbon, surface fluorescence and sediment grain size were the 3 environmental variables that best explained the distribution of megabenthos along the longitudinal Mediterranean axis. These results show that the food supply, from either the surface or from the adjacent deep-sea floor, is critical in regulating the biodiversity of deep-sea Mediterranean megafauna and that this diversity is pooled region-wide. The heterogeneity of resources may be essential in maintaining these high levels of local and regional diversity.

Keywords: Area cover · Benthic communities · Digital photography · Image analysis · Hierarchical segmentation.

An important aspect of marine research is to quantify the areal coverage of benthic communities. It is technically feasible to efficiently obtain images of marine environments at different depths and benthic habitats over large spatial and temporal scales. Currently, there is a large and growing library of digital images to analyze, representing a valuable benthic ecological archive. Benthic coverage is the basis of studies on biodiversity, characterization of communities and evaluation of changes over temporal and spatial scales. However, there is still a lack of automatic or semi-automatic analytical methods for deriving ecologically relevant data from these images. We introduce a software program named Seascape to obtain semi-automatically segmented images (patch outlines) from underwater photographs of benthic communities, where each individual patch (species/categories) is routinely associated to its area cover and perimeter. Seascape is an analog to the classical and better known discipline of landscape ecology approach, which focuses on the concept that communities can be observed as a patch mosaic at any scale. The process starts with a hierarchical segmentation, using a color space criteria adapted to the problem of segmenting complex benthic images. As an endproduct, we obtain a set of images ­segmented into classified homogenous regions at different resolution levels (hierarchical seg­mentation). To illustrate the versatility and capacity of Seascape, we analyzed 4 digital images from different habitats and depths: coral reefs (Pacific Ocean), coralligenous communities (NW Mediterranean Sea), deep-water coral reefs (NW Mediterranean Sea) and the Antarctic continental shelf (Weddell Sea). The development of this semi-automatic outline tool and its use for classification constitute an important step ­forward in the analysis and processing time of underwater seabed images at any scale.

Keywords: Embryo; Yolk metabolism; Gastrulation; Cathepsin; Enzyme processing.

The role of lysosomal proteases such as cathepsin B (Ctsb) and one of the paralogs of cathepsin L (Ctsla) during yolk metabolism in fish oocytes is well established. However, the function of Ctsb during embryogenesis, particularly in marine teleosts, has been poorly documented. In this study, the spatio-temporal expression of Ctsb and Ctsla, their enzymatic activities, and the processing of the Ctsb and its cellular localization, was investigated in developing embryos of the killifish (Fundulus heteroclitus). Both fhctsb and fhctsla transcript levels, as well as cathepsin B- and L-like activities, gradually increased in embryos from the 2–4 cell stage up to 7 days post-fertilization. During the morula to gastrula transition an increase of the active FhCtsb single chain form was followed by a rise in cathepsin B activity, which were apparently regulated by post-transcriptional mechanisms. During neurulation, a 8-fold increase in cathepsin B activity was accompanied by a more moderate increase in cathepsin L activity, which was 6-fold enhanced by 7 dpf. These increased catalytic activities were well-correlated to changes in the electrophoretic pattern of yolk proteins and a strong expression of fhctsb and its protein product in the yolk syncytial layer. The increase of cathepsin B activity was further correlated with an increment of the relative amount of the FhCtsb single and double chain forms, both active forms of FhCtsb. These results suggest that FhCtsb may be involved in the mechanisms underlying the onset of gastrulation in F. heteroclitus embryos, and may play complementary roles with FhCtsla during yolk metabolism.

Keywords: adaptive management; Barcelona; coastal management; Spain; Systems Approach Framework; urban beach.

The Systems Approach Framework is a methodological framework designed to enhance the efficacy of human decision-making processes within social-ecological systems with regard to sustainability. The objective of resilience adaptive management is to either maintain the system within the current regime such that the desired ecosystem goods and services continue to be delivered, or to move the system phase to a preferred regime. Although the objectives of the two frameworks are not exactly the same, there are considerable complementarities between them. Through application of the Systems Approach Framework in a case study regarding the urban beaches of Barcelona, Spain, we present some of the main findings revealed during the model construction and stakeholder participatory process. Additionally, we demonstrate that the Systems Approach Framework could be considered a useful step-by-step methodological guide that employs many of the vital components and processes of adaptive management.

Keywords: Egg development; Fecundity; Chaceon affinis; NE Atlantic.

The goal of this work was to elaborate on reproductive knowledge of the deep-sea red crab, Chaceon affinis, off the Canary Islands by providing information regarding its egg development and fecundity. Six stages for eggs were observed, from fully filled with yolk to the embryo occupying almost all the space inside the egg. A correlation was established between egg stage and the colour of the egg mass. Morphological analyses indicated that the eggs are spherical in shape and that they increase the 10.7% in maximum diameter from the initial to the final stage. Fecundity (AFE, annual fecundity estimation), defined as the number of eggs borne per females, was calculated with two methods, manual by hand counter and using an automated morphology system. No statistical differences for the relationships carapace width (CW)–AFE and total weight (TW)–AFE were detected between the two methods. The number of eggs ranged from 199,690 to 566,956 (105–160 mm CW). A positive correlation was obtained between AFE and CW (r2 = 0.672) and TW (r2 = 0.785).

Keywords: Microorganisms, science museums, Winogradsky columns, microbial ecosystems, oxygenic photosynthesis, cyanobacteria.

Microorganisms were first described by van Leeuwenhoek in the 17th century. Later, Pasteur and Koch related them to diseases. Since then, the scientific community has striven to extend awareness of the many junctions of microorganisms. Science museums provide an excellent setting in which to disseminate such knowledge, but the presentation of living microorganisms is a challenge. We describe an approach to the exhibition of living microorganisms pursued in a science museum in Barcelona (CosmoCaixa Barcelona). In two exhibits, the museum shows photosynthesis in cyanobacteria and Winogradsky columns, which provide an example of living microbial ecosystems.

Keywords: Catch per unit effort; fishery yields; marine protected area design; marine reserve; meta-analysis; spillover.

Marine protected areas (MPAs) are often promoted as tools for biodiversity conservation as well as for fisheries management. Despite increasing evidence of their usefulness, questions remain regarding the optimal design of MPAs, in particular concerning their function as fisheries management tools, for which empirical studies are still lacking. Using 28 data sets from seven MPAs in Southern Europe, we developed a meta-analytical approach to investigate the effects of protection on adjacent fisheries and asking how these effects are influenced by MPA size and age. Southern European MPAs showed clear effects on the surrounding fisheries, on the ‘catch per unit effort’ (CPUE) of target species, but especially on the CPUE of the marketable catch. These effects depended on the time of protection and on the size of the no-take area. CPUE of both target species and the marketable catch increased gradually by 2–4% per year over a long time period (at least 30 years). The influence of the size of the no-take area appeared to be more complex. The catch rates of the entire fishery in and around the MPA were higher when the no-take areas were smaller. Conversely, catch rates of selected fisheries that were expected to benefit most from protection increased when the no-take area was larger. Our results emphasize the importance of MPA size on its export functions and suggest that an adequate, often extended, time frame be used for the management and the evaluation of effectiveness of MPAs.

Keywords: Mysida, Mysidae, endemism, Mediterranean Sea, deep sea..

A new Erythropinae mysid, Dactylamblyops corberai n. sp., is described from specimens sampled with a 500-mm plankton net attached to a bottom trawl in the Ionian Sea (eastern Mediterranean). This new species is the first Dactylamblyops species described from the Mediterranean Sea. Based on a revision of additional material from several cruises made in recent years, we conclude that D. corberai is a widespread species in the deep Mediterranean near-bottom suprabenthic community at depths between 398 and 1859 m. The main distinguishing features of D. corberai are the shape of the eyes and their ocular process, and the shape of the labrum with two rows of clusters of short setules and two areas covered with small, scale-like protrusions not described in any other species of the genus. D. corberai belongs to the morphological hodgsoni group of Dactylamblyops species.

Keywords: birthdate distribution; environmental conditions; larval distribution; mackerel; recruitment; Scomber scombrus.

We investigate the effect of strong meteorological perturbations in early spring on the success of mackerel (Scomber scombrus) recruitment in the N/NW Iberian area (southern Bay of Biscay) for the period 1999–2008. In 2000, the year of the most pronounced recruitment failure on record, two consecutive multidisciplinary surveys sampled hydrographic conditions and mackerel eggs, larvae and post-larvae over the main mackerel spawning grounds of the north and northwest coast of the Iberian Peninsula. Analysis of egg and larval abundance and birthdates based on the otoliths of mackerel juveniles caught between July and October 2000 showed that there were no survivors from the early spring spawns, indicating a massive loss of early spawning effort. Moreover, the abundance of 1-year-old mackerel estimated from an acoustic survey carried out in 2001 was the lowest observed within the 1999–2008 time series. This low or null survival from the early spawns in 2000 could be due to the meteorological and oceanographic conditions of that spring, in particular two storm events in April after a relatively calm March. The first storm event from the north caused strong local wind in the southern Bay of Biscay but a weak oceanographic response. The second storm event from the southwest was mainly felt west of Galicia and caused a notable increase in shelf currents and a shift of the hydrographical structure along the shelf. Detailed analysis of strong wind pulses in early spring within the historical recruitment record suggests that strong local turbulence generated by high wind speeds and advection of larvae caused by the enhancement of shelf currents can contribute to reduced recruitment. Our observations indicate that, in 2000, both mechanisms were present.

Keywords: Cephalopoda; Gametes; Paralarvae; Teuthida.

Egg masses of oceanic squid accidently collected in the wild have been observed only from a few spawning events in aquaria, and as a consequence, the study of their embryos and hatchlings is very limited. Here, we used in vitro fertilization techniques to understand the abiotic factors that influenced egg development and hatchling performance of the ommastrephid squid Illex coindetii from the Mediterranean Sea. Egg and hatchling sizes of these ommastrephids are close to the minimum for cephalopod species, and therefore, short embryonic developmental periods were expected under a Mediterranean temperature regime. Low incubation densities and the use of antibiotics in the incubation medium resulted in relatively high survival rates to hatchling. Hatching time was inversely proportional to incubation temperature and ranged from 5 to 11 days at 21 °C and 13 °C, respectively. The addition of oviducal jelly to the eggs immediately after fertilization, followed by another addition at the beginning of organogenesis, resulted in better chorionic expansion, with an increase in egg diameter, delayed hatching and higher hatchling weight, which suggests a better use of yolk reserves. Larger hatchlings in length and weight also tended to be produced at low temperature, probably also due to better yolk absorption. As this species spawns all year round, size differences between summer and winter hatchlings may be suspected. In vitro fertilization techniques used in the laboratory proved to be useful in shedding some light on the early life of this oceanic squid. Further research is needed to elaborate on tests to predict gamete quality and to develop methods to avoid premature hatching.

Keywords: retinomotor, endogenous, circadian, cone contraction, latitude, equator, pole..

Like many physiological systems synchronised to the light:dark cycle, retinomotor movements in ‘lower’ vertebrates are controlled by both the ambient illumination and input from endogenous circadian oscillators. In the present study, we examine the relative influence of these two signals in various species of teleost fish with different latitudes of origin. We find equatorial species show very strong endogenous control. The cones of the glowlight tetra, for example, continue to go through undiminished cycles of contraction and relaxation that mirror the previous light:dark cycle for at least two weeks in continual darkness. To quantify the relative effectiveness of the ambient light compared with endogenous signals in causing cone contraction, the degree to which seven teleost species responded to light during the dark phase of their light:dark cycle was examined. In this situation the retina receives conflicting instructions; while the light is acting directly to cause light adaptation, any endogenous signal tends to keep the retinal elements dark adapted. The further from the equator a species originated, the more its cones contracted in response to such illumination, suggesting animals from higher latitudes make little use of endogenous oscillators and rely more on ambient illumination to control behaviours. Equatorial species, however, rely on internal pacemakers to a much greater degree and are relatively insensitive to exogenous light signals. Because these data are consistent with published observations in systems as diverse as melatonin synthesis in Arctic reindeer and the behaviour of regional populations of Drosophila, latitudinal clines in the efficacy of circadian oscillators may be a common feature among animals.

Keywords: aquaporin oocyte meiosis hydration yolk neofunctionalization.

The preovulatory hydration of teleost oocytes is a unique process among vertebrates. The hydration mechanism is most pronounced in marine acanthomorph teleosts that spawn pelagic (floating) eggs; however, the molecular pathway for water influx remains poorly understood. Recently, we revealed that whole-genome duplication (WGD) resulted in teleosts harboring the largest repertoire of molecular water channels in the vertebrate lineage and that a duplicated aquaporin-1 paralog is implicated in the oocyte hydration process. However, the origin and function of the aquaporin-1 paralogs remain equivocal. By integrating the molecular phylogeny with synteny and structural analyses, we show here that the teleost aqp1aa and -1ab paralogs (previously annotated as aqp1a and -1b, respectively) arose by tandem duplication rather than WGD and that the Aqp1ab C-terminus is the most rapidly evolving subdomain within the vertebrate aquaporin superfamily. The functional role of Aqp1ab was investigated in Atlantic halibut, a marine acanthomorph teleost that spawns one of the largest pelagic eggs known. We demonstrate that Aqp1ab is required for full hydration of oocytes undergoing meiotic maturation. We further show that the rapid structural divergence of the C-terminal regulatory domain causes ex vivo loss of function of halibut Aqp1ab when expressed in amphibian oocytes but not in zebrafish or native oocytes. However, by using chimeric constructs of halibut Aqp1aa and -1ab and antisera specifically raised against the C-terminus of Aqp1ab, we found that this cytoplasmic domain regulates in vivo trafficking to the microvillar portion of the oocyte plasma membrane when intraoocytic osmotic pressure is at a maximum. Interestingly, by coinjecting polyA+ mRNA from postvitellogenic halibut follicles, ex vivo intracellular trafficking of Aqp1ab is rescued in amphibian oocytes. These data reveal that the physiological role of Aqp1ab during meiosis resumption is conserved in teleosts, but the remarkable degeneracy of the cytoplasmic domain has resulted in alternative regulation of the trafficking mechanism.

Will there be fish in the ocean in 2050? To address this question, we made a data‐rich global assessment of how fish biomass has changed over the last hundred years. We built on more than 200 ecosystem models representing marine ecosystems throughout the world covering the period from 1880 to 2007, and all constructed based on the same approach. We used spatial modeling to distribute biomasses based on habitat preferences, ecology, and feeding conditions. We extracted over 68,000 estimates of fish biomass (for predatory and prey fishes, separately) distributed over time and space, and used multiple regression to predict biomass distributions. The regressions were highly significant and predict that the biomass of predatory fish in the world oceans has declined by two‐thirds over the last hundred years. This decline is accelerating, with 54% having taken place in the last 40 years. We also found that the biomass of prey fish has more than doubled over the last hundred years, likely as a consequence of predation release. Jointly, these findings allow us to predict that there will be fish in the ocean in 2050, but they will be mainly of small prey fish. Our study also addresses the controversy whether ‘fishing down the food web’ is a phenomenon actually occurring in nature or a sampling artifact due to catches not representing relative abundances in ecosystems. Our study strongly indicates that the impact of fisheries has caused fishing down the food web of ecosystem resources at the global level.

Keywords: 3D shape parameterization; EFD; 3D signature; 2D signature..

In this work we present a new method for compacting data from 3D shapes by extracting a 3D characteristic curve that we call a 3D signature. The 3D signature obtained preserves almost all the morphological shape information but drastically reduces the number of points required for representing the shape. Furthermore, based on the 3D signature, we present a 2D signature that draws a closed contour in a plane and that can be further compacted using elliptic Fourier descriptors. The method was developed to work with a 3D otolith database that is currently under construction.