Articles

153 documents.
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Solé M., M. Lenoir, J.-M. Fortuño, M. van der Schaar, M. André
Biology Open, 7, bio033860. DOI: 10.1242/bio.033860 (BibTeX: .etal.2018a)
Resum: Veure
The cephalopod statocyst and lateral line systems are sensory organs involved in orientation and balance. Lateral lines allow cephalopods to detect particle motion and are used for locating prey or predators in low light conditions. Here, we show the first analysis of damaged sensory epithelia in three species of cephalopod hatchlings (Sepia officinalis, Loligo vulgaris and Illex coindetii) after sound exposure. Our results indicate lesions in the statocyst sensory epithelia, similar to what was found in adult specimens. The novelty is that the severity of the lesions advanced more rapidly in hatchlings than in adult animals; i.e. the degree of lesions seen in hatchlings immediately after noise exposure would develop within 48 h in adults. This feature suggests a critical period of increased sensitivity to acoustic trauma in those species as has been described in developing mammalian cochlea and avian basilar papilla. The hair cells in the lateral lines of S. officinalis followed the same pattern of damage occurrence, while those of L. vulgaris and I. coindetii displayed a decreasing severity of damage after 24 h. These differences could be due to dissimilarities in size and life stages between the three species.
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Kiørboe T., E. Saiz, P. Tiselius, K.H. Andersen
Limnology and Oceanography, 63, 308-321. DOI: 10.1002/lno.10632 (BibTeX: kiorboe.etal.2018d)
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Corcione V., G. Grieco, M. Portabella, F. Nunziata, M. Migliaccio
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Valencia, Spain, 22-27 July, 2018., . (BibTeX: corcione.etal.2018)
Resum: Veure
In this study, the azimuth cut-off approach, which is typically adopted to estimate wind speed from Synthetic Aperture Radar (SAR) imagery collected under nominal wind conditions, is discussed with respect to high wind regime cases. First, the key roles played by the pixel spacing, the size of the boxes used to partition the SAR imagery and the image texture (homogeneity) are discussed in terms of their effects on the azimuth cut-off (λc) estimation. Then, the reliability of the λc estimation is analyzed by measuring the distance between the measured and fitted autocorrelation functions (ACFs). This analysis shows that it is of paramount importance to filter unfeasible/unreliable λc values. To identify those values in an objective way a criterion is proposed that is based on the χ2 test performed over a large dataset of Sentinel-1 SAR imagery. The effectiveness of the χ2 test is verified by correlating the accepted estimates against auxiliary significant wave height data.
Paraules clau: SAR, wind speed, azimuth cut-off, significant wave height.
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Rabosky D.L., J. Chang, P.O. Title, P.F. Cowman, L. Sallan, M. Friedman, K. Kaschner, C. Garilao, T. J. Near, M. Coll, M.E. Alfaro
Nature, 559, 392-395. DOI: 10.1038/s41586-018-0273-1 (BibTeX: rabosky.etal.2018b)
Resum: Veure
Far more species of organisms are found in the tropics than in temperate and polar regions, but the evolutionary and ecological causes of this pattern remain controversial1,2. Tropical marine fish communities are much more diverse than cold-water fish communities found at higher latitudes3,4, and several explanations for this latitudinal diversity gradient propose that warm reef environments serve as evolutionary ‘hotspots’ for species formation5,6,7,8. Here we test the relationship between latitude, species richness and speciation rate across marine fishes. We assembled a time-calibrated phylogeny of all ray-finned fishes (31,526 tips, of which 11,638 had genetic data) and used this framework to describe the spatial dynamics of speciation in the marine realm. We show that the fastest rates of speciation occur in species-poor regions outside the tropics, and that high-latitude fish lineages form new species at much faster rates than their tropical counterparts. High rates of speciation occur in geographical regions that are characterized by low surface temperatures and high endemism. Our results reject a broad class of mechanisms under which the tropics serve as an evolutionary cradle for marine fish diversity and raise new questions about why the coldest oceans on Earth are present-day hotspots of species formation.
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Fernández-Álvarez F.A.,
PhD thesis. Director/es: R. Villanueva. (BibTeX: fernandezalvarez.2018a)
Resum: Veure
Flying squids develop all its life cycle in the water column, as planktonic paralarvae and then as nektonic subadults and adults. In this Ph. D. Thesis, light was shed over several poorly understood aspects of the ontogeny and phylogeny of the Family Ommastrephidae. The mechanism of sperm migration from spermatangia to the female seminal receptacles was studied. Spermatozoa are able to actively migrate between both structures. The morphology of the hatchling of three Mediterranean ommastrephid species was studied based on embryos obtained by in vitro fertilization and a dichotomous key was develop to identify NE Atlantic species. The first feeding diet of paralarvae was assessed through laser-capture microdissection and DNA metabarcoding. The results indicate an ontogenetic shift from detritivorism to active predation. Molecular data indicate that the taxonomic name Ommastrephes bartramii actually hides four biological species. These advances in scientific knowledge have potential applications for a better understanding of the ecology, physiology, biodiversity and fishery science that will foster a deeper understanding of flying squids
Paraules clau: Ommastrephidae, ontogeny, phylogeny, sperm storage, paralarval morphology, first feeding of paralarvae, speciation, ontogenia, filogenia, almacenaje de esperma, morfología de paralarvas, primera dieta de paralarvas, especiación
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Oliveira Nunes S.,
PhD thesis. Director/es: M. Estrada i Miyares, M. Latasa Arcalís. Barcelona. (BibTeX: oliveiranunes.2018c)
Resum: Veure
Despite their small size, phytoplankton represents up to 50% ofthe global primary production of the Earthand serves as a connector between oceanic and atmospheric processes. Therefore, phytoplankton constitutes a central pillar in the comprehension of the cycles of mass and energy in the oceans. Their different attributes like size, abundance, community composition, functions, pigment complex and taxonomy provide relevant information to understand the processes of global change. In the past decades, the use of HPLC chromatography (High-Performance Liquid Chromatography) has proven as a very effective methodology to study marine phytoplankton. This technique, combined with the use of the statistic program CHEMTAX, allows to identify efficiently the contribution of certain taxonomic classes. This thesis is centered around the use of HPLC-CHEMTAX to identify the phytoplanktonic communities of three regions: the Mediterranean Sea, the Atlantic Ocean and the Antarctic Ocean, each characterized by different trophic conditions (from oligotrophic to eutrophic). With the results obtained, we expect to contribute to the comprehension of the local biochemical responses in a context of global change, as well as to improve future models of ecosystems and algorithms for remote sensing. To validate the data obtained, the results originated from the HPLC-CHEMOTAX were compared to other techniques used for identification and quantification, such as microscopy, flow cytometry and bio-optics. First, we focused on a temporal series (14 years) where we analyzed the seasonal and inter-annual dynamics of the phytoplanktonic community. We have verified that the phytoplanktonic community follows a seasonal pattern, just as had been observed in previous studies: diatoms dominated the blooms of late winter/early spring, while Synechococcusshowed maximum abundances during the months of April and August. The cryptophytes and dinoflagellates showed a positive response to sporadic fertilization events, associated mainly to stormy events. In the next study of this thesis, we analyzed the size fractions obtained from sequential filtrations by HPLC-CHEMTAX(total, n+m>3 μm and pico<3 μm) and we compared the results obtained with the algorithms proposed by Vidussi et al. (2001), Uitz et al. (2006) and Hirata et al. (2011). We also measured the specific absorption coefficient of phytoplankton and we compared it with size indicators. Our observations suggest that studies using size fractionation can inform about the sturcture of sizes of a community and that the absorption coefficient of phytoplankton is mainly associated with the pigment composition of the cells and the photoacclimation processes in different phytoplanktonic communities. Finally, with the aim of describing the diversity, abundance and physiologic characteristics of the phytoplanktonic community associated with the formation of marine aerosols, we have used the HPLC-CHEMOTAX in the Antarctic Ocean. Our study highlighted the association of cryptophytes in stratified surface waters influenced by ice fusion, the bloom of diatoms in South Georgia, an area rich in iron, as well as the substantial contributions of less studied groups such as the pelagophytes. In summary, this thesis shows the effectiveness of the HPLC-CHEMOTAX to study phytoplanktonic communities in varying ecological processes and environmental conditions. And in addition, the results obtained demonstrate that the HPLC-CHEMOTAX is also appropriate to quantify simultaneously different size classes of phytoplankton.
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Litaker R.W., S. Fraga, M. Montresor, M. Brosnahan, D.M. Anderson, M. Hoppenrath, J. Wolny, U. John, N. Sampedro, J. Larsen, A.J. Calado
Harmful Algae news, 61, 13-15. (BibTeX: litaker.etal.2018a)
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Tittensor D.P., T.D. Eddy, H.K. Lotze, E.D. Galbraith, W. Cheung, M. Barange, J.L. Blanchard, L. Bopp, A. Bryndum-Buchholz, M. Büchner, C. Bulman, D.A. Carozza, V. Christensen, M. Coll, J.P. Dunne, J.A. Fernandes, E.A. Fulton, A.J. Hobday, V. Huber, S. Jennings, M. Jones, P. Lehodey, J.S. Link, S. Mackinson, O. Maury, S.Niiranen, R. Oliveros-Ramos, T. Roy, J. Schewe, Y.-J. Shin, T. Silva, C.A. Stock, J. Steenbeek, P.J. Underwood, J. Volkholz, J.R. Watson, N.D. Walker
Geoscientific Model Development, 11, 1421-1442. DOI: 10.5194/gmd-11-1421-2018 (BibTeX: tittensor.etal.2018a)
Resum: Veure
Model intercomparison studies in the climate and Earth sciences communities have been crucial to building credibility and coherence for future projections. They have quantified variability among models, spurred model development, contrasted within- and among-model uncertainty, assessed model fits to historical data, and provided ensemble projections of future change under specified scenarios. Given the speed and magnitude of anthropogenic change in the marine environment and the consequent effects on food security, biodiversity, marine industries, and society, the time is ripe for similar comparisons among models of fisheries and marine ecosystems. Here, we describe the Fisheries and Marine Ecosystem Model Intercomparison Project protocol version 1.0 (Fish-MIP v1.0), part of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP), which is a cross-sectoral network of climate impact modellers. Given the complexity of the marine ecosystem, this class of models has substantial heterogeneity of purpose, scope, theoretical under-pinning, processes considered, parameterizations, resolution (grain size), and spatial extent. This heterogeneity reflects the lack of a unified understanding of the marine ecosystem and implies that the assemblage of all models is more likely to include a greater number of relevant processes than any single model. The current Fish-MIP protocol is designed to allow these heterogeneous models to be forced with common Earth System Model (ESM) Coupled Model Intercomparison Project Phase 5 (CMIP5) outputs under prescribed scenarios for historic (from the 1950s) and future (to 2100) time periods; it will be adapted to CMIP phase 6 (CMIP6) in future iterations. It also describes a standardized set of outputs for each participating Fish-MIP model to produce. This enables the broad characterization of differences between and uncertainties within models and projections when assessing climate and fisheries impacts on marine ecosystems and the services they provide. The systematic generation, collation, and comparison of results from Fish-MIP will inform an understanding of the range of plausible changes in marine ecosystems and improve our capacity to define and convey the strengths and weaknesses of model-based advice on future states of marine ecosystems and fisheries. Ultimately, Fish-MIP represents a step towards bringing together the marine ecosystem modelling community to produce consistent ensemble medium- and long-term projections of marine ecosystems.
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Stelzenmüller V., M. Coll, A. D. Mazaris, S. Giakoumi, S. Katsanevakis, M.E. Portman, R. Degen, P. Mackelworth, A. Gimpel, P.G. Albano, V. Almpanidou, J. Claudet, l, F. Essl, T. Evagelopoulos, J.J. Heymans, T. Genov, Salit Kark, F. Micheli, M.G. Pennino, G. Rilov, B. Rumes, J. Steenbeek, H. Ojaveer
Science of The Total Environment, 612, 1132-1140. DOI: 10.1016/j.scitotenv.2017.08.289 (BibTeX: stelzenmuller.etal.2018c)
Resum: Veure
Sperm storage is common in internally fertilizing animals, but is also present in several external fertilizers, such as many cephalopods. Cephalopod males attach sperm packets (spermatangia) to female conspecifics during mating. Females of eight externally fertilizing families comprising 25% of cephalopod biodiversity have sperm-storage organs (seminal receptacles) in their buccal area, which are not in direct physical contact with the deposited spermatangia. The mechanism of sperm transmission between the implantation site and the storage organ has remained a major mystery in cephalopod reproductive biology. Here, jumbo squid females covering almost the entire life cycle, from immature to a laboratory spawned female, were used to describe the internal structure of the seminal receptacles and the process of sperm storage. Seminal fluid was present between the spermatangia and seminal receptacles, but absent in regions devoid of seminal receptacles. The sperm cellular component was formed by spermatozoa and round cells. Although spermatozoa were tracked over the buccal membrane of the females to the inner chambers of the seminal receptacles, round cells were not found inside the seminal receptacles, suggesting that spermatozoa are not sucked up by the muscular action of the seminal receptacles. This finding supports the hypothesis that spermatozoa are able to actively migrate over the female skin. Although further experimental support is needed to fully confirm this hypothesis, our findings shed light on the elusive process of sperm storage in many cephalopods, a process that is fundamental for understanding sexual selection in the sea.
Paraules clau: Risk management process, science-policy interface, standardized framework, terminology, tools, uncertainty
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Belmonte M., I. Otosaka, A. Stoffelen, A. Verhoef
The Cryosphere, 12, 2941–2953. DOI: 10.5194/tc-12-2941-2018 (BibTeX: belmonte.etal.2018)
Resum: Veure
This paper presents the first long-term climate datarecord of sea ice extents and backscatter derived from inter-calibrated satellite scatterometer missions (ERS, QuikSCATand ASCAT) extending from 1992 to the present date (Ver-hoef et al., 2018). This record provides a valuable indepen-dent account of the evolution of Arctic and Antarctic seaice extents, one that is in excellent agreement with the pas-sive microwave records during the fall and winter months butshows higher sensitivity to lower concentration and meltingsea ice during the spring and summer months. The scatterom-eter record also provides a depiction of sea ice backscat-ter at C- and Ku-bands, allowing the separation of seasonaland perennial sea ice in the Arctic and further differentia-tion between second-year (SY) and older multiyear (MY) iceclasses, revealing the emergence of SY ice as the dominantperennial ice type after the historical sea ice loss in 2007 andbearing new evidence on the loss of multiyear ice in the Arc-tic over the last 25 years. The relative good agreement be-tween the backscatter-based sea ice (FY, SY and older MY)classes and the ice thickness record from Cryosat suggests itsapplicability as a reliable proxy in the historical reconstruc-tion of sea ice thickness in the Arctic
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Salvador Font-Muñoz J., A. Jordi, S. Anglès, P. Ferriol, E. Garcés, G. Basterretxea
Marine Ecology Progress Series, 594, 51-63. DOI: 10.3354/meps12559 (BibTeX: salvadorfontmunoz.etal.2018)
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Yang X., V. Corcione, F. Nunziata, M. Portabella, M. Migliaccio, A. Mouche
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Valencia, Spain, 22-27 July, 2018., . (BibTeX: yang.etal.2018)
Resum: Veure
Typhoon is one of the most powerful and destructive natural disasters. Accurate forecasting of Typhoon track and intensity is very important to disaster prevention and reduction. Satellite observations can effectively compensate for the shortcomings of traditional methods of sea surface measurement and provide all-weather observation over the sea surface, which is of great significance to improve the numerical prediction of strong convective weather over ocean. The spaceborne radar observes the backscattering caused by the sea surface roughness, and then, the sea surface wind can be retrieved. The Synthetic Aperture Radar (SAR) is an important data source for sea surface monitoring. A variety of meteorological hydrological elements can be retrieved by SAR observation, and it has been used in data assimilation in recent years [1]. SAR imagery is also used to monitor strength and structure of typhoons [2]. The accuracy of sea surface winds retrieved from SAR has been found to be comparable to that of scatterometer data [3], and these wind fields can be used with a data assimilation system to provide the initial conditions for the numerical weather prediction (NWP) model [4]. In this study, a data assimilation scheme is proposed to assimilate the Sentinel-1 SAR retrieved winds in the Weather Research and Forecasting (WRF) model. Numerical simulation experiments of the typhoon Lionrock (2016) and hurricane Hermine (2016) are conducted to test and compare different data assimilation methods.
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Tilves U., A. Sabatés, M. Blázquez, V. Raya, V.L. Fuentes
Marine Biology, 165, 127. DOI: 10.1007/s00227-018-3381-4 (BibTeX: tilves.etal.2018c)
Resum: Veure
Fish–jellyfish associations were studied close to Barcelona (NW Mediterranean) during the summer period from 2008 to 2014. Jellyfish and their associate juvenile fish were collected, identified, counted, and measured. Fish behaviour was described by visual field observations and laboratory experiments were performed to determine the survival of the associated fish after being in contact with the jellyfish. In addition, the possible contribution of jellyfish to the dietary composition of the fish was assessed using a combination of biomarkers. Trachurus mediterraneus, Trachurus trachurus, and Caranx rhonchus were associated with the jellyfish Rhizostoma pulmo and Cotylorhiza tuberculata. Trachurus mediterraneus was the most frequent species and their size during the association ranged between 8.4 and 66 mm standard length. The size and number of T. mediterraneus were slightly correlated with the size of R. pulmo, but not with that of C. tuberculata, although more numerous fish were found swimming with C. tuberculata. Behaviour studies showed that juvenile fish swam around jellyfish and into their oral arms seeking shelter without suffering any pain. This survival capability was corroborated by experimental work in which all the specimens of T. mediterraneus survived after being in contact with both jellyfish species. Stable isotopes and fatty acids also revealed an important contribution of R. pulmo and C. tuberculata to T. mediterraneus diet. Defining better the associations between jellyfish and juvenile fish will help to understand the effects of the association on the survival and recruitment of fish species potentially ecologically and economically relevant.
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Gori A., I. Tolosa, C. Orejas, L. Rueda, N. Viladrich, J. Grinyó, S. Flögel, R. Grover, C. Ferrier-Pagès
Deep-Sea Research. Part I: Oceanographic Research Papers, 141, 106-117. DOI: 10.1016/j.dsr.2018.08.010 (BibTeX: gori.etal.2018)
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De La Hoz M.V., F. Sardà, M. Coll, R. Sáez, A. Mechó, F. Oliva, M. Ballesteros, I. Palomera
Regional Studies in Marine Science, 19, 47-68. DOI: 10.1016/j.rsma.2018.03.002 (BibTeX: delahoz.etal.2018a)
Resum: Veure
We evaluated seasonal patterns of biodiversity of the megabenthic non-crustacean invertebrates on soft bottoms of the continental shelf and slope of the Catalan Sea (Balearic Sea, Northwestern Mediterranean). Scientific demersal trawls were carried out between 30 and 400 m during winter and summer of 2013 in 37 and 45 stations respectively. Among a total of 188 species, a limited number of echinoderms, cephalopods and occasionally ascidians dominated the bulk of the community, covering up to 95% of the total wet weight. Seasonal and bathymetric variations were found in the different biodiversity patterns, with higher values in summer and in shallower depths, regarding overall wet weight (>14,000 kg/km2), density (>1 million ind/km2), richness and diversity (143 species; H’=1.74). The statistical differences in density and wet weight between bathymetric strata reflected in particular groups of species typifying each environment, but without any exclusiveness in depth preferences, since generalist species were the main components of the community. Depth was the main driver of statistical differences in the community structure, but a combined influence of geographic location was also identified from an interaction effect. Sediment type may be influencing habitat preferences, with echinoderms (especially crinoids Leptometra and Antedon), dominating on sandy substrates, and cephalopod mollusks (especially cephalopods Illex, Eledone, Octopus) dominating on muddy substrates. Trawling activity may also influence the dominance of some target and non-target species. Several infrequent bivalves, opistobranchs and species from phyla Porifera, Cnidaria, Bryozoa and Sipuncula constituted an important understudied component of the richness of this community. This is the first study dealing with bathymetric variation of the megabenthic non-crustacean community of the Catalan Sea within this gradient of depths above the middle slope and also considering seasonal variability.
Paraules clau: Richness; Density; Wet weight; Megabenthic invertebrates; Continental shelves; Upper slope; Spain; Catalonia; N-W Mediterranean; Balearic basin; 39°54’ 07”- 41°11’ 00”lat N; 00°01’ 07” - 01°54’ 27” long E
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Mačić V., P.G. Albano, V. Almpanidou, J. Claudet, X. Corrales, F.Essl, A. Evagelopoulos, I. Giovos, C. Jimenez, S. Kark, O. Marković, A.D. Mazaris, G.Á. Ólafsdóttir, M. Panayotova, S. Petović, W. Rabitsch, M. Ramdani, G. Rilov, E. Tricarico, T. Vega Fernández, M. Sini, V. Trygonis, S. Katsanevakis
Frontiers in Marine Science, 5, 178. DOI: 10.3389/fmars.2018.00178 (BibTeX: mai.etal.2018b)
Resum: Veure
Biological invasions threaten biodiversity in terrestrial, freshwater and marine ecosystems, requiring substantial conservation and management efforts. To examine how the conservation planning literature addresses biological invasions and if planning in the marine environment could benefit from experiences in the freshwater and terrestrial systems, we conducted a global systematic review. Out of 1,149 scientific articles mentioning both “conservation planning” and “alien” or any of its alternative terms, 70 articles met our selection criteria. Most of the studies were related to the terrestrial environment, while only 10% focused on the marine environment. The main conservation targets were species (mostly vertebrates) rather than habitats or ecosystems. Apart from being mentioned, alien species were considered of concern for conservation in only 46% of the cases, while mitigation measures were proposed in only 13% of the cases. The vast majority of the studies (73%) ignored alien species in conservation planning even if their negative impacts were recognized. In 20% of the studies, highly invaded areas were avoided in the planning, while in 6% of the cases such areas were prioritized for conservation. In the latter case, two opposing approaches led to the selection of invaded areas: either alien and native biodiversity were treated equally in setting conservation targets, i.e., alien species were also considered as ecological features requiring protection, or more commonly invaded sites were prioritized for the implementation of management actions to control or eradicate invasive alien species. When the “avoid” approach was followed, in most of the cases highly impacted areas were either excluded or invasive alien species were included in the estimation of a cost function to be minimized. Most of the studies that followed a “protect” or “avoid” approach dealt with terrestrial or freshwater features but in most cases the followed approach could be transferred to the marine environment. Gaps and needs for further research are discussed and we propose an 11-step framework to account for biological invasions into the systematic conservation planning design.
Paraules clau: Invasive alien species, Management actions, Mitigation, Non-indigenous species, Systematic conservation planning
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Purroy A., M. Najdek, E. Isla, I. Župan, J. Thébault, M. Peharda
Marine Environmental Research, 142, 234-249. DOI: 10.1016/j.marenvres.2018.10.011 (BibTeX: purroy.etal.2018a)
Resum: Veure
The trophic ecology of two bivalves, the clam Callista chione and the cockle Glycymeris bimaculata was studied using environmental and biochemical variables of the suspended particulate matter and the sediment. Samples were collected from two shallow sites, Pag and Cetina, in the coastal oligotrophic Mediterranean Sea, during a 17 month period. The temporal variation of the particulate matter reflected a mixture between marine and terrestrial sources throughout the year, with a clear marine influence during summer and fall, and predominance of terrestrial inputs during spring and winter. The digestive gland was a useful rapid turnover tissue, where the carbon isotope signal was species-specific and the nitrogen isotope one was site-specific. FA markers in the digestive gland revealed a mixed diet where Callista chione fed more upon fresh material than G. bimaculata which relied largely on bacteria-derived detritus. Overall, little feeding niche overlap was observed between the two species during the year, indicating resource partitioning, expected for a food-limited system. The present trophic ecology study in co-occurring species allowed identifying species-specific feeding adaptations to environmental variability.
Paraules clau: Feeding ecology; Bivalves; Suspension feeder; Biochemical variables; Stable isotopes; Fatty acids; Adriatic sea; Niche partitioning; Coastal ecosystems
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Suffridge C.P., L. Gómez‐Consarnau, D.R. Monteverde, L. Cutter, J. Arístegui, X.A. Alvarez‐Salgado, J.M. Gasol, S.A. Sañudo‐Wilhelmy
Journal of Geophysical Research-Biogeosciences, 123, 9, 2890-2907. DOI: 10.1029/2018JG004554 (BibTeX: suffridge.etal.2018)
Resum: Veure
Determining the factors that influence marine microbial growth and community structure are critical for the understanding of global carbon cycling. Since the early twentieth century, it has been known that B vitamins play an important role in phytoplankton community dynamics. Limited oceanic dissolved B vitamin distributions indicate that these important coenzymes are present at picomolar levels, which could be too low to support maximal phytoplankton growth, and vast regions of the ocean exist where they are undetectable. Despite their importance, particulate B vitamin concentrations of field microbial populations are unknown. Here we report B vitamin concentrations measured in both the particulate and dissolved fractions, including multiple biochemically relevant B vitamin congeners. We establish their spatial distributions spanning distinct biogeographic and oceanographic regimes in the Mediterranean Sea and the Eastern Atlantic Ocean and show that all congeners are present both dissolved in seawater and in suspended particles. We observe that B vitamins cooccur in patches defined by regional biogeographic and oceanographic features. Additionally, distinct patterns of congener relative abundance in the dissolved and particulate pools provide insight to biological and chemical cycling of these compounds between and within the dissolved and particulate pools. Finally, linear model results demonstrate that model fits of microbial assemblages are strongest when they include both inorganic nutrients and dissolved B vitamin concentrations. We believe that these findings represent an advance in our understanding of B vitamin oceanographic distributions and point to interesting hypotheses of their influence on marine microbial ecology.
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Lange R., M. Dall’Osto, H. Skov, J.K. Nøjgaard, I.E. Nielsen, I.E., Beddows, R. Simó, R.M. Harrison, A. Massling
Atmospheric Environment, 183, 1-10. DOI: 10.1016/j.atmosenv.2018.03.060 (BibTeX: lange.etal.2018)
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Cramer W., J. Guiot, M. Fader, J. Garrabou, J.-P. Gattuso, A. Iglesias, M.A. Lange, P. Lionello, M.C. Llasat, S. Paz, J. Peñuelas, M. Snoussi, A. Toreti, M.N. Tsimplis, E. Xoplaki
Nature Climate Change, 8, 972-980. DOI: 10.1038/s41558-018-0299-2 (BibTeX: cramer.etal.2018)
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Rigual-Hernández A.S., J.A. Flores, F.J. Sierro, M.A. Fuertes, L. Cros, T.W. Trull
Biogeosciences, 15, 1843-1862. DOI: 10.5194/bg-15-1843-2018 (BibTeX: rigualhernandez.etal.2018)
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Reza Rastgoo A., J. Navarro2, T. Valinassab
Aquatic Biology, 27, 35-41. DOI: 10.3354/ab00694 (BibTeX: rezarastgoo.etal.2018a)
Resum: Veure
Documenting the interactions and mechanisms of coexistence among predators is important for understanding their ecological roles in food webs. Here, we examined the diet and trophic relationships of 6 demersal batoids coexisting in the Gulf of Oman by analyzing stomach contents. There were significant differences in diets among the batoid species, suggesting differential preferences. Diets of Gymnura poecilura and Torpedo sinuspersici were similar and consisted mostly of teleost fishes. In contrast, Brevitrygon walga and Rhinobatos punctifer mostly ate crustaceans. The diets of Maculabatis randalli and Pastinachus sephen were diverse and included crustaceans, teleosts, polychaetes, bivalves and echinoderms. The differences in diet among these batoids may be related to morphological differences in feeding structures and to differences in behavior, which could explain their diversity and coexistence in the Gulf of Oman
Paraules clau: Elasmobranch; Foraging ecology; Diet; Gulf of Oman
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Mangot J.F., I. Forn, A. Obiol, R. Massana
Environmental Microbiology, 20, 10, 3876-3889. DOI: 10.1111/1462-2920.14408 (BibTeX: mangot.etal.2018)
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Guerrero Q., J. Guillén, R. Durán, R. Urgeles
Marine Geology, 395, 219-233. DOI: 10.1016/j.margeo.2017.10.002 (BibTeX: guerrero.etal.2018a)
Resum: Veure
A sand ridge field located over a retreating deltaic lobe in the Ebro Delta (NW Mediterranean) is characterized using three sets of co-located multibeam bathymetric data acquired in 2004, 2013 and 2015, measurements of near-bottom currents, high-resolution seismic profiles, and aerial photographs. The aim of this study is to illustrate the processes and timing involved in the initial stages of sand ridge development. The sand ridge field extends from the 5 to 15 m isobaths and the ridges have maximum heights and wavelengths of 2.5 and 400 m, respectively; they have straight crests that are arranged obliquely to the shoreline and are composed of fine sand. In general, the sand ridges are symmetric, although asymmetries with the lee side of the ridge facing to the SE and to the NW are also present. The genesis of the sand ridge field is closely related to the contemporary evolution of the Ebro River mouth. The change of the main river channel in the 1940s led to progressive abandonment of the former river mouth and to severe coastal retreatment (~ 37 m·yr− 1), making large amounts of sediment available for ridge formation. The persistent Mistral winds (NW) induce near-bottom currents flowing towards the SE, which are able to rework and transport sandy sediments. The sand ridges are currently active, with mean SE migration rates of ~ 10 m·yr− 1 most likely in pulses, when high-speed currents occur. Wave-storm events induce reverse flows (E-SE), which reshape the ridges to symmetric or opposite asymmetry geometries. The bedform morphologies, the oblique arrangement with respect to the shoreline, the angle between the strongest current and the crestlines and the sediment grain size match well with those of shoreface-connected (attached) sand ridges and, particularly, with the initial stages of sand ridge development on storm-dominated continental shelves. Sediment availability, shoreline retreat, relatively strong near-bottom currents induced by winds, seafloor irregularities and relative sea-level rise on the Ebro Delta combine to provide a suitable transgressive environment for sand ridge development. Time-scales related to sand ridges are usually of hundreds/thousands of years, but here it is demonstrated that the genesis of sand ridges can take place within a few decades. The studied bedforms are unlikely to persist in the absence of rapid sea-level rise, leading to sediment scarcity and wave and current reworking.
Paraules clau: Ebro Delta, Coastal erosion, Shelf processes, Shoreface connected sand ridge, Morphodynamics, Bedform
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Durán R., J. Guillén
In: Submarine Geomorphology, Ed. A. Micallef, S. Krastel, A. Savini. Springer. 185-206. DOI: 10.1007/978-3-319-57852-1_11 ISBN: 978-3-319-57851-4 (BibTeX: duran.guillen.2018a)
Resum: Veure
Continental shelves comprise the zone adjacent to the continents, extending from the infralittoral to a marked change in slope known as the shelf break. The shelf break is located at a variable depth from 20 to 550 m, with a global average depth of 140 m. They develop in passive and active margins and can be dominated by different processes, which include tides, waves and currents. The present day geomorphology of the continental shelf comprises a wide variety of modern and relict features as a result of different controlling factors—geological structure, sea-level change, and sediment delivery and dispersal systems—acting at varying time scales. This chapter illustrates the most common landforms observed in siliciclastic continental shelves, with special attention to the processes that generate them. Landforms include consolidated bottoms, erosive morphologies, prograding landforms, bedforms, gas-related morphologies and anthropogenic features.
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Torres A.P., P. Reglero, M. Hidalgo, P. Abelló, D.S. Simão, F. Aleman, E. Massutí, A. Dos Santos
Hydrobiologia, 808, 1, 137-152. DOI: 10.1007/s10750-017-3414-x (BibTeX: torres.etal.2018a)
Resum: Veure
In marine ecosystems, the most significant migration observed in terms of biomass distribution is the one connected with the vertical movements in the water column. In the present study, the vertical profiles of the mesopelagic shrimps Gennadas elegans, Eusergestes arcticus, Sergia robusta, and the epipelagic Parasergestes vigilax in the Balearic Sea (western Mediterranean), during the stratified (summer) and non-stratified (autumn) hydrographic conditions, were investigated through their ontogeny, from the larval to adult stages. The mesopelagic adults were observed to move down to the deeper layers during the night more than during the daylight hours. Most larvae aggregated within the limits of the upper water column. The P. vigilax larvae were collected only during the stratified period. The first two larval stages vertical distribution indicates that the mesopelagic crustacean spawning could occur at greater depths. During the non-stratified period, the larvae of the mesopelagic species tended to remain at about 500 m depth at night, rising towards the upper layers at sunrise. Vertical patterns are discussed, as strategies associated with predator–prey trade-offs. To our knowledge, the present study is the first such attempt to jointly analyze the vertical migrations of the developmental stages of the pelagic shrimps in the Mediterranean Sea
Paraules clau: Shrimps, Ontogeny, Diel vertical distribution, Larvae, Mediterranean
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von Schuckmann K., P.Y. Le Traon, N. Smith, A. Pascual, P. Brasseur, K. Fennel, S. Djavidnia, S. Aaboe, E. Alvarez-Fanjul, E. Autret, L. Axell, R. Aznar, M. Benincasa, A. Bentamy, F. Boberg, R. Bourdallé-Badie, B. Buongiorno-Nardelli, V.E. Brando, C. Bricaud, L.A. Breivik, R.J.W. Brewin, A. Capet, A. Ceschin, S. Ciliberti, G. Cossarini, M. de Alfonso, A. de Pascual-Collar, J. de Kloe, J. Deshayes, C. Desportes, M. Drévillon, Y. Drillet, R. Droghei, C. Dubois, O. Embury, H. Etienne, C. Fratianni, J. García-Lafuente, M. García-Sotillo, G. Garric, F. Gasparin, R. Gerin, S. Good, J. Gourrion, M. Grégoire, E. Greiner, S. Guinehut, E. Gutknecht, F. Hernandez, O. Hernandez, J. Hoyer, L. Jackson, S. Jandt, S. Josey, M. Juza, J. Kennedy, Z. Kokkini, G. Korres, M. Kouts, P. Lagemaa, T. Lavergne, B. le Cann, J.F. Legeais, B. Lemieux-Dudon, B. Levier, V. Lien, I. Maljutenko, F. Manzano, M. Marcos, V. Marinova, S. Masina, E. Mauri, M. Mayer, A. Melet, F. Mélin, B. Meyssignac, M. Monier, M. Müller, S. Mulet, C. Naranjo, G. Notarstefano, A. Paulmier, B. Pérez-Gomez, I. Pérez-Gonzalez, E. Peneva, C. Perruche, K.A. Peterson, N. Pinardi, A. Pisano, S. Pardo, P.M. Poulain, R.P. Raj, U. Raudsepp, M. Ravdas, R. Reid, M.H. Rio, S. Salon, A. Samuelsen, M. Sammartino, S. Sammartino, A. Britt-Sando, R. Santoleri, S. Sathyendranath, J. She, S. Simoncelli, C. Solidoro, A. Stoffelen, A. Storto, T. Szerkely, S. Tamm, S. Tietsche, J. Tinker, J. Tintore, A. Trindade, D. van Zanten, L. Vandenbulcke, A. Verhoef, N. Verbrugge, L. Viktorsson, K. von Schuckmann, S.L. Wakelin, A. Zacharioudaki, H. Zuo
Journal of Operational Oceanography, 11, sup1, S1-S142. DOI: 10.1080/1755876X.2018.1489208 (BibTeX: vonschuckmann.etal.2018)
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Basterretxea G., F.J. Torres-Serra, E. Alacid, S. Anglès, J. Camp, I. Ferrera, E. Flo, J.S. Font-Muñoz, A. Jordi, A. Reñé, P.M. Salgado-Hernanz, N. Sampedro, E. Garcés
Frontiers in Marine Science, 5, 78, 1-13. DOI: 10.3389/fmars.2018.00078 (BibTeX: basterretxea.etal.2018)
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Ventura T., F. Palero, G. Rotllant, Q.P. Fitzgibbon
Hydrobiologia, 825, 1, 47-60. DOI: 10.1007/s10750-017-3445-3 (BibTeX: ventura.etal.2018a)
Resum: Veure
Metamorphosis involves a complex network of genes that orchestrate a perfectly timed reorganization of one body form to another. The molecular pathways that start to unravel for an increasing number of species show that there exists great diversity among different species, as would be expected by their wide range of life histories and transformation strategies. The metamorphosis process could account for a considerably high percentile of transcribed sequences over a short period of time, with the genome encoding for different life forms. Such important changes in expression patterns for a high number of genes pose a challenge for accurately assign each gene to a function. Several key conserved factors are consistently expressed and can be placed at the center of metamorphosis, including the mechanisms involving the molt hormone, 20 Hydroxy-Ecdysone, and the juvenile hormone. Yet, many additional factors are not characterized, remain unannotated, or do not have a function assigned. This manuscript provides several examples of how an integrated omics approach can develop further insights into crustacean metamorphosis and eventually lead to discovery of key factors for metamorphosis.
Paraules clau: Metamorphosis; Ecdysone; Juvenile hormone; Cytochrome P450; Omics
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Druet M., A. Muñoz‐Martín, J.L. Granja‐Bruña, A. Carbó‐Gorosabel, J. Acosta, P. Llanes, G. Ercilla
Tectonics, 37, 5, 1576-1604. DOI: 10.1029/2017TC004903 (BibTeX: druet.etal.2018c)
Resum: Veure
The magma‐poor rifted continental margin of Galicia has an extremely complex structure. Its formation involved several rifting episodes that occurred ultimately during the early Cretaceous near a ridge triple junction, which produced a change in the orientation of the main structures in its transition to the north Iberia margin. In addition, there is a superimposed partial tectonic inversion along its northwest and northern border which developed from the Late Cretaceous to at least Oligocene times. The present study integrates a large volume of new geophysical information (mainly marine gravity data and 2D seismic reflection profiles) to provide insights on the formation of this rift system and on the development of its later inversion. The combined interpretation and modeling of this data enable the presentation of a new crustal and structural domains map for the whole Galicia margin. This includes the rift domains related to the extreme thinning of the crust and the lithospheric mantle (stretched, necking, and hyperextension and mantle exhumation (HME) domains), as well as a domain of intense compressional deformation. New constraints arise on the origin, the deep structure, and the characterization of the along‐ and across‐strike variation of the continent‐ocean transition of the margin, where a progressive change from hyperextension to partial inversion is observed. The development of both rifting and later partial tectonic inversion is influenced by the existence of former first‐order tectonic features. Most of the tectonic inversion is focused on the HME domain, which in some areas of the northwestern margin is completely overprinted by compressional deformation
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Sebastián M., J.C. Auguet, C. Restrepo-Ortiz, M.M. Sala, C. Marrasé, J.M. Gasol
Environmental Microbiology, 20, 2, 713-723. DOI: 10.1111/1462-2920.14002 (BibTeX: sebastian.etal.2018a)
Resum: Veure
The bathypelagic ocean is one of the largest ecosystems on Earth and sustains half of the ocean's microbial activity. This microbial activity strongly relies on surface-derived particles, but there is growing evidence that the carbon released through solubilization of these particles may not be sufficient to meet the energy demands of deep ocean prokaryotes. To explore how bathypelagic prokaryotes respond to the absence of external inputs of carbon, we followed the long-term (1 year) dynamics of an enclosed community. Despite the lack of external energy supply, we observed a continuous succession of active prokaryotic phylotypes, which was driven by recruitment of taxa from the seed bank (i.e., initially rare operational taxonomic units [OTUs]). A single OTU belonging to Marine Group I of Thaumarchaeota, which was originally rare, dominated the microbial community for ∼ 4 months and played a fundamental role in this succession likely by introducing new organic carbon through chemolithoautotrophy. This carbon presumably produced a priming effect, because after the decline of Thaumarchaeota, the diversity and metabolic potential of the community increased back to the levels present at the start of the experiment. Our study demonstrates the profound versatility of deep microbial communities when facing organic carbon deprivation
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Sturm U., S. Schade, L. Ceccaroni, M. Gold, C.C.M. Kyba, B. Claramunt, M. Haklay, D. Kasperowski, A. Albert, J. Piera, J. Brier, C. Kullenberg, S. Luna
RIO Research Ideas and Outcomes, 4, DOI: 10.3897/rio.4.e23394 (BibTeX: sturm.etal.2018a)
Resum: Veure
Apps for mobile devices and web-based platforms are increasingly used in citizen science projects. While extensive research has been done in multiple areas of studies, from Human-Computer Interaction to public engagement in science, we are not aware of a collection of recommendations specific for citizen science that provides support and advice for planning, design and data management of mobile apps and platforms that will assist learning from best practice and successful implementations. In two workshops, citizen science practitioners with experience in mobile application and web-platform development and implementation came together to analyse, discuss and define recommendations for the initiators of technology based citizen science projects. Many of the recommendations produced during the two workshops are applicable to citizen science project that do not use mobile devices to collect data. Therefore, we propose to closely connect the results presented here with ECSA’s Ten Principles of Citizen Science.
Paraules clau: Citizen science; Digital technologies; Design; Reuse; Interoperability; Sustainability
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Grieco G., A. Stoffelen, M. Portabella
Proc. of the 2018 EUMETSAT Meteorological Satellite Conference, Tallinn, Estonia, 17-21 September, 2018., . (BibTeX: grieco.etal.2018)
Resum: Veure
The impact of specular point location estimate inaccuracies on satellite delay-Doppler map (DDM) observed distortions is assessed in this paper. A set of raw reflected Global Navigation Satellite System (GNSS-R) echoes acquired by the satellite constellation Cyclone GNSS (CYGNSS) during hurricanes Irma and Harvey has been recompressed by progressively reducing the Doppler frequency inaccuracy at the specular point. The results show that recompressing raw echoes with highly accurate specular point location estimates strongly reduces the DDM distortions.
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Serrano i Gras E.,
PhD thesis. Director/es: M. Ribes, R. Coma. Barcelona. (BibTeX: serranoigras.2018a)
Resum: Veure
Shallow-water rocky ecosystems in temperate areas are dominated by macroalgae, whilst zooxanthellate corals are extremely rare. In an era of global change, sea warming plays a crucial role in the widespread phase shifts from coral- to algal-dominance in tropical coral reef ecosystems, and in the poleward spread and increase in abundance of some tropical and subtropical zooxanthellate corals into algal-dominated temperate areas. In the Mediterranean Sea, the zooxanthellate coral Oculina patagonica (Scleractinia, Oculinidae) is experiencing a range-expanding process, providing a good case study to examine how zooxanthellate corals can affect the structure of temperate ecosystems. In this PhD Thesis, different field studies were performed along the Iberian coast in the western Mediterranean to examine the demographics and population ecology of O. patagonica and contribute understanding the interaction among the main intrinsic and extrinsic factors in modulating the species’ dynamics. First, we document that O. patagonica is experiencing an invasive behavior that challenges the current conceptual framework of shallow-water rocky ecosystems, by providing evidence that the species is able to: i) form encrusting bioconstructions and drive a phase shift from macroalgal- to coral-dominated states, and ii) experience an invasive behavior at both population outbreak and geographical distribution range levels. Second, over a ~4-yr field experiment we document that a severe and recurrent pattern of partial mortality on O. patagonica colonies occurs under low seawater temperature (ST) conditions during winter, which appears to play a crucial role in constraining the growth dynamics of the species at the high-latitude area in the north-eastern Iberian coast. Third, we document the spatial variation in the demographics of O. patagonica (occurrence, density, cover, colony partial mortality and size-structure) by examining 314 locations along ~1300 km Iberian coast that provides a detailed baseline quantitative dataset. We found that the colony size-structure of coral populations in natural locations were unimodal and positively skewed, indicative of non-stable and growing populations. However, the species’ demographics showed a marked ‘abundant-center’ pattern that is not only related to the time of establishment but also to the relevant role of differences in coral population growth that correlate with key environmental variables. Finally, we layered our broad spatial scale observations on the demographics of O. patagonica, together with our and previous empirical and experimental studies on the interaction between biological traits and key environmental factors modulating coral performance, to identify the potential causes of the geographic range structure and invasion behavior of this species within the Iberian coast. The success of O. patagonica colonies and populations on natural locations appear to be generally constrained by low ST and light conditions, with thresholds that limit coral growth of mean annual photosynthetic active radiation at 3 m depth <30 mol photons m-2 d-1, mean ST <19ºC, percentile 10th-ST <14ºC and percentile 90th-ST <25ºC, but without severe high-ST periods (percentile 90th-ST >27ºC). In addition, the high availability of open space for O. patagonica to colonize, and the positive effects of sand scouring and sea urchin herbivory on coral population growth, indicate that open space availability is a crucial factor enhancing the proliferation of the species within the Iberian coast. We also found that artificial reefs foster the population growth and the expansion of the distributional range of this coral species. The broad spread of O. patagonica across the Mediterranean Sea, and its invasive behavior at both distributional range shift and population outbreak levels, able to drive phase shifts from macroalgae to coral dominance in natural and artificial reefs, is consistent with the ongoing process of zooxanthellate coral-mediated tropicalization of shallow-water rocky ecosystems documented in other subtropical and temperate areas under current global change.
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Abelló P., F. Maynou
Arxius de Miscel·lània zoològica, 16, 213-219. (BibTeX: abello.maynou.2018a)
Resum: Veure
A population of the poorly-known stomatopod crustacean, Pseudosquillopsis cerisii, was detected in the NW Mediterranean Sea. To date, in Mediterranean waters, this species was only known from rare reports that were mainly based on the occurrence of single individuals. Analysis of the stomach contents of fish predators caught in coastal trammel-net artisanal fisheries revealed several individuals of this species on a sandy bottom with nearby Posidonia seagrass beds in an area within the vicinity of Vilanova i la Geltrú (Catalonia). This is the first report of the species from Iberian peninsula waters.
Paraules clau: Pseudosquillopsis cerisii; Biogeography; Mediterranean; Occurrence; Population: Record; Biogeografía; Mediterráneo; Presencia; Población; Registro
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Luna S., M. Gold, A. Albert, L. Ceccaroni, B. Claramunt, O. Danylo, M. Haklay, R. Kottmann, C. Kyba, J. Piera, A. Radicchi, S. Schade, U. Sturm
In: Multimedia Tools and Applications for Environmental & Biodiversity Informatics., Ed. A. Joly, S. Vrochidis, K. Karatzas, A. Karppinen, P. Bonnet. Springer. Chap. 2. 9-30. DOI: 10.1007/978-3-319-76445-0_2 ISBN: 978-3-319-76445-0 (BibTeX: luna.etal.2018a)
Resum: Veure
The functionality available on modern ‘smartphone’ mobile devices, along with mobile application software and access to the mobile web, have opened up a wide range of ways for volunteers to participate in environmental and biodiversity research by contributing wildlife and environmental observations, geospatial information, and other context-specific and time-bound data. This has brought about an increasing number of mobile phone based citizen science projects that are designed to access these device features (such as the camera, the microphone, and GPS location data), as well as to reach different user groups, over different project durations, and with different aims and goals. In this chapter we outline a number of key considerations when designing and developing mobile applications for citizen science, with regard to (1) interoperability and data standards, (2) participant centred design and agile development, (3) user interface & user experience design, and (4) motivational factors for participation.
Paraules clau: Mobile Apps; Citizen science; Metadata data standard re-use
Piredda R., J.M. Claverie, J. Decelle, C. de Vargas, M. Dunthorn, B. Edvardsen, W. Eikrem, D. Forster, W.H.C.F. Kooistra, R. Logares, R. Massana, M. Montresor, F. Not, H. Ogata, J. Pawlowski, S. Romac, D. Sarno, T. Stoeck, A. Zingone
Scientific Reports, 8, 18059, 1 - 12. DOI: 10.1038/s41598-018-36345-9 (BibTeX: piredda.etal.2018)
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Sampedro N.,
PhD thesis. Director/es: J. Camp. Barcelona. (BibTeX: sampedro.2018a)
Resum: Veure
El fitoplàncton és el conjunt d’organismes microscòpics i majoritàriament fotosintètics que viuen suspesos en els ecosistemes aquàtics. Comprèn diversos tipus d'organismes unicel·lulars, tant procariotes (bacteris) com eucariotes (protistes). Els grups més importants que inclou serien les diatomees, les dinoflagel·lades, les haptofícies i els cianobacteris. El fitoplàncton és la base de la xarxa tròfica marina, donat que és els responsable de la major part de la producció primària dels oceans. Utilitza l'energia solar i aigua amb nutrients per fixar el diòxid de carboni (CO2) en matèria orgànica i alliberar oxigen (O2). D’aquesta manera proveeixen d’aliment a nivells tròfics superiors, contribueixen a la captació de CO2 de l’atmosfera i a la producció d’oxigen, fet pel qual la seva funció és vital no només pels ecosistemes marins sinó per tot el planeta. [...]
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Romera-Castillo C., M. Pinto, T.M. Langer, X.A. Álvarez-Salgado, G.J. Herndl
Nature Communications, 9, 1430, DOI: 10.1038/s41467-018-03798-5 (BibTeX: romeracastillo.etal.2018)
Resum: Veure
Approximately 5.25 trillion plastic pieces are floating at the sea surface. The impact of plastic pollution on the lowest trophic levels of the food web, however, remains unknown. Here we show that plastics release dissolved organic carbon (DOC) into the ambient seawater stimulating the activity of heterotrophic microbes. Our estimates indicate that globally up to 23,600 metric tons of DOC are leaching from marine plastics annually. About 60% of it is available to microbial utilization in less than 5 days. If exposed to solar radiation, however, this DOC becomes less labile. Thus, plastic pollution of marine surface waters likely alters the composition and activity of the base of the marine food webs. It is predicted that plastic waste entering the ocean will increase by a factor of ten within the next decade, resulting in an increase in plastic-derived DOC that might have unaccounted consequences for marine microbes and for the ocean system.
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Catalá T.S., A.M. Martínez-Pérez, M. Nieto-Cid, M. Álvarez, J. Otero, M. Emelianov, I. Reche, J. Arístegui, X.A. Álvarez-Salgado
Progress in Oceanography, 165, 35-51. DOI: 10.1016/j.pocean.2018.05.002 (BibTeX: catala.etal.2018)
Resum: Veure
Chromophoric dissolved organic matter (CDOM) in the open Mediterranean Sea (MedSea) is barely documented, remaining the basin–wide patterns in intermediate and deep waters still enigmatic. Here, full–depth distributions of CDOM absorption coefficients and spectral slopes recorded during the HOTMIX 2014 cruise are presented and their respective environmental drivers resolved. General Additive Models (GAMs) in surface waters and Optimum MultiParameter (OMP) water mass analysis in deep waters were applied. In the surface, apparent oxygen utilisation (AOU), a proxy to cumulative net community respiration, explained most of the variability of dissolved organic carbon (DOC) and the absorption coefficient at 254 nm (a254), whereas the absorption coefficient at 325 nm (a325), and the spectral slopes were mostly explained by potential temperature, a proxy to stratification and solar radiation, indicating that both water column stability and photobleaching may drive the variability of the UV–A absorbing CDOM components. In deep waters, the effect of water mass mixing and basin–scale mineralization were discerned from local mineralization processes. Water mass mixing and basin– scale mineralization contributed more substantially to explain the variability of DOC, a254 and a325 (82–91%) than the variability of the spectral slopes (35–64%). Local mineralization processes indicate that DOC and CDOM play a more relevant role in the carbon cycle in the Eastern (EastMed) than in the Western (WestMed) Mediterranean: whereas DOC contributed to 66 ± 10% of the oxygen demand in the EastMed, it represented only 24 ± 4% in the WestMed. Independently of basins and layers, a254 revealed as an excellent proxy to the concentration of DOC in the MedSea. Also, the unexpected inverse relationship of a325 with AOU indicates that the consumption of the UV–A absorbing CDOM fraction prevails over their production.
Paraules clau: Dissolved organic carbon Chromophoric dissolved organic matter Water masses Biogeochemistry Mediterranean Sea
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Martínez-Pérez A.M., T.S. Catalá, M. Nieto-Cid, J. Otero, M. Álvarez, M. Emelianov, I. Reche, X.A. Álvarez-Salgado, J. Arístegui
Progress in Oceanography, 170, 93-106. DOI: 10.1016/j.pocean.2018.10.019 (BibTeX: martinezperez.etal.2018)
Resum: Veure
Fluorescent dissolved organic matter (FDOM) in the Mediterranean Sea was analysed by excitation–emission matrix (EEM) spectroscopy and parallel factor (PARAFAC) analysis during the cruise HOTMIX 2014. A 4–component model, including 3 humic–like and 1 protein–like compounds, was obtained. To decipher the environmental factors that dictate the distributions of these components, we run generalized additive models (GAMs) in the epipelagic layer and an optimum multiparametric (OMP) water masses analysis in the meso– and bathypelagic layers. In the epipelagic layer, apparent oxygen utilization (AOU) and temperature presented the most significant effects on the variability of the marine humic-like peak M fluorescence, suggesting that its distribution was controlled by the net community respiration of organic matter and photobleaching. On the contrary, the variability of the soil humic-like peak E and the protein–like peak T fluorescence was explained mainly by the prokaryotic heterotrophic abundance, which decreased eastwards. In the meso– and bathypelagic layers, water mass mixing and basin–scale mineralization processes explained>72% and 63% of the humic–like and protein–like fluorescence variability, respectively. When analysing the two basins separately, the OMP model offered a better explanation of the distribution of fluorescence in the eastern Mediterranean Sea, as expected from the reduced biological activity in this ultra–oligotrophic basin. Furthermore, while western Mediterranean deep waters display the usual trend in the global ocean (increase of humic–like fluorescence and decrease of protein–like fluorescence with higher AOU values), the eastern Mediterranean deep waters presented an opposite trend. Different initial fluorescence intensities of the water masses that mix in the eastern basin, with Adriatic and Aegean origins, seem to be behind this contrasting pattern. The analysis of the transect–scale mineralization processes corroborate this hypothesis, suggesting a production of humic–like and a consumption of protein–like fluorescence in parallel with water mass ageing. Remarkably, the transect–scale variability of the chromophoric dissolved organic matter (CDOM) absorbing at the excitation wavelength of the humic–like peak M indicates an unexpected loss with increasing AOU, which suggests that the consumption of the non–- fluorescent fraction of CDOM absorbing at that wavelength exceeded the production of the fluorescent fraction observed here.
Paraules clau: Dissolved organic matter Fluorescence spectroscopy PARAFAC Water mass analysis Mediterranean Sea
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Pagès-Ecsolà M., B. Hereu, J. Garrabou, I. Montero-Serra, A. Gori, D. Gómez-Gras, B. Figuerola, C. Linares
Scientific Reports, 8, 17455, 1-9. DOI: 10.1038/s41598-018-36094-9 (BibTeX: pagesecsola.etal.2018)
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Guerrero E., J.-M. Gili, F. Maynou, A. Sabatés
Journal of Plankton Research, 40, 2, 178-196. DOI: 10.1093/plankt/fby001 (BibTeX: guerrero.etal.2018c)
Resum: Veure
Knowing the variations of planktonic cnidarians under climate change conditions is of importance due to the key role of carnivorous gelatinous zooplankton in the pelagic ecosystem. We investigated the abundance, spatial distribution, species richness and community structure of planktonic cnidarians in a temperate area, the NW Mediterranean, during the extremely warm summer of 2003 and the average summer of 2004. The surveys covered a broad and heterogeneous area. During the warm summer, the cnidarian community was half as abundant as during 2004, whereas its diversity was higher. The mesoscale spatial distribution of several species varied between the years. The structure of the community had a coastal-offshore ordination in the typical summer, but a north–south one in the warm summer when the temperature gradient prevailed instead of the bathymetry. Only hydromedusae were more abundant during the warm summer. The dominant siphonophore, Muggiaea atlantica, exhibited one of the greatest abundance decreases in 2003. Our results emphasize that exceptionally warm summer conditions could reduce gelatinous zooplankton abundance and change their latitudinal distribution and community composition. We stress the importance of mesoscale plankton surveys, including detailed taxonomic identification, as a critical tool for better understanding marine ecosystem responses to climatic variability.
Paraules clau: Species richness, Extreme climatic events, Summer 2003 heat wave, NW Mediterranean, Shannon diversity index
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Ali Raheem Tuaimah Al-Nassar .,
PhD thesis. Director/es: M. Alarcón, J.L. Pelegrí. (BibTeX: raheemtuaimahalnassar.2018)
Resum: Veure
Precipitation is one of the most important, and also difficult to predict, elements of climate. This difficulty is associated with the transport of moisture through weather fronts that change their pathway, shape and intensity at different spatial and temporal scales. Despite this difficulty, a proper rainfall prediction is necessary both to quantify the resources and infrastructures necessary to bring water to farm fields and cities and to anticipate the occurrence of extreme precipitation episodes that may cause human death and huge economic losses. The main objective of this dissertation is to investigate the influence of weather systems on the patterns and amount of precipitation over Iraq, from its variability at different temporal scales (daily to inter-decadal) to the contribution of severe precipitation events to total rainfall and the mechanisms underlying these extreme episodes. With this objective, we use monthly (1938-2016) and daily (2005-2016) precipitation records from a meteorological station in the city of Baghdad, ran by the Iraqi Meteorological and Seismology Organization. Additionally, we use the temperature, humidity, geopotential height, horizontal and vertical velocity, horizontal divergence, relative vorticity and potential vorticity fields from the ERA-Interim global atmospheric reanalysis, available four times a day on a 0.75º × 0.75º latitude-longitude grid from the European Centre for Medium-Range Weather Forecasts (ECMWF). These data, downloaded for a domain extending from 0°E to 60°E and from 10°N to 60°N, are then used to calculate the equivalent potential temperature, precipitable water, moisture flux, moisture flux convergence, Q-vector divergence, relative vorticity and potential vorticity advection, as well as several instability indices (K, CAPE, SWEAT and LI). In Chapter 2 we focus on the analysis of the monthly rainfall data for the 1938-2016 period. The mean annual precipitation is 135.8 ± 61.9 mm/yr and the mean monthly precipitation is 11.3 ± 18.7 mm. Despite the linear trend for the entire period is small, there are decades (1950s and 1960s) of relatively high mean-annual precipitation and other ones (1990s and 2000s) with substantially lower values. The monthly rainfall time series also shows the existence of substantial inter-annual variations, with annual precipitation values ranging between 29.3 and 307.7 mm (2012 and 1974, respectively). The seasonal cycle changes substantially between arid and wet years, with December-February receiving most during the arid years, and November-April collecting most precipitation during the wet years. The inter-annual changes in precipitation show no correlation with a global index for El Niño-Southern Oscillation. In Chapter 3 we analyse a 12-year time series of daily data (2005-2016) from the Baghdad meteorological station. We identify the contribution of cut-off lows to precipitation: 38 events contributed to 43.4% of the total precipitation over Baghdad. Cut-off lows occur all year long but those happening between October and December account for one-third of the total annual precipitation. In Chapter 4 we have considered the dynamics behind the 18-20 November 2013 extreme rainfall episode, the largest one since 1980. The middle and upper atmospheric conditions resulted from the development of an omega block into a Rex block. The eastern part of the cyclonic structure of the Rex block was experiencing horizontal divergence and the associated upward motions reached all the way from 1000 to 250 hPa. Simultaneously, the lower atmosphere (1000 to 700 hPa) exhibited intense southerly cool winds that brought large amounts of moisture into central Iraq. Finally, in Chapter 5 we again combine the daily Baghdad rainfall data with the ERA-Interim analysis to explore the weather patterns associated with the 20 extreme precipitation events for the 2005-2016 period. These events brought 805.2 mm (51.3%) of the total precipitation to the Baghdad station.
Paraules clau: Dinámica atmosférica, Climatología aplicada, Meteorología
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Vila M., V. Giussani, L. Viure, E. Alechaga, E. Moyano, S. Hernández-Llamas, E. Berdalet
, Ed. L.A.O. Proença and G.M. Hallegraeff. ISBN: 978-87-990827-6-6 (BibTeX: vila.etal.2018)
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de Juan S., M.D. Subida, S. Gelcich, M. Fernandez
Ecological Indicators, 88, 361-371. DOI: 10.1016/j.ecolind.2018.01.054 (BibTeX: dejuan.etal.2018a)
Resum: Veure
The assessment of the status of marine ecosystems is still a major challenge, because in general we lack well-established ecosystem-based monitoring programs. The coast of central Chile is subjected to moderate but historic fishing pressure by small-scale fisheries. In spite of the increasing evidences of the impact of fishing beyond target species, there is a lack of systematic ecosystem-based assessments. We focused on this problem with the goal of identifying community components, based on a Biological Traits Analysis, that respond to fishing activities to ultimately define ecosystem health. We sampled a set of study sites subjected to benthic invertebrate gathering, and more recently to kelp harvesting. Sites included paired fishery restricted and open access areas where mobile invertebrates and sessile benthos were surveyed. In addition, kelp density and size structure were assessed in two sites subjected to kelp harvesting (also pairing restricted and open access areas). Target species exhibited higher densities in fishery-restricted areas. Fisheries restricted-areas also showed overall higher richness and redundancy of biological traits. Otherwise, we observed high variability in the structure of sessile benthos linked to small-scale heterogeneity of the seabed. The areas subjected to kelp harvesting exhibited variability in mobile invertebrates’ composition between fishing access regimes, whereas no effects could be detected by only considering target species. Current monitoring efforts seem to be well-suited to address target species but fail to inform on ecosystem health in an area with increasing signs of community-wide effects from fishing. Therefore, we recommend future monitoring schemes targeting community components, beyond commercial species’ densities, at different scales
Paraules clau: Benthic communities; Biological Traits Analysis; Ecosystem indicators; Fishing impacts; Kelp forests
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Fernández‐Montero A., M.J. Caballero, S. Torrecillas, V.M.Tuset, A. Lombarte, R. Ruiz Ginés, M.l Izquierdo, L. Robaina, D. Montero
Aquaculture Research, 49, 2, 908-918. DOI: 10.1111/are.13537 (BibTeX: fernandezmontero.etal.2018a)
Resum: Veure
In order to successfully diversify Mediterranean aquaculture, it is necessary to determine optimum culture conditions of potential candidate species such as greater amberjack (Seriola dumerili). Among culture conditions, rearing temperature is a key factor for achieving optimum growth and maintaining fish welfare. However, little is known about the optimum culture conditions of greater amberjack (Seriola dumerili). Thus, the aim of this study was to determine the effect of three different rearing temperatures (17, 22 and 26°C) during 120 days on growth performance, body morphometry, biochemical composition, gut transit and liver morphology of greater amberjack (Seriola dumerili) juveniles. After 120 days of rearing, fish raised at 26°C showed higher (p < .05) body weight and specific growth rate than fish held at lower temperatures, as well as improved feed utilization, protein efficiency and nutrient retention percentages. Fish stomach emptying was faster (p < .05) in fish raised at 26°C than in fish held at 22°C and 17°C. Similar results were obtained for gut transit time, being gut emptying faster (p < .05) in fish reared at 26°C than in fish cultured at lower temperatures. Rearing temperature also induced changes in fish morphology which resulted in a higher (p < .05) caudal propulsion efficiency index for fish reared at 26°C. Based on these results, we conclude that greater amberjack fingerlings perform better at 26°C than at 22°C or 17°C.
Paraules clau: Feed efficiency, Gastric evacuation, Greater amberjack, Gut transit, Morphometric analyses, Rearing temperature, Seriola dumerili
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Sew G., A. Calbet, G. Drillet, P. A. Todd
Marine Environmental Research, 140, 251-264. DOI: 10.1016/j.marenvres.2018.06.016 (BibTeX: sew.etal.2018)
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Martínez R.A., A. Calbet, E. Saiz
Aquatic Sciences, 80, 2, 1-11. DOI: 10.1007/s00027-017-0558-8 (BibTeX: martinez.etal.2018c)
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Pierdomenico M ., Russo T, Ambroso S, Gori A, Martorelli E, D\'Andrea L, Gili JM, Chiocci FL
Progress in Oceanography, 169, 214-226. DOI: 10.1016/j.pocean.2018.02.019 (BibTeX: m.etal.2018)
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Solé M., J.C. Sanchez-Hernandez
Ecological Indicators, 85, 432-439. DOI: 10.1016/j.ecolind.2017.10.046 (BibTeX: sole.sanchezhernandez.2018a)
Resum: Veure
Carboxylesterases (CEs) are α,β-hydrolase fold proteins that catalyse the hydrolysis of a wide range of endogenous and exogenous compounds. In mammals, these enzymes are involved in the detoxification of certain pesticides and drugs. However, this toxicological role of CEs has received little attention in marine organisms such as the mussel Mytilus galloprovincialis. Therefore, the purpose of this study was to examine whether mussel CE activity is sensitive to inhibition by environmental chemicals of current concern (human pharmaceuticals and personal care products or PPCPs; i.e fluoxetine, loperamide, simvastatin, fenofibrate, nonylphenol and triclosan), so this chemical interaction may be considered as a detoxification mechanism comparable to that of organophosphorus pesticides. First, we examined the basal levels of CE activity in multiple tissues of M. galloprovincialis, using a wide range of colorimetric substrates, i.e., p-nitrophenyl acetate (pNPA), p-nitrophenyl butyrate (pNPB), 1-naphthyl acetate (1-NA), 1-naphthyl butyrate (1-NB) and 2-naphtyl acetate (2-NA). Second, we tested for a substrate-dependence of detecting CE inhibition using the model organophosphorus dichlorvos. Finally, some PPCPs were tested for in vitro CE inhibition using multiple substrates. Results showed that long-chain esters (pNPB and 1-NB) provided the highest CE-mediated hydrolysis rates compared with pNPA or 1-NA. Moreover, the digestive gland and gills displayed the highest CE activities compared with haemolymph. As expected, the esterase enzyme was very sensitive to dichlorvos (IC50 s in the nM range), but dose-inhibition relationships were markedly dependent on the type of substrate used for enzyme assay. The in vitro inhibition kinetics identified triclosan as a potential CE inhibitor (IC50 = 7.07–27.2 μM for digestive gland, IC50 = 10.8–104 μM for gill CE activity), although other PPCPs such as simvastatin, fenofibrate and nonylphenol also decreased the enzyme activity to a lesser extent. In-gel esterase staining after non-denaturing polyacrylamide gel electrophoresis confirmed the inhibitory effect of triclosan upon CE activity, which was more pronounced with the substrate 1-NB. These findings suggest that CE inhibition may be a suitable biomarker of PPCP exposure to be incorporated into the battery of sub-individual indicators of PPCP exposure and toxicity. However, the selection of appropriate substrates is a key issue. Our results indicated that pNPB and 1-NB are the most suitable reporters for detecting inhibition of CE by both organophosphorus and PPCPs in mussels.
Paraules clau: Carboxylesterases, mussel, triclosan, native PAGE, PPCPs
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Olmedo E., V. González-Gambau, A. Turiel, J. Martínez, C. Gabarró, J. Ballabrera-Poy, M. Portabella, M. Arias, R. Sabia
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Valencia, Spain, 22-27 July, 2018., . (BibTeX: olmedo.etal.2018b)
Resum: Veure
After more than eight years of Soil Moisture and Ocean Salinity (SMOS) aquisitions, an empirical characterization of the biases and the computation of an effective brightness temperature uncertainty is possible. In this work we show that both parameters strongly depend on the geographical location of the acquisition. Metrics based on the differences between expected and theoretical values of the bias and uncertainty are developed and used for a quantitative assessment of the locations where SMOS errors are currently being worse characterized. This characterization can be used for the definition of an empirical bias correction and a more accurate cost function which are expected to provide a better SMOS SSS product.
Paraules clau: SMOS, Sea Surface Salinity, Brightness Temperature biases, Brightness Temperature uncertainty
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Kingsford M.J., S. Becken, C. Bordehore, V.L. Fuentes, K.A. Pitt, A.A. Yangihara
Coastal Management, 46, 1, 1-18. DOI: 10.1080/08920753.2018.1405326 (BibTeX: kingsford.etal.2018)
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Hoareau N., M. Portabella, W. Lin, J. Ballabrera, A. Turiel
Proc. of the International Conference on Marine Data and Information Systems (IMDIS), Barcelona, Spain, 5-7 November, 2018., . (BibTeX: hoareau.etal.2018b)
Resum: Veure
The monitoring of the global distribution of sea surface salinity (SSS) is vital to understand the ocean’s role in the Earth’s climate. Until the advent of the spaceborne L-band radiometers, SSS observations were mainly acquired by in-situ sensors (moored buoys, drifters, and thermosalinographs). As a result, knowledge of the spatial and temporal variability of salinity has been scarce due to the lack of a comprehensive set of salinity observations. While in-situ data (e.g., Argo floats) were being used in a growing number of studies, numerical models were also widely used as a complementary source of such information. The spatiotemporal resolution achieved by satellite salinity measurements has no equivalent among the other existing salinity observations systems. Since the launch of the Soil Moisture and Ocean Salinity (SMOS) mission (2009) and then the Aquarius mission (2001), more than seven years of satellite-derived SSS data, with a spatial and temporal resolution adequate for climate and ocean general circulation studies, have become available. The L-band radiometers onboard SMOS and Aquarius have proven to be challenging and various spatial and temporal averaging and data fusion techniques have been implemented to better recover structured and meaningful geophysical information from remote sensing SSS retrievals. A comprehensive validation is therefore essential to characterize the information provided by the different salinity products.
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Hoareau N., M. Portabella, W. Lin, J. Ballabrera-Poy, A. Turiel
IEEE Transactions on Geoscience and Remote Sensing, 56, 9, 5160-5168. DOI: doi.org/10.1109/TGRS.2018.2810442 (BibTeX: hoareau.etal.2018c)
Resum: Veure
The triple collocation (TC) technique allows the simultaneous calibration of three independent, collocated data sources, while providing an estimate of their accuracy. In this paper, the TC is adapted to validate different salinity data products along the tropical band. The representativeness error (the true variance resolved by the relatively high-resolution systems but not by the relatively low-resolution system) is accounted for in the validation process. A method based on the intercalibration capabilities of TC is used to estimate the representativeness error for each triplet, which is found to impact between 15% and 50% the error estimation of the different products. The method also sorts the different products in terms of their resolving spatiotemporal scales. Six salinity products (sorted from smaller to larger scales) used were: the in situ data from the Global Tropical Moored Buoy Array (TAO), the GLORYS2V3 ocean reanalysis output provided by Copernicus, the satellite-derived Aquarius Level 3 version 4 (AV4) and Soil Moisture and Ocean Salinity (SMOS) objectively analyzed (SOA) maps, and the climatology maps provided by the World Ocean Atlas (WOA). This calibration study is limited to the year 2013, a year when all the products were available. This validation approach aims to assess the quality of the different salinity products at the satellite-resolved spatiotemporal scales. The results show that, at the AV4 resolved scales, the Aquarius product has an error of 0.17, and outperforms TAO, GLORYS2V3, and the SOA maps. However, at the SOA resolved scales (which are coarser than those of the Aquarius product because of the large OA correlation radii used), the SMOS product has an error of 0.20, slightly lower than that of GLORYS2V3, Aquarius, and TAO. The WOA products show the highest errors. Higher order calibration may lead to a more accurate assessment of the quality of the climatological products.
Paraules clau: Error analysis; Remote sensing; Sea measurements
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Kudela R.M., R. Raine, G. Pitcher, P. Gentien, E. Berdalet, H. Enevoldsen, E. Urban.
In: Global Ecology and Oceanography of Harmful Algal Blooms, Ecological Studies - Analysis and Synthesis Series.. Vol. 232. Ed. Glibert, P.M., Berdalet, E., Burfort, M., Pitcher, G.. Springer International Publishing AG, Switzerland. Chap. 3. 27-49. DOI: 10.1007/978-3-319-70069-4_3 ISBN: 978-3-319-70069-4 (BibTeX: kudela.etal.2018a)
Resum: Veure
The Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB) Programme was established in 2001 under the sponsorship of the Intergovernmental Oceanographic Commission (IOC) of UNESCO and the Scientific Committee on Oceanic Research (SCOR). GEOHAB was the first international research programme focusing exclusively on harmful marine algae. The GEOHAB mission was to foster international cooperation to advance understanding of HAB dynamics and to improve our ability to predict these events, with the final aim to inform and facilitate management and mitigation of the associated negative impacts. GEOHAB focused on the physiological, behavioural, and genetic characteristics of harmful microalgal species and the interactions between physical and other environmental conditions that promote the success of one group of species over another. A hallmark of GEOHAB was that it championed a comparative approach, across organisms, regions, and ecosystems. GEOHAB advanced our understanding of the mechanisms underlying population dynamics of HABs within an ecological and oceanographic context and also from the ecosystem perspective at the regional scale. GEOHAB encouraged combined experimental, observational, and modelling tools using existing and innovative technologies in a multidisciplinary approach. This deliberately integrative and multidisciplinary framework was consistent with the multiple scales and oceanographic complexity of marine HAB phenomena. One of the legacies of GEOHAB was that it established the basis for continued international efforts to better understand and predict the complex global phenomena of harmful algal blooms, leading in 2016 to the follow-on effort, GlobalHAB, which will continue and extend GEOHAB’s mission.
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del Campo J., M. Kolisko, V. Boscaro, L. Santoferrara, R. Massana, L. Guillou, A. Simpson, C. Berney, C. de Vargas, M. Brown, P. Keeling, L. W. Parfrey
Plos Biology, 16, 9, 1-14. DOI: 10.1371/journal.pbio.2005849 (BibTeX: delcampo.etal.2018)
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Guiomar Rotllant ., T.V. Nguyen, D. Hurwood, V. Sbragaglia, T. Ventura, J.B. Company, S. Joly, A. Elizur, P.B. Mather
Hydrobiologia, 825, 1, 137-158. DOI: 10.1007/s10750-018-3521-3 (BibTeX: rotllant.etal.2018e)
Resum: Veure
The Norway lobster Nephrops norvegicus is the most important commercial crustacean species in Europe. Recent decline in wild captures and a reduction in total abundance and size at first maturation indicate that the species is overexploited. Increasing knowledge of its reproduction, specifically at the molecular level will be mandatory to improving fisheries management. The current study investigated differences between immature and mature N. norvegicus females using Next Generation Sequencing technology applied to multiple tissues. Ovarian maturation-related differential expression patterns were observed for 4362 transcripts in ovary, hepatopancreas, eyestalk, brain, and thoracic ganglia in N. norvegicus. Transcripts detected in the study include vitellogenin, crustacean hyperglycaemic hormone, retinoid X receptor, heat shock protein 90 and proteins encoding lipid and carbohydrate metabolizing enzymes. From the study, data were collected that can prove valuable in developing more comprehensive knowledge of the reproductive system in this lobster species during the ovarian maturation process. Additional studies will be required, however, to identify potential novel genes and to develop a molecular toolkit for crustacean species that can be applied to improving sustainable future production.
Paraules clau: Oocyte; Fecundity; Size at maturity; Reproduction; Fisheries; Next generation sequencing
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Solé M., M. Bonsignore, G. Rivera-Ingraham, R. Freitas
Marine Pollution Bulletin, 136, 61-67. DOI: 10.1016/j.marpolbul.2018.08.062 (BibTeX: sole.etal.2018d)
Resum: Veure
Acetylcholinesterase (AChE) is a reliable biomarker of pesticide exposure although in clams this activity is often very low or undetectable. Carboxylesterases (CEs) exhort several physiological roles, but also respond to pesticides. Searching for an AChE alternative, baseline CE activities were characterised in Ruditapes decussatus gills and digestive glands using five substrates suggestive of different isozymes. The long chain p-nitrophenyl butyrate and 1-naphthyl butyrate were the most sensitive. In the digestive gland, their kinetic parameters (Vmax and Km) and in vitro sensitivity to the organophosphorus metabolite chlorpyrifos oxon (CPX) were calculated. IC50 values, in the pM–nM range, suggest a high protection efficiency of CE-related enzymes towards CPX neurotoxicity. Other targeted enzymes were: activities of glutathione reductase, glutathione peroxidase, catalase, glutathione S-transferases (GSTs) and lactate dehydrogenase in gills and digestive glands. The high GSTs activity and CE/AChE ratio suggests that R. decussatus has a great capacity for enduring pesticide exposure
Paraules clau: Carboxylesterases; Organophosphorus pesticides; Chlorpyrifos oxon; Antioxidant enzymes; Ruditapes decussatus
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Otero-Ferrer J.L., P. Cermeño, A. Bode, B. Fernández-Castro, J.M. Gasol, X.A. G. Morán, E. Marañon, V. Moreira-Coello, M.M. Varela, M. Villamaña, B. Mouriño-Carballido
Biogeosciences, 15, 6199-6220. DOI: 10.5194/bg-15-6199-2018 (BibTeX: oteroferrer.etal.2018a)
Resum: Veure
The effect of inorganic nutrients on planktonic assemblages has traditionally relied on concentrations rather than estimates of nutrient supply. We combined a novel dataset of hydrographic properties, turbulent mixing, nutrient concentration, and picoplankton community composition with the aims of (i) quantifying the role of temperature, light, and nitrate fluxes as factors controlling the distribution of autotrophic and heterotrophic picoplankton subgroups, as determined by flow cytometry, and (ii) describing the ecological niches of the various components of the picoplankton community. Data were collected at 97 stations in the Atlantic Ocean, including tropical and subtropical open-ocean waters, the northwestern Mediterranean Sea, and the Galician coastal upwelling system of the northwest Iberian Peninsula. A generalized additive model (GAM) approach was used to predict depth-integrated biomass of each picoplankton subgroup based on three niche predictors: sea surface temperature, averaged daily surface irradiance, and the transport of nitrate into the euphotic zone, through both diffusion and advection. In addition, niche overlap among different picoplankton subgroups was computed using nonparametric kernel density functions. Temperature and nitrate supply were more relevant than light in predicting the biomass of most picoplankton subgroups, except for Prochlorococcus and low-nucleic-acid (LNA) prokaryotes, for which irradiance also played a significant role. Nitrate supply was the only factor that allowed the distinction among the ecological niches of all autotrophic and heterotrophic picoplankton subgroups. Prochlorococcus and LNA prokaryotes were more abundant in warmer waters ( > 20°C) where the nitrate fluxes were low, whereas Synechococcus and high-nucleic-acid (HNA) prokaryotes prevailed mainly in cooler environments characterized by intermediate or high levels of nitrate supply. Finally, the niche of picoeukaryotes was defined by low temperatures and high nitrate supply. These results support the key role of nitrate supply, as it not only promotes the growth of large phytoplankton, but it also controls the structure of marine picoplankton communities.
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Viladrich N., A. Gori, J.M. Gili
Marine Biodiversity, 48, 951-952. (BibTeX: viladrich.etal.2018)
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Barría C., J. Navarro, M. Coll
Deep-Sea Research. Part I: Oceanographic Research Papers, 142, 34-43. DOI: 10.1016/j.dsr.2018.09.010 (BibTeX: barria.etal.2018n)
Resum: Veure
The study of the feeding ecology of marine predators is crucial to understanding their ecological roles and advancing our knowledge of marine ecosystem functioning, especially in highly human-impacted areas. Here, we examined the trophic ecology of three abundant demersal sharks, the velvet belly lantern shark Etmopterus spinax, the blackmouth catshark Galeus melastomus and the small-spotted catshark Scyliorhinus canicula, and the rare kitefin shark Dalatias licha of the western Mediterranean Sea. Data were obtained from two deep-water areas with different degrees of human impact: a fishery restricted area (FRA) in the Gulf of Lions and a highly human-impacted area in the Catalan Sea (non-FRA). We combined analyses of individual stomach contents and stable isotope values from different individuals of each shark species. Our results revealed that D. licha is a predator located higher up on the food web, while G. melastomus, E. spinax and S. canicula are located in lower trophic positions. These results confirm that shark species play important and, most likely, complementary roles as predators in the western Mediterranean Sea. Results also revealed that despite some differences in the diet of the shark species, as revealed by the stomach contents, in the long term (isotopic results) the four species showed similar diet habits and similar trophic relationships in both FRA and non-FRA. This may be due to the fact that despite the fishing regulations in the FRA area, the population of the prey species probably do not vary between the two areas. Overall, this study provides new insights into the trophic ecology of these sharks and contributes to an understanding of their ecological roles within the community.
Paraules clau: Ecological role; Feeding ecology; Mediterranean Sea; Sharks; Trophic relationships
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Guerrero E., K. Kienberger, A. Villaescusa, J.M. Gili, G. Navarro, L. Prieto
Marine Biodiversity, 1-7. DOI: 10.1007/s12526-018-0926-1 (BibTeX: guerrero.etal.2018f)
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Glibert P.M., E. Berdalet, M. A. Burford, G.C. Pitcher, M. Zhou
Ed. P.M. Glibert, E. Berdalet, M. Burfort, G. Pitcher, M. Zhou (Eds.). Springer International Publishing AG. 232, In: Ecological Studies - Analysis and Synthesis Series. 461. ISBN: 978-3-319-70068-7 (BibTeX: glibert.etal.2018d)
Resum: Veure
Harmful algal blooms (HABs) - blooms that cause fish kills, contaminate seafood with toxins, or cause human or ecological health impacts and harm to local economies - are occurring more often, in more places and lasting longer than in past decades. This expansion is primarily the result of human activities, through increased nutrient inputs and various aspects of climate change. The Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB) programme promoted international collaboration to understand HAB population dynamics in various oceanographic regimes and to improve the prediction of HABs. This volume introduces readers to the overarching framework of the GEOHAB programme, factors contributing to the global expansion of harmful algal blooms, the complexities of HABs in different habitats, and the forward-looking issues to be tackled by the next generation of GEOHAB, GlobalHAB. The programme brought together an international team of contributing scientists and ecosystem managers, and its outcomes will greatly benefit the international research community.
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Berdalet E., R. Kudela, N. S. Banas, E. Bresnan, M. Burford, K. Davidson, C. J. Gobler, B. Karlson, P.-T. Lim, L. Mackenzie, M. Montresor, V. L. Trainer, G. Usup, K. Yin, H. Enevoldsen, E. Urban.
In: Global Ecology and Oceanography of Harmful Algal Blooms., Ecological Studies - Analysis and Synthesis Series.. Vol. 232. Ed. Glibert, P.M., Berdalet, E., Burfort, M., Pitcher, G., M. Zhou. Springer International Publishing AG, Switzerland. Chap. 22. 425-447. DOI: 10.1007/978-3-319-70069-4_22 ISBN: 978-3-319-70069-4 (BibTeX: berdalet.etal.2018a)
Resum: Veure
GlobalHAB, “Global Harmful Algal Blooms,” is a new scientific programme on harmful algal blooms (HABs) cosponsored by the Intergovernmental Oceanographic Commission (IOC) of UNESCO and the Scientific Committee on Oceanic Research (SCOR) that will operate for 10 years from 2016 to 2025. GlobalHAB builds on the solid foundation established by the former programme GEOHAB and will continue to promote coordinated international scientific activities, which is fundamental to keep progressing on the comprehension of the global complexity of HABs and that will contribute to the management and mitigation of their impacts worldwide. The GlobalHAB Scientific and Implementation Plan is briefly presented in this chapter.
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Cardellach E., J. Wickert, R. Baggen, J. Benito, A. Camps, N. Catarino, B. Chapron, A. Dielacher, F. Fabra, G. Flato, H. Fragner, C. Gabarró, C. Gommenginger, C. Haas, S. Healy, M. Hernández-Pajares, P. Hoeg, A. Jäggi, J. Kainulainen, S.A. Khan, N.M.K. Lemke, W. Li, S.V. Nghiem, N. Pierdicca, M. Portabella, K. Rautiainen, A. Rius, I. Sasgen, M. Semmling, C.K. Shum, F. Soulat, A.K. Steiner, S. Tailhades, M. Thomas, R. Vilaseca, C. Zuffada
IEEE Access, 6, 13980 - 14018. DOI: 10.1109/ACCESS.2018.2814072 (BibTeX: cardellach.etal.2018)
Resum: Veure
The global navigation satellite system (GNSS) Transpolar Earth Reflectometry exploriNg system (G-TERN) was proposed in response to ESA\'s Earth Explorer 9 revised call by a team of 33 multi-disciplinary scientists. The primary objective of the mission is to quantify at high spatio-temporal resolution crucial characteristics, processes and interactions between sea ice, and other Earth system components in order to advance the understanding and prediction of climate change and its impacts on the environment and society. The objective is articulated through three key questions. 1) In a rapidly changing Arctic regime and under the resilient Antarctic sea ice trend, how will highly dynamic forcings and couplings between the various components of the ocean, atmosphere, and cryosphere modify or influence the processes governing the characteristics of the sea ice cover (ice production, growth, deformation, and melt)? 2) What are the impacts of extreme events and feedback mechanisms on sea ice evolution? 3) What are the effects of the cryosphere behaviors, either rapidly changing or resiliently stable, on the global oceanic and atmospheric circulation and mid-latitude extreme events? To contribute answering these questions, G-TERN will measure key parameters of the sea ice, the oceans, and the atmosphere with frequent and dense coverage over polar areas, becoming a ``dynamic mapper\'\' of the ice conditions, the ice production, and the loss in multiple time and space scales, and surrounding environment. Over polar areas, the G-TERN will measure sea ice surface elevation (<10 cm precision), roughness, and polarimetry aspects at 30-km resolution and 3-days full coverage. G-TERN will implement the interferometric GNSS reflectometry concept, from a single satellite in near-polar orbit with capability for 12 simultaneous observations. Unlike currently orbiting GNSS reflectometry missions, the G-TERN uses the full GNSS available bandwidth to improve its ranging measurements. The lifetime would be 2025-2030 or optimally 2025-2035,covering key stages of the transition toward a nearly ice-free Arctic Ocean in summer. This paper describes the mission objectives, it reviews its measurement techniques, summarizes the suggested implementation, and finally, it estimates the expected performance.
Paraules clau: Polar science, GNSS, reflectometry, GNSS-R, sea ice, altimetry, polarimetry, radio-occultation, Low Earth Orbiter.
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Nguyen T.V., H. Jung, G. Rotllant, D.Hurwood, P. Mather, T. Ventura
Hydrobiologia, 825, 1, 5-27. DOI: 10.1007/s10750-018-3682-0 (BibTeX: nguyen.etal.2018b)
Resum: Veure
Next-generation sequencing (NGS) has dramatically changed the way biological research is being conducted in the post-genomic era, and they have only been utilized widely over the recent decade for studies of non-model decapod crustacean species, predominantly by sequencing the transcriptome of various tissues across different life stages. Next-generation sequencing can now provide a rapid, cost-effective solution for discovery of genetic markers crucial in many applications that would previously have otherwise taken years to develop. Sequencing of the entire transcriptome (referred to as RNA sequencing; RNA-seq) is one of the most popular NGS tools. RNA-seq studies of non-model species in crustacean taxa, however, have faced some problems, including a lack of “good” experimental study design, a relative paucity of gene annotations, combined with limited knowledge of genomic technologies and analyses. The aim of the current review is to assist crustacean biologists to develop a better appreciation for the applications and scope of RNA-seq analysis, understand the basic requirements for optimal RNA-seq studies and provide an overview of each step, from RNA-seq experimental design to bioinformatics approaches to data analysis. Insights that have resulted from RNA-seq studies across a wide range of non-model decapod species are also summarized.
Paraules clau: RNA-sequencing; Next-generation sequencing; Differential gene expression; Shrimp; Prawn; Crab; Lobster; Crayfish; In silico
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Glibert P.M., E. Berdalet, M. Burfort, G. Pitcher, M. Zhou
In: Global Ecology and Oceanography of Harmful Algal Blooms, Ecological Studies - Analysis and Synthesis Series.. Vol. 232. Ed. Glibert, P.M., Berdalet, E., Burfort, M., Pitcher, G., M. Zhou. Springer International Publishing AG, Switzerland. Chap. 2. 9-25. DOI: 10.1007/978-3-319-70069-4_2 ISBN: 978-3-319-70069-4 (BibTeX: glibert.etal.2018e)
Resum: Veure
The complexity of the harmful algal bloom (HAB) problem, its causative factors, and the impacts HABs have on the environment are becoming well characterized. The benefits of collaborative, cooperative, and comparative studies on HABs are important in advancing the understanding of this phenomenon and to provide scientific guidance to managers. This chapter introduces several aspects of this complex phenomenon, by addressing the following questions: what are HABs, how are they harmful, where do they occur, why are they expanding, and why the need for an improved understanding of their ecology and oceanography? In so doing, this chapter lays the foundation for the following chapters in this volume that probe these questions and the related advancements in research in more detail.
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Calbet A., E. Saiz
Journal of Plankton Research, 40, 2, 109-117. DOI: 10.1093/plankt/fbx070 (BibTeX: calbet.saiz.2018)
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Lombarte A., M. Miletić, M. Kovačić, J.L. Otero‐Ferrer, V.M. Tuset
Journal of Fish Biology, 92, 6, 1768-1787. DOI: 10.1111/jfb.13615 (BibTeX: lombarte.etal.2018a)
Resum: Veure
In this study, we describe and analyse the morphology of the sagitta, the largest otolith, of 25 species of Gobiidae inhabiting the Adriatic and north‐western Mediterranean seas. Our goal was to test the usefulness and efficiency of sagittal otoliths for species identification. Our analysis of otolith contours was based on mathematical descriptors called wavelets, which are related to multi‐scale decompositions of contours. Two methods of classification were used: an iterative system based on 10 wavelets that searches the Anàlisi de Formes d\'Otòlits (AFORO) database and a discriminant method based only on the fifth wavelet. With the exception of paedomorphic species, the results showed that otolith anatomy and morphometry can be used as diagnostic characters distinguishing the three Mediterranean phylogenetic goby lineages (Pomatoschistus or sand‐goby lineage, Aphia lineage and Gobius lineage). The main anatomical differences were related to overall shape (square to rhomboid), the development and shape of the postero‐dorsal and antero‐ventral lobes and the degree of convexity of dorsal and ventral margins. Iterative classifications and discriminant analysis of otolith contour provided very similar results. In both cases, more than 70% of specimens were correctly classified to species and more than 80% to genus. Iterations in the larger AFORO database (including 216 families of teleosts) attained a 100% correct classification at the family level
Paraules clau: Contour; Gobiids; Mediterranean Sea; morphology; Otolith shape; Phylogeny
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Galindo‐Zaldivar J., G. Ercilla, F. Estrada, M. Catalán, E. d\'Acremont, O. Azzouz, D. Casas, M. Chourak, J.T. Vazquez, A. Chalouan, C. Sanz de Galdeano, M. Benmakhlouf, C. Gorini, B. Alonso, D. Palomino, J.A. Rengel, A.J. Gil
Tectonics, 37, 8, 2513-2530. DOI: 10.1029/2017TC004941 (BibTeX: galindozaldivar.etal.2018c)
Resum: Veure
The Eurasian‐African NW‐SE oblique plate convergence produces shortening and orthogonal extension in the Alboran Sea Basin (westernmost Mediterranean), located between the Betic and Rif Cordilleras. A NNE‐SSW broadband of deformation and seismicity affects the Alboran central part. After the 1993–1994 and 2004 seismic series, an earthquake sequence struck mainly its southern sector in 2016–2017 (main event Mw = 6.3, 25 January 2016). The near‐surface deformation is investigated using seismic profiles, multibeam bathymetry, gravity and seismicity data. Epicenters can be grouped into two main alignments. The northern WSW‐ENE alignment has reverse earthquake focal mechanisms, and in its epicentral region recent mass transport deposits occur. The southern alignment consists of a NNE‐SSW vertical sinistral deformation zone, with early epicenters of higher‐magnitude earthquakes located along a narrow band 5 to 10‐km offset westward of the Al Idrisi Fault. Here near‐surface deformation includes active NW‐SE vertical and normal faults, unmapped until now. Later, epicenters spread eastward, reaching the Al Idrisi Fault, characterized by discontinuous active NNE‐SSW vertical fractures. Seismicity and tectonic structures suggest a westward propagation of deformation and the growth at depth of incipient faults, comprising a NNE‐SSW sinistral fault zone in depth that is connected upward with NW‐SE vertical and normal faults. This recent fault zone is segmented and responsible for the seismicity in 1993–1994 in the coastal area, in 2004 onshore, and in 2016–2017 offshore. Insights for seismic hazard assessment point to the growth of recent faults that could produce potentially higher magnitude earthquakes than the already formed faults.
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Galimany E., M. Baeta, M. Ramón
Aquaculture, 497, 357-363. DOI: 10.1016/j.aquaculture.2018.08.005 (BibTeX: galimany.etal.2018a)
Resum: Veure
Interest in sea cucumber aquaculture is increasing worldwide for both consumption and ecological purposes. In the NW Mediterranean there is only one commercially exploited and edible sea cucumber, Parastichopus regalis, whose muscles are considered a culinary delicacy. With the aim to understand the potential for P. regalis to be grown in aquaculture facilities, we studied its resistance to the high temperature conditions that characterize the Mediterranean mariculture facilities. The immune response of adult P. regalis exposed to different temperatures (18 °C, 23 °C and 28 °C) was compared to the response to its natural environmental conditions (13 °C) during a 2-week period. Moreover, the immune response after a 1-week recovery period was also investigated. Mortality and coelomocyte characteristics and functions were analyzed, i.e. phagocytosis and dead coelomocytes. Results showed that 90% of the sea cucumbers exposed to 28 °C died before 48 h and at 23 °C they had 50% survivorship after 2 weeks of exposure. The proportion of coelomocyte types did not change during the study for animals exposed to 18 °C or 23 °C. Coelomocyte density increased throughout the experiment at 23 °C for sea cucumbers exposed to both control and high temperature. However, high temperature P. regalis exposed to 23 °C had significantly less phagocytic and dead coelomocytes during the two weeks of exposure. After a 1-week recovery period, the differences found between temperatures disappeared, except that the phagocytic capacity of the coelomocytes exposed to 23 °C was still lower than controls. In summary, P. regalis seems to have a maximum thermal tolerance below 23 °C, above which their survival is compromised. Thus, the use of P. regalis for aquaculture purposes should be constrained to areas where temperatures do not exceed 23 °C throughout the year.
Paraules clau: Echinoderm; Immunology; Mediterranean Sea; Thermal stress
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Olmedo E., I. Taupier-Letage, A. Turiel, A. Alvera-Azcárate
Remote Sensing, 10, 485, 1-24. DOI: 10.3390/rs10030485 (BibTeX: olmedo.etal.2018)
Resum: Veure
A new methodology using a combination of debiased non-Bayesian retrieval, DINEOF (Data Interpolating Empirical Orthogonal Functions) and multifractal fusion has been used to obtain Soil Moisture and Ocean Salinity (SMOS) Sea Surface Salinity (SSS) fields over the North Atlantic Ocean and the Mediterranean Sea. The debiased non-Bayesian retrieval mitigates the systematic errors produced by the contamination of the land over the sea. In addition, this retrieval improves the coverage by means of multiyear statistical filtering criteria. This methodology allows obtaining SMOS SSS fields in the Mediterranean Sea. However, the resulting SSS suffers from a seasonal (and other time-dependent) bias. This time-dependent bias has been characterized by means of specific Empirical Orthogonal Functions (EOFs). Finally, high resolution Sea Surface Temperature (OSTIA SST) maps have been used for improving the spatial and temporal resolution of the SMOS SSS maps. The presented methodology practically reduces the error of the SMOS SSS in the Mediterranean Sea by half. As a result, the SSS dynamics described by the new SMOS maps in the Algerian Basin and the Balearic Front agrees with the one described by in situ SSS, and the mesoscale structures described by SMOS in the Alboran Sea and in the Gulf of Lion coincide with the ones described by the high resolution remotely-sensed SST images (AVHRR).
Paraules clau: sea surface salinity; remote sensing; mediterranean sea; smos; alboran sea; data processing; quality assessment
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Nguyen T.V., G.E. Rotllant, S.F. Cummins, A.l Elizur, T. Ventura
Frontiers in Endocrinology, 9, 430. DOI: 10.3389/fendo.2018.00430 (BibTeX: nguyen.etal.2018a)
Resum: Veure
Multiple biological processes across development and reproduction are modulated by neuropeptides that are predominantly produced and secreted from an animal\'s central nervous system. In the past few years, advancement of next-generation sequencing technologies has enabled large-scale prediction of putative neuropeptide genes in multiple non-model species, including commercially important decapod crustaceans. In contrast, knowledge of the G protein-coupled receptors (GPCRs), through which neuropeptides act on target cells, is still very limited. In the current study, we have used in silico transcriptome analysis to elucidate genes encoding neuropeptides and GPCRs in the Norway lobster (Nephrops norvegicus), which is one of the most valuable crustaceans in Europe. Fifty-seven neuropeptide precursor-encoding transcripts were detected, including phoenixin, a vertebrate neurohormone that has not been detected in any invertebrate species prior to this study. Neuropeptide gene expression analysis of immature and mature female N. norvegicus, revealed that some reproduction-related neuropeptides are almost exclusively expressed in immature females. In addition, a total of 223 GPCR-encoding transcripts were identified, of which 116 encode GPCR-A (Rhodopsin), 44 encode GPCR-B (Secretin) and 63 encode other GPCRs. Our findings increase the molecular toolbox of neural signaling components in N. norvegicus, allowing for further advances in the fisheries/larvae culture of this species.
Paraules clau: Crustacea; Data mining; Neurohormone; Neuropeptides; Neuropeptidome; GPCRs; Phoenixin
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Vassalli M., A. Penna, F. Sbrana, S. Casabianca, N. Gjeci, S. Capellacci, V. Asnaghi, E. Ottaviani, V. Giussani, L. Pugliese, C. Jauzein, R. Lemée, L. Açaf, M.A. Hachani, S. Turki, M. Abboud-Abi Saab, A. Fricke, L. Mangialajo, R. Bertolotto, C. Totti, S. Accoroni, E. Berdalet, M. Vila, M. Chiantore
Ecological Indicators, 85, 1092-1100. DOI: 10.1016/j.ecolind.2017.07.063 (BibTeX: vassalli.etal.2018)
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Gasol J.M., D.L. Kirchman
In: Microbial Ecology of the Ocean, Third edition, Ed. J.M. Gasol, D.L. Kirchman. Wiley-Blackwell. Chap. 1. 1-46. ISBN: 978-1-119-10718-7 (BibTeX: gasol.kirchman.2018g)
Resum: Veure
Microbes are everywhere in large numbers. They were on Earth ca. 4 billion years ago, and they will be on Earth long after multicellular eukaryotes go extinct. In some environments they are the only living beings around because they can thrive in hot and cold environments; they develop inside rocks and can tolerate toxins and ultraviolet (UV) radiation. Covering 3.6 × 10 11km2 (71% of the Earth surface) and reaching a depth of 3.7 km on average, the marine habitat is likely the largest ecosystem on Earth. It is where all life started. Today, the ocean habitat is teeming with morphologically, genetically, and functionally diverse microbes. Half of the primary production in the planet occurs in the ocean (Field et al. 1998), 90% of which is done by microorganisms (Duarte and Cebrián 1996). They are also responsible for most of the ocean respiration and are crucial in most, if not all, key transformations in the cycles of nitrogen, phosphorus, sulfur, iron, and other metals. [...]
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Glibert P.M., E. Berdalet, M. Burfort, G. Pitcher, M. Zhou
In: Global Ecology and Oceanography of Harmful Algal Blooms, Ecological Studies - Analysis and Synthesis Series. Vol. 232. Ed. Glibert, P.M., Berdalet, E., Burfort, M., Pitcher, G., M. Zhou. Springer International Publishing AG, Switzerland. Chap. 1. 3-7. DOI: 10.1007/978-3-319-70069-4_1 ISBN: 978-3-319-70069-4 (BibTeX: glibert.etal.2018c)
Resum: Veure
This volume on the Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB) Programme is aimed at synthesizing the broad range of research and activities that took place during the nearly two decades of the international programme bearing this acronym. It is, however, but a snapshot into the diversity of work that took place all over the globe, promoted directly by GEOHAB and its core programmes, indirectly through its multiple Open Science Meetings or obliquely through the greater awareness of HABs and their impacts made known through various outreach activities, workshops and written materials. These impacts were, at least in part, a result of GEOHAB and related activities. Thus, the editorship and authorship throughout this book reflect the global reach of the GEOHAB Programme (Fig. 1.1).
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Ramírez-Pérez M., M. Twardowski, C. Trees, J. Piera, D. McKee
Journal of Geophysical Research: Oceans, 123, 720-737. DOI: http://dx.doi.org/10.1002/2017JC013453 (BibTeX: ramirezperez.etal.2018)
Resum: Veure
A deconvolution approach is presented to use spectral light absorption and attenuation data to estimate the concentration of the major nonwater compounds in complex shelf sea waters. The inversion procedure requires knowledge of local material-specific inherent optical properties (SIOPs) which are determined from natural samples using a bio-optical model that differentiates between Case I and Case II waters and uses least squares linear regression analysis to provide optimal SIOP values. A synthetic data set is used to demonstrate that the approach is fundamentally consistent and to test the sensitivity to injection of controlled levels of artificial noise into the input data. Self-consistency of the approach is further demonstrated by application to field data collected in the Ligurian Sea, with chlorophyll (Chl), the nonbiogenic component of total suspended solids (TSSnd), and colored dissolved organic material (CDOM) retrieved with RMSE of 0.61 mg m -3, 0.35 g m -3, and 0.02 m -1, respectively. The utility of the approach is finally demonstrated by application to depth profiles of in situ absorption and attenuation data resulting in profiles of optically significant constituents with associated error bar estimates. The advantages of this procedure lie in the simple input requirements, the avoidance of error amplification, full exploitation of the available spectral information from both absorption and attenuation channels, and the reasonably successful retrieval of constituent concentrations in an optically complex shelf sea.
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Martins C.P.P., F.Á. Fernández-Álvarez, R. Villanueva
Estuarine, Coastal and Shelf Science, 200, 437-448. DOI: 10.1016/j.ecss.2017.11.016 (BibTeX: martins.etal.2018a)
Resum: Veure
The eggs of the European cuttlefish, Sepia officinalis, develop attached to the seafloor in shallow water habitats and possess a relatively thick black capsule that protects them from the surrounding environment. Since embryological development may take several months, eggs are vulnerable to a variety of threats present in shallow waters, including predation. This study investigates predation of S. officinalis eggs by benthic invertebrates. Twenty-eight invertebrate species from 6 different phyla and with diverse feeding habits were tested as potential predators under laboratory conditions. We also investigated how the feeding traits of these species are related to the mechanical ability to break the egg capsule and prey upon cuttlefish embryos. Species that fed on cuttlefish eggs were the sea snail Bolinus brandaris, the crab Cancer pagurus, the hermit crab Dardanus arrosor, the lobster Homarus gammarus, the invasive blue crab Callinectes sapidus, the shrimp Squilla mantis, the sea urchins Echinus melo, Cidaris sp. and Paracentrotus lividus and the starfish Astropecten aranciacus. It is of note that C. sapidus is a potential predatory crab, which raises the concern that this invasive species may constitute a novel threat for cuttlefish eggs as more populations become established in NE Atlantic waters. Of the biological traits examined, prey capture tools in the tested species best explained the experimental feeding results, suggesting that predation of S. officinalis eggs was determined generally by a mechanical factor and highlighting the importance of the protective egg capsule against predators. However, chemosensory factors are likely to be implicated as well. Thus, this work contributes to the understanding of the ecology of early life stages of cuttlefish and the factors that can affect offspring survival and subsequently impact the recruitment of this species.
Paraules clau: Predation, eggs, cephalopod, marine invertebrates, NE Atlantic, multivariate correspondence analysis
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Berdalet E., P. Tester
In: Global Ecology and Oceanography of Harmful Algal Blooms, Ecological Studies - Analysis and Synthesis Series.. Vol. 232. Ed. Glibert, P.M., Berdalet, E., Burfort, M., Pitcher, G., M. Zhou. Springer International Publishing AG, Switzerland. Chap. 13. 261-286. DOI: 10.1007/978-3-319-70069-4_13 ISBN: 978-3-319-70069-4 (BibTeX: berdalet.tester.2018a)
Resum: Veure
The GEOHAB Core Research Project (CRP) Harmful Algal Blooms in Benthic Systems, launched in 2010, focused on toxic and noxious events associated with benthic microalgae, especially the genera Gambierdiscus and Ostreopsis. Both organisms, which produce mucus to attach to benthic substrates (macroalgae, corals, rocks, sand), seem to be expanding to temperate latitudes. Gambierdiscus species produce ciguatoxins that cause ciguatera fish poisoning in humans. Ostreopsis species produce palytoxin and analogues seldom associated with seafood intoxications in the tropics and with massive macrofauna mortalities and respiratory disorders in humans in temperate waters. This chapter summarizes recent progress and identifies future challenges in this research field.
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Raine R., E. Berdalet, H. Yamazaki, I. Jenkinson, B. Reguera
In: Global Ecology and Oceanography of Harmful Algal Blooms, Ecological Studies - Analysis and Synthesis Series.. Vol. 232. Ed. Glibert, P.M., Berdalet, E., Burfort, M., Pitcher, G.. Springer International Publishing AG, Switzerland. Chap. 9. 165-186. DOI: 10.1007/978-3-319-70069-4_9 ISBN: 978-3-319-70069-4 (BibTeX: raine.etal.2018a)
Resum: Veure
This chapter synthesizes progress achieved in the understanding of the dynamics of harmful algal blooms (HABs) under the auspices of the GEOHAB Core Research Project HABs in Stratified Systems. A variety of aquatic environments are considered, where small-scale hydrographic features may be encountered in stratified water columns. A special emphasis is put on subsurface thin-layer structures, which, thanks to advances in fine-resolution sampling and observation methods, have dramatically changed our comprehension of HAB events. The importance of small-scale physical–biological interactions as well as chemically driven relationships between HAB species and components of the food web are also key topics addressed. Research priorities are identified and the potential offered by new approaches and advanced instrumentation is discussed.
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Isla E., D.J. DeMaster
Geochimica et cosmochimica acta, 242, 34-50. DOI: 10.1016/j.gca.2018.08.011 (BibTeX: isla.demaster.2018a)
Resum: Veure
Labile organic carbon (LOC) dynamics (i.e., of recently produced, planktonic material) and sediment dynamics were studied in the seabed using naturally occurring 14Corg and 210Pb measurements in the region where the Larsen Ice Shelves A and B were floating almost two decades ago. A non-steady-state diagenetic model was used to estimate sediment mixing coefficients as well as LOC fluxes to the seabed and LOC turnover times (i.e., mean residence times) in a suite of 14 sediment cores from the continental shelf, including a glacial trough. At four of the stations, cores were collected during 2007 and 2011 cruises, enabling a time-series approach for understanding the evolution of sedimentary processes and LOC dynamics in the deposits below a collapsed ice shelf. Sediment mixing coefficients, based on non-steady-state 210Pb profiles, varied between 0.01 cm2 y−1 and 1.6 cm2 y−1 in these post-ice shelf sediments. These values were similar to those found in polar deep-sea environments, where sedimentary conditions are less dynamic than in shallower provinces. LOC, whose abundance decreased uniformly with depth, was detected to depths ranging from 2 to 16 cm, with LOC seabed inventories varying from 1.5 to 22 mg LOC cm−2. Excess 210Pb and LOC fluxes were relatively uniform across the study area suggesting that similar particle fluxes have taken place within the Larsen system since the disintegration of the various ice shelves. The LOC mean residence time at the different stations varied from 3 y to >60 y. The 14Corg approach, calculating LOC content based on a two-end member model with planktonic 14Corg as the labile carbon end member, most closely correlated with the lipid content of the sediment, which has been considered one of the best descriptors of reactive organic matter readily available to benthic consumers. We suggest that the irregular combination of sea ice coverage, organic matter production and supply to the sea floor introduce scatter in the determination of sediment and LOC dynamics such that short-term temporal (<5 years) and spatial trends could not be readily resolved.
Paraules clau: Antarctica; Ice shelf collapse; Labile organic carbon; Biogeochemistry; Marine sediment; Larsen ice shelves; 14C; 210Pb
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Villarino E., J.R. Watson, B. Jönsson, J.M. Gasol, G. Salazar, S.G. Acinas, M. Estrada, R. Massana, R. Logares, C.R. Giner, M.C. Pernice, M.P. Olivar, L. Citores, J. Corell, N. Rodríguez-Ezpeleta, J.L. Acuña, A. Molina-Ramírez, I. González-Gordillo, A. Cózar, E. Martí, J.A. Cuesta, S. Agustí, E. Fraile-Nuez, C.M. Duarte, X. Irigoien, G. Chust
Nature Communications, 9, 142, 1-13. DOI: 10.1038/s41467-017-02535-8 (BibTeX: villarino.etal.2018a)
Resum: Veure
Global patterns of planktonic diversity are mainly determined by the dispersal of propagules with ocean currents. However, the role that abundance and body size play in determining spatial patterns of diversity remains unclear. Here we analyse spatial community structure - β-diversity - for several planktonic and nektonic organisms from prokaryotes to small mesopelagic fishes collected during the Malaspina 2010 Expedition. β-diversity was compared to surface ocean transit times derived from a global circulation model, revealing a significant negative relationship that is stronger than environmental differences. Estimated dispersal scales for different groups show a negative correlation with body size, where less abundant large-bodied communities have significantly shorter dispersal scales and larger species spatial turnover rates than more abundant small-bodied plankton. Our results confirm that the dispersal scale of planktonic and micro-nektonic organisms is determined by local abundance, which scales with body size, ultimately setting global spatial patterns of diversity.
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Lafosse M., C. Gorini, P. Le Roy, B. Alonso, E. d’Acremont, G. Ercilla, M. Rabineau, J.T. Vázquez, A. Rabaute, A. Ammar
Marine and Petroleum Geology, 97, 370-389. DOI: 10.1016/j.marpetgeo.2018.07.022 (BibTeX: lafosse.etal.2018a)
Resum: Veure
In active basins, tectonics can segment the continental shelf and control its stratigraphic architecture and physiography. Segmentation can explain the local evolution and morphology of the continental shelf because of sea-level variations, local tectonic segmentation and hydrodynamic processes. Here we investigate the tectonically active Morocco continental margin (southern Alboran Sea) using high-resolution seismic profiles and multibeam bathymetric data. The active faults bounding the transtensive Nekor basin triggered the segmentation of the shelf into three sectors showing different subsidence rates: a western sector corresponding to an extensive fault relay, a central sector corresponding to the subsiding Al-Hoceima Bay and an eastern sector corresponding to the footwall of the Trougout senestral normal fault. Results show that the staircase morphology of the shelf corresponds to successive submarine terraces at the shelf edge (ST1), mid-shelf (ST2) and inner-shelf (ST3) around −110 m,-80 m, and −40 to −20 m deep, respectively. The terraces correspond to the top of prograding wedges seaward and are erosive landward. They are correlated with stillstand from the Last Glacial Maximum to the Holocene highstand. Above the terraces, sub-aqueous dune fields are interpreted as degraded and deposited during the post-glacial transgression. In the central sector, typical delta front seafloor undulations on the shelf and crescent shaped bedforms at the head of marine incisions on the upper slope denote a fluvial influence during the Holocene. Seismic stratigraphy analysis revealed the preservation of six seismic units bounded by polygenic regional unconformities (S1, S2, S3, S4 and S5). Based on comparison with other Mediterranean margins, S1 to S5 are attributed to 4th order maximum regressive surface. We discuss the local preservation of the system tracts as a function of the vertical motion and the physiography of this tectonically active domain. This study provides useful clues for future local paleo-seismic analysis and to advance our understanding of sedimentary processes in active areas.
Paraules clau: Seismic stratigraphy; Active tectonic; Pleistocene; Continental shelf; Swath bathymetry; Geomorphology; Western Mediterranean
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Lin C.-H., Y.-P. Chiang, V.M. Tuset, A. Lombarte, A. Girone
Geobios, 51, 4, 335-358. DOI: 10.1016/j.geobios.2018.06.002 (BibTeX: lin.etal.2018a)
Resum: Veure
Despite extensive studies on the taxonomy of fossil otoliths, the diversity of late Quaternary to Recent sea bottom otolith assemblages remains largely unexplored. Otolith assemblages from bottom sediments of the North-eastern Atlantic (NE Atlantic), central Mediterranean, and Red Sea were described based on a dataset of 9696 identifiable otoliths. Diversity estimators were computed and taxonomic compositions were compared against geographical site and depth gradient. Several species from the Red Sea show previously unnoticed range extensions or ancient occurrences, suggesting that the otolith assemblage requires further exploration in this region. The diversity is high in the NE Atlantic and central Mediterranean, whereas Red Sea assemblages are dominated by few taxa. We find that, departing from Modern fish communities, the richness of otolith taxa peaks at mid-water depths (500-1500 m) and decreases at depths > 2000 m. The lower diversity at shallow water suggests environments not favorable for otolith preservation. The assemblages are geographically distinct, due to unique combinations of mesopelagic taxa specific to each sample area, though areas in the central Mediterranean and middle-latitude NE Atlantic share many taxa. Depth does not seem to structure otolith assemblages in the central Mediterranean because the otolith composition in this region is highly variable at depths < 500 m but poorly variable at greater depths. The discrepancies between otolith thanatocoenoses and fossil assemblages and the potential application for reconstructing ancient fish communities are discussed. Illustrating otoliths that are rarely found in the literature, this study is the first descriptive and comparative diversity analysis on Recent otolith assemblages for the regions of interest.
Paraules clau: Fish community; Taxonomy; Diversity estimator; Multivariate analysis; Paleoecology; Biogeography
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Figueroa R.I., M. Estrada, E. Garcés
Harmful Algae, 73, 44-57. DOI: 10.1016/j.hal.2018.01.006 (BibTeX: figueroa.etal.2018a)
Resum: Veure
In coastal and offshore waters, Harmful Algal Blooms (HABs) currently threaten the well-being of coastal countries. These events, which can be localized or involve wide-ranging areas, pose risks to human health, marine ecosystems, and economic resources, such as tourism, fisheries, and aquaculture. Dynamics of HABs vary from one site to another, depending on the hydrographic and ecological conditions. The challenge in investigating HABs is that they are caused by organisms from multiple algal classes, each with its own unique features, including different life histories. The complete algal life cycle has been determined in <1% of the described species, although elucidation of the life cycles of bloom-forming species is essential in developing preventative measures. The knowledge obtained thus far has confirmed the complexity of the algal life cycle, which is composed of discrete life stages whose morphology, ecological niche (plankton/benthos), function, and lifespan vary. The factors that trigger transitions between the different stages in nature are mostly unknown, but it is clear that an understanding of this process provides the key to effectively forecasting bloom recurrence, maintenance, and decline. Planktonic stages constitute an ephemeral phase of the life cycle of most species whereas resistant, benthic stages enable a species to withstand adverse conditions for prolonged periods, thus providing dormant reservoirs for eventual blooms and facilitating organismal dispersal. Here we review current knowledge of the life cycle strategies of major groups of HAB producers in marine and brackish waters. Rather than providing a comprehensive discussion, the objective was to highlight several of the research milestones that have changed our understanding of the plasticity and frequency of the different life cycle stages as well as the transitions between them. We also discuss the relevance of benthic and planktonic forms and their implications for HAB dynamics.
Paraules clau: Harmful algal species, Life history, Harmful algal blooms, Environmental and physiological factors, Resting stages, Management, Models
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Guerrero E., J.-M. Gili, J. Grinyó, V. Raya, A. Sabatés
Plos One. Open acces, 13, 5, e0196431. DOI: 10.1371/journal.pone.0196431 (BibTeX: guerrero.etal.2018e)
Resum: Veure
In the present work, possible long-term changes in the planktonic cnidarian community were investigated by analyzing (1) species and community spatial distribution patterns, (2) variations in abundance and (3) changes in species richness during three mesoscale surveys representative of the climatic and anthropogenic changes that have occurred during the last three decades (years: 1983, 2004 and 2011) in the NW Mediterranean. These surveys were conducted during the summer (June) along the Catalan coast. All surveys covered the same area, used the same sampling methodology, and taxonomic identification was conducted by the same team of experts. An increase in the abundance of total cnidaria was found from 1983 to 2011. The siphonophore Muggiaea atlantica and the hydromedusa Aglaura hemistoma were the most abundant species, while Muggiaea kochii presented the largest abundance increment over time. Temperature was the main environmental parameter driving significant differences in the cnidarian community composition, abundance and spatial distribution patterns among the surveys. Our results suggest that in the current climate change scenario, warm-water species abundances will be positively favored, and the community will suffer changes in their latitudinal distribution patterns. We consider it extremely important to study and monitor gelatinous zooplankton in mesoscale spatial areas to understand not only long-term changes in abundances but also changes in their spatial distributions since spatial changes are sensitive indicators of climate change
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López-Escardó D., J. Paps, C. de Vargas, R. Massana, I. Ruiz-Trillo, J. del Campo
Scientific Reports, 8, 9106, 1-14. DOI: 10.1038/s41598-018-27509-8 (BibTeX: lopezescardo.etal.2018)
Gasol J.M., D.L. Kirchman
Ed. J.M. Gasol, D.L. Kirchman. Wiley-Blackwell. ISBN: 978-1-119-10718-7 (BibTeX: gasol.kirchman.2018d)
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Castejón D., J. Alba-Tercedor, G. Rotllant, E. Ribes, M. Durfort, G. Guerao
Scientific Reports, 8, 14399. DOI: 10.1038/s41598-018-32709-3 (BibTeX: castejon.etal.2018a)
Resum: Veure
Traditionally, the internal morphology of crustacean larvae has been studied using destructive techniques such as dissection and microscopy. The present study combines advances in micro-computed tomography (micro-CT) and histology to study the internal morphology of decapod larvae, using the common spider crab (Maja brachydactyla Balss, 1922) as a model and resolving the individual limitations of these techniques. The synergy of micro-CT and histology allows the organs to be easily identified, revealing simultaneously the gross morphology (shape, size, and location) and histological organization (tissue arrangement and cell identification). Micro-CT shows mainly the exoskeleton, musculature, digestive and nervous systems, and secondarily the circulatory and respiratory systems, while histology distinguishes several cell types and confirms the organ identity. Micro-CT resolves a discrepancy in the literature regarding the nervous system of crab larvae. The major changes occur in the metamorphosis to the megalopa stage, specifically the formation of the gastric mill, the shortening of the abdominal nerve cord, the curving of the abdomen beneath the cephalothorax, and the development of functional pereiopods, pleopods, and lamellate gills. The combination of micro-CT and histology provides better results than either one alone.
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Canals O., R. Massana, J.L. Riera, V. Balagué, H. Salvadó
New Biotechnology, 43, 3-12. DOI: 10.1016/j.nbt.2017.05.003 (BibTeX: canals.etal.2018)
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Martínez J., V. González-Gambau, A. Turiel
IEEE Geoscience and Remote Sensing Letters, 15, 7, 1060-1064. DOI: 10.1109/LGRS.2018.2818285 (BibTeX: martinez.etal.2018b)
Resum: Veure
Since the beginning of the soil moisture and ocean salinity mission, the pervading presence of radio frequency interferences (RFI) has been one of the most problematic issues. The effect of an RFI is not just a hot spot but also six tails along the three main axes, and the general presence of ripples which degrade the quality of L1 brightness temperature snapshots. The standard mitigation technique is to apply an apodization (Blackman), but such a low-pass filter leaves traces of the tails and spreads the signal of the main lobes. New RFI mitigation techniques, such as nodal sampling, are very effective in reducing the impact of tails and ripples, but in some cases they lead to the spread of the RFI main lobe, with a significant loss of data on the affected area. In this letter, we propose a new technique to reduce their spread by an adaptive thresholding on a bandpass filtered version of the snapshot, with a significant recovery of data
Paraules clau: Imaging; Interferometry; Remote sensing; Radio frequency interferences (RFI); Signal processing; Soil moisture and ocean salinity (SMOS).
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Riera R., V.M.Tuset, R. Betancur-R, A. Lombarte, C. Marcos, A. Pérez-Ruzafa
Progress in Oceanography, 165, 100-109. DOI: 10.1016/j.pocean.2018.05.003 (BibTeX: riera.etal.2018a)
Resum: Veure
Coastal lagoons are marine ecosystems spread worldwide with high ecological value; however, they are increasingly becoming deteriorated as a result of anthropogenic activity. Their conservation requires a better understanding of the biodiversity factors that may help identifying priority areas. The present study is focused on 37 Mediterranean coastal lagoons and we use predictive modelling approaches based on Generalized Linear Model (GLM) analysis to investigate variables (geomorphological, environmental, trophic or biogeographic) that may predict variations in alpha-diversity. It included taxonomic diversity, average taxonomic distinctness, and phylogenetic and functional diversity. Two GLM models by index were built depending on available variables for lagoons: in the model 1 all lagoons were used, and in the model 2 only 23. All alpha-diversity indices showed variability between lagoons associated to exogenous factors considered. The biogeographic region strongly conditioned most of models, being the first variable introduced in the models. The salinity and chlorophyll a concentration played a secondary role for the models 1 and 2, respectively. In general, the highest values of alpha-diversities were found in northwestern Mediterranean (Balearic Sea, Alborán Sea and Gulf of Lion), hence they might be considered “hotspots” at the Mediterranean scale and should have a special status for their protection.
Paraules clau: Coast Fish, Taxonomic diversity, Functional diversity, Phylogenetic diversity, GLM model, Mediterranean Sea
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Castejon Bueno D.,
PhD thesis. Director/es: G. Guerao, G. Rotllant. (BibTeX: castejonbueno.2018b)
Resum: Veure
The present Doctoral Thesis is framed in the research toward the profitable culture of the common spider crab (Maja brachydactyla Balss, 1922) focusing in two topics: the improvement of the larval culture and the description of the digestive system. Our results conclude that the optimal parameters were: 21 ± 1 °C, 35 ± 1 psu and a daily light-dark cycle. Temperature influences the duration of the larval development, salinity the survival and light have a poor influence. This species does not have special requirements for settlement. The basic morphology of the digestive system is conserved during all the life stages. The main differences rely on the higher development of connective and muscles in adult specimens comparing to larval stages. The biggest change occur in the stomach, since acquires cardiac sacs, ossicle system and gastric mill after the molt to megalopa. The caeca of the midgut gland (hepatopancreas) are very similar between larvae and adults, but their number increases from fourteen in the larvae to tens of thousands in the adults. The esophagus and hindgut tract are characterized by the presence of a cuticle with microspines and rosette glands in the connective. The midgut gland, midgut tract and midgut caeca are very rich in microvilli. The midgut gland realizes absorptive and secretory functions, the midgut tract secretes the peritrophic membrane and the midgut caeca realizes an important secretory activity. For first time, the \"micro-apocrine\" secretion is described in decapods
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Tuset V.M., M.P. Olivar, J.L. Otero-Ferrer, C. López-Pérez, P.A. Hulley, A. Lombarte
Deep-Sea Research. Part I: Oceanographic Research Papers, 138, 46-59. DOI: 10.1016/j.dsr.2018.07.005 (BibTeX: tuset.etal.2018b)
Resum: Veure
Insight into the evolutionary radiation of organisms is partly underpinned by theories on the adaptive divergence of sensory systems, and the ecological, physiological, and behavioural adaptations to both environmental conditions and to competition for limited resources. The aim of this study is to determine the degree of phenotypic variability and functional niche overlap between Diaphus (Myctophidae) species that could account for the high level of speciation within this genus. The Diaphus specimens which were used for our study, were obtained from a survey transect across the central Atlantic Ocean. We analysed the morpho-functional features of fish body shape and sagittae otolith shape of these specimens. Although our study included only 9 species, our findings revealed a high degree of morpho-functional variability in the fish body and otolith shapes, both of which are coupled with the variations of the bioluminescent organs of the head, especially the suborbital organ situated under eye and called So-photophore. Two morphotypes were identified: ‘Diaphus-deep’ (morphotype-1) with an So-photophore, and defined by a larger otolith and a deep body, larger head, eye and mouth; and ‘Diaphus-slender’ (morphotype-2) without an So-photophore, and characterized by an increased development of anterior-dorsal margin of otolith and an enlarged body with small head, eye and mouth. Our analyses supported both the sensory drive and niche hypotheses as forces promoting the radiation within the genus Diaphus. Future studies involving a greater number of species are necessary to advance the knowledge of speciation mechanisms in myctophids.
Paraules clau: Diaphus; Lanternfishes; Morphological differentiation; Functional niche; Morphotypes
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Grinyó J., A. Gori, P.J. López-González, A. Santín, P. Baena, J.M. Gili
Marine Biology Research, 14, 1, 30-40. DOI: 10.1080/17451000.2017.1375118 (BibTeX: grinyo.etal.2018)
Resum: Veure
Morphological variability in gorgonians is frequent and commonly associated with habitat variability, often resulting in segregated morphotypes. Paramuricea macrospina is an endemic Mediterranean gorgonian species found on rocky bottoms between 40 and 160 m depth and has recently been reported as one of the most abundant species in continental shelf and shelf edge environments. Three different chromatic forms of P. macrospina were observed in the Menorca Channel: a yellow form and a light purple form occurring on maërl beds of the continental shelf, and a dark purple form occurring on rocky substrates of the shelf edge. The objective of the present work is to verify if these P. macrospina forms may represent distinct taxonomic units by analysing differences in colony morphology and sclerite size and shape of the three chromatic forms. No significant differences were found in colony shape, suggesting that environmental variability between the continental shelf and the shelf edge is not influential enough to significantly alter colony morphology. Significant differences in sclerite size and shape were found amongst all forms, suggesting that sclerites may be influenced by environmental conditions. However, the co-occurrence of the yellow and light purple forms side by side on the continental shelf may indicate a certain degree of genetic differentiation.
Paraules clau: Paramuricea macrospina; Sclerite morphology; Gorgonian; Colonial morphology
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Dallarés S., N. Carrasco, D. Álvarez-Muñoz, M. Rambla-Alegre, M. Solé
Environmental Science and Pollution Research, 25, 36, 36745–36758. DOI: 10.1007/s11356-018-3614-6 (BibTeX: dallares.etal.2018a)
Resum: Veure
Bivalves have proved to be useful bioindicators for environmental pollution. In the present study, mussels (Mytilus galloprovincialis), cockles (Cerastoderma edule), and razor shells (Solen marginatus) were collected in the Ebro Delta, an extensive area devoted to rice farming and affected by pesticide pollution, from April to July, the heaviest rice field treatment period. Possible effects of pollution were assessed through biochemical markers (carboxylesterase (CE), antioxidant and neurotoxicity-related enzymes, and lipid peroxidation levels). Data on environmental variables, bivalve reproductive condition, and presence of organic pollutants, marine phycotoxins, pathogens, or histopathological conditions in bivalve’s tissues were also evaluated. Although the bioaccumulated pesticides did not explain the patterns observed for biochemical responses, the obtained results point to an effect of environmental pesticide pollution on enzymatic markers, with a prominent contribution of CE to such changes. Mussels and razor shells provided a more sensitive biochemical response to pollution than cockles. Environmental variables, bivalve reproductive condition, and marine phycotoxins did not seem to have a relevant effect on the biomarkers assessed.
Paraules clau: Mussel; Cockle; Razor shell; Biomarkers; Contaminants; Pesticides; Histology; Phycotoxins
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Yokes M., V. Andreou, R. Bakiu, S. Bonanomi, J. Camps, G. Christidis, F. Crocetta, I. Giovos, A. Gori, T. Juretic, S. Ünsal Karhan, S. Katsanevakis, E. Kytinou, J. Langeneck, L. Lipej, M. Maximiadi, N. Michailidis, E. Mitsou, A. Nicolaidou, S. Petrovic, P. Prado, A. Santín, K. Teneketzis, I. Thasitis, V. Tirelli, D. Trkov, E. Troplini, K. Tsiamis, A. Vannucci
Mediterranean Marine Science, 19, 673-689. DOI: 10.12681/mms.19386 (BibTeX: yokes.etal.2018)
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Baki Yokeş M., Va. Andreou, R. Bakiu, S. Bonanomi, J. Camps, G. Christidis, F. Crocetta, I. Giovos, A. Gori, T. Juretić, S. Ünsal Karhan, S. Katsanevakis, E. Kytinou, J. Langeneck, L. Lipej, M. Maximiadi, N. Michailidis, E. Mitsou, A. Nicolaidou, S. Petović, P. Prado, A. Santín, K. Teneketzis, I. Thasitis, V. Tirelli, D. Trkov, E. Troplini, K. Tsiamis, A. Vannucci
Mediterranean Marine Science, 19, 3, 673-689. DOI: 10.12681/mms.19386 (BibTeX: bakiyoke.etal.2018a)
Resum: Veure
In the present article, new records are given for 18 species (6 native, 9 alien and 3 cryptogenic), belonging to 5 Phyla (i.e. Chlorophyta, Cnidaria, Annelida, Mollusca and Chordata), from 8 Mediterranean countries: Spain: A large population of Polycerella emertoni reported from the Ebro Delta, the presence of Spinimuricea klavereni is confirmed for the first time in the Catalan coast; Italy: the new record of Cryptonome turcica extends its distribution to the western Mediterranean Sea, the findings of Mawia benovici constitute the southernmost record of this species in the Adriatic Sea; Slovenia: second record of the alien seaslug Cuthona perca in the Mediterranean Sea; Montenegro: Styela plicata communities were recorded in Boka Kotorska Bay; Albania: the native great torpedo ray Tetronarce nobiliana recorded for the first time in Albanian waters; Greece: first record of Lagocephalus sceleratus in the Greek side of the Adriatic, the records of Cassiopea andromeda and Pterois miles are first records of these species from the Ionian Sea, the colonial ascidians Aplidium coeruleum and Didemnum protectum are recorded for the first time in the Eastern Mediterranean, an extremely abundant population of Melibe viridis is found in Messolonghi lagoon, the record of Synchiropus sechellensis is the range expansion of this species in Greek Seas, Acetabularia caliculus is recorded for the first time from Greece; Cyprus: first records of Callionymus filamentosus and Haminoea cyanomarginata from the island; Turkey: the presence of Berthellina citrina in the Mediterranean is confirmed.
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Dall’Osto M., D.C.S. Beddows, A. Asmi, L. Poulain, L. Hao, E. Freney, J.D. Allan, M. Canagaratna, M. Crippa, F. Bianchi, G. de Leeuw, A. Eriksson, E. Swietlicki, H.C. Hansson, J.S. Henzing, C. Granier, K. Zemankova, P. Laj, T. Onasch, A. Prevot, J. P. Putaud, K. Sellegri, M. Vidal, A. Virtanen, R. Simo, D. Worsnop, C. O’Dowd, M. Kulmala, R.M. Harrison.
Scientific Reports, 8, 1482, 1-11. DOI: 10.1038/s41598-017-17343-9 (BibTeX: dallosto.etal.2018a)
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Marañón E., M. Pérez-Lorenzo, P. Cermeño, B. Mouriño-Carballido
ISME Journal, 1-10. DOI: 10.1038/s41396-018-0105-1 (BibTeX: maranon.etal.2018)
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Barría C., A.I. Colmenero, A. del Rosario, F. del Rosario
Journal of Applied Ichthyology, 34, 3, 684-686. DOI: 10.1111/jai.13644 (BibTeX: barria.etal.2018g)
Resum: Veure
The smalltooth sand tiger shark Odontaspis ferox (Odontaspididae) is a demersal offshore species (Acuña-Marrero, Zimmerhackel, Mayorga, & Hearn, 2013) inhabiting deep waters along continental and oceanic shelves and upper slopes, at depths ranging from 10 to 883 m (Fergusson, Graham, & Compagno, 2008). It has a circumglobal but patchy distribution throughout warm temperate and tropical waters (Compagno, 2001); and it is considered unusual encountered, or naturally has low population numbers (Bonfil, 1995). Little is known on the biology and ethology of O. ferox. The largest recorded size at maturity for males is 250 cm total length (TL) and 350 cm TL for females (Fergusson et al., 2008). This species has a low reproductive capacity (two pups every 2 years) and Compagno (2001) suggested uterine cannibalism in the form of oophagy. Although O. ferox is not a targeted species it is incidentally caught by bottom gill nets, longlines and trawlers (Fergusson et al., 2008). This, together with its low fecundity and small population, make this species highly vulnerable to exploitation and potentially susceptible to local extinction; and it is listed as Vulnerable in the International Union for Conservation of Nature (Graham et al., 2016). The Canary Islands records include two large females found floating dead in Lanzarote and Fuerteventura (Fergusson et al., 2008), and three more specimens preserved at the Museo Insular (Brito, 1991). This work presents the first reports of live specimens of O. ferox from El Hierro with comments about their behaviour, return rates and site fidelity.
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Peña M., R. Villanueva, A. Escánez, A. Ariza
Journal of Marine Systems, 179, 31-37. DOI: 10.1016/j.jmarsys.2017.11.003 (BibTeX: pena.etal.2018b)
Resum: Veure
Squids are fast swimmers that are difficult to catch by nets and to record with echosounders in the open ocean. A rare detection of orangeback flying squid Sthenoteuthis pteropus in the Central Eastern Atlantic Ocean off the coast of Senegal was accomplished during the MAFIA oceanographic survey carried out between Brazil and the Canary Islands in April 2015. Although net sampling did not yield any subadult or adult individuals, dozens were visually detected from the vessel jumping out of the water at night and displaying their characteristic dorsal photophore patch. A few squids were caught with fishing lines and identified at the species level. The acoustic echograms revealed distinctive previously unobserved acoustic echotraces that seemed to be caused by those squids, which were the only new species detected at that station (over a bottom depth ranging from 4010 to 5215 m, between 10° 45′ N 22° 41′ W and 10° 53′ N 22° 40′ W). The acoustic response and swimming behaviour shown by those echotraces reinforced this hypothesis. The (potentially) squid recordings dove rapidly (0.19 m/s to 0.48 m/s) from around 10 m below the mesopelagic fish layer, which had migrated to the subsurface at night (35 m depth), to depths of 70–95 m, and swam upward, apparently attacking fish from below. The morning squid migration to deeper waters (250–300 m) was also recorded acoustically. Downward movements of squid swimming at speeds of 0.22 m/s were calculated from the echogram, while the mesopelagic migrating fish swam at 0.27 m/s reaching 250 m depth. Sv120 − Sv38 averaged 2.7 ± 3.2 dB for the squid echotraces while the mesopelagic layer showed values of −8.8 ± 0.9 dB. These ranges agreed with values in the literature and from theoretical models. This study provides more insight into the migrating behaviour of oceanic squids, a species group that is poorly represented in the acoustic literature due to challenges in studying them
Paraules clau: Sthenoteuthis pteropus, behaviour, migration, mesopelagic fish, acoustics
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Ghanem R., E. Soufi Kechaou, J. Ben Souissi, J. Garrabou
Scientia Marina, 82, 1, 55-66. DOI: 10.3989/scimar.04675.07A (BibTeX: ghanem.etal.2018)
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Llanillo P.J., J.L. Pelegrí, L.D. Talley, J. Peña-Izquierdo, R.R. Cordero
Journal of Geophysical Research: Oceans, 123, 3, 1722-1744. DOI: 10.1002/2017JC013509 (BibTeX: llanillo.etal.2018)
Resum: Veure
Ventilation of the eastern South Pacific Oxygen Minimum Zone (ESP-OMZ) is quantified using climatological Argo and dissolved oxygen data, combined with reanalysis wind stress data. We (1) estimate all oxygen fluxes (advection and turbulent diffusion) ventilating this OMZ, (2) quantify for the first time the oxygen contribution from the subtropical versus the traditionally studied tropical equatorial pathway, and (3) derive a refined annual-mean oxygen budget for the ESP-OMZ. In the upper OMZ layer, net oxygen supply is dominated by tropical-equatorial advection, with more than one-third of this supply upwelling into the Ekman layer through previously unevaluated vertical advection, within the overturning component of the regional Subtropical Cell (STC). Below the STC, at the OMZ’s core, advection is weak and turbulent diffusion (isoneutral and dianeutral) accounts for 89% of the net oxygen supply, most of it coming from the oxygen-rich subtropical gyre. In the deep OMZ layer, net oxygen supply occurs only through turbulent diffusion and is dominated by the tropical-equatorial pathway. Considering the entire OMZ, net oxygen supply (3.8460.42 mmol kg21 yr21) is dominated by isoneutral turbulent diffusion (56.5%, split into 32.3% of tropical-equatorial origin and 24.2% of subtropical origin), followed by isoneutral advection (32.0%, split into 27.6% of tropical-equatorial origin and 4.4% of subtropical origin) and dianeutral diffusion (11.5%). One-quarter (25.8%) of the net oxygen input escapes through dianeutral advection (most of it upwelling) and, assuming steady state, biological consumption is responsible for most of the oxygen loss (74.2%).
Alacid E., A. Reñé
Investigación y Ciencia, 499, 48-49. (BibTeX: alacid.rene.2018a)
Resum: Veure
Las zonas costeras de todo el mundo se ven a menudo afectadas por episodios de proliferaciones algales nocivas. Estos episodios los causan mayormente microalgas del grupo de los dinoflagelados, los cuales tienen un efecto nocivo tanto para el propio ecosistema como para la economía y la salud humana debido a su toxicidad. Aunque estas proliferaciones y sus causas han sido ampliamente estudiadas, algunos de sus enemigos naturales, los parásitos, han pasado inadvertidos.
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Palanques A., P. Puig
Marine Geology, 406, 119-131. DOI: 10.1016/j.margeo.2018.09.010 (BibTeX: palanques.puig.2018a)
Resum: Veure
The effects of deep dense shelf water cascading and open sea convection on the sediment dynamics of the northwestern Mediterranean basin were studied by near-bottom moored instruments recording trapped particle fluxes, suspended particle fluxes, water properties and hydrodynamics from November 2011 to July 2012. During this period, near-bottom currents induced by winter dense water formation generated benthic storms that caused resuspension at 2450 m water depth, increasing by more than one order of magnitude the ambient suspended sediment concentrations, the trapped particle fluxes and the suspended sediment fluxes. During the preconditioning phase of the open sea convection, from December 2011 to mid-February 2012, currents (1–10 cm s−1), suspended sediment concentrations (<0.1 mg l−1), Chl-a fluorescence values (<0.063 μg l−1), trapped total mass fluxes (10–50 mg m−2 d−1) and trapped organic carbon fluxes (1–4 mg m−2 d−1) were low, and organic matter was mainly undegraded and of marine origin. Open sea convection was observed at the study site in mid-February, at the beginning of the violent mixing phase, increasing current velocities up to 26 cm s−1 and Chl-a fluorescence values up to 0.074 μg l−1, supplying particles with fresh marine organic matter content. During the last fortnight of February, two major dense shelf water cascading pulses generated Chl-a fluorescence increases (up to 0.116 μg l−1) and large suspended sediment concentration peaks (up to19 mg l−1), suspended sediment fluxes (up to 6500 mg m−2 d−1) and trapped total mass flux increases (up to 22,900 mg m−2 d−1), which were associated with benthic storms resuspension. During this phase, trapped organic carbon flux increased almost two orders of magnitude (up to 260 mg m−2 d−1), with pulses of both marine and terrestrial organic matter. The sinking and spreading phase occurred from early March to mid-June. The signal of deep dense shelf water cascading lasted past early April, and the spreading of the newly formed dense water maintained maximum currents of up to 25 cm s−1 and trapped particle fluxes of up to 2000 mg m−2 d−1 until mid-June. At the beginning of this phase, organic matter was terrestrial and several turbidity peaks occurred during current speed increases generated by benthic storms. At the end of this phase, the organic matter became less terrestrial, trapped organic carbon fluxes decreased from about 190 to 10 mg m−2 d−1 and turbidity peaks occurred with low current velocities indicating the arrival of storm tails at the mooring site. The large particle fluxes of fresh or relatively undegraded organic carbon induced by deep dense water formation during winter 2012, contributed to the “fertilization” of the northwestern Mediterranean deep benthic ecosystems.
Paraules clau: Benthic storms; Open sea convection; Dense shelf water cascading; Deep sea; Sediment transport; Seafloor resuspension
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Sabatés A., J. Salat, U. Tilves, V. Raya, J. E. Purcell, M. Pascual, J.M. Gili, V.L. Fuentes
Journal of Marine Systems, 187, 52-61. DOI: 10.1016/j.jmarsys.2018.06.013 (BibTeX: sabates.etal.2018b)
Resum: Veure
This study investigates the possible pathways for Pelagia noctiluca intrusions over the shelf to understand the interactions between jellyfish and fish larvae. To assess how the presence of P. noctiluca may influence populations of Engraulis encrasicolus and Trachurus trachurus, we analyzed the effect of environmental conditions on the abundance and spatial distribution of P. noctiluca, medusae and ephyrae, and early life stages of these two fish species along the Catalan coast. The highest concentrations of P. noctiluca were found offshore, all along the Northern Current path. Their occurrence over the shelf was associated with intrusions of open sea waters that contoured anticyclonic eddies generated by the oscillatory behaviour of the current. Anchovy larvae were found widely over the shelf, but were especially abundant in the north and in waters influenced by the Ebro river. Spatial patterns of anchovy larvae were defined better by physical environmental factors than by the presence of P. noctiluca, whose distribution clearly was determined by the circulation. The differences in environmental conditions controlling the populations of P. noctiluca and E. encrasicolus larvae prevent their general coexistence over the shelf and prey-predator interactions remained limited to the areas affected by offshore intrusions. It is remarkable that the occurrence of T. trachurus larvae and juveniles was limited to locations over the shelf where jellyfish were observed and never offshore. This suggests that the association between fish and jellyfish occur once jellyfish have been advected from offshore towards the shelf, favouring the survival of larvae and juveniles of T. trachurus.
Paraules clau: Medusa; Engraulis encrasicolus; Trachurus trachurus; Shelf-slope front; Eddies; NW Mediterranean
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Navarro J., A. Perezgrueso, C. Barría, M. Coll
Journal of Fish Biology, 92, 5, 1657-1662. DOI: 10.1111/jfb.13609 (BibTeX: navarro.etal.2018f)
Resum: Veure
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Bellaaj-Zouari A., M. Bel Hassen, V. Balagué, E. Sehli, M.Y. Ben Kacem, F. Akrout, A. Hamza, R. Massana
Aquatic Microbial Ecology, 81, 37-53. DOI: 10.3354/ame01857 (BibTeX: bellaajzouari.etal.2018)
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Perissi I., S. Falsini, U. Bardi, D. Natalini, M. Green, A. Jones, J. Solé
Sustainability, 10, 11, Article number 4225. DOI: 10.3390/su10114225 (BibTeX: perissi.etal.2018)
Resum: Veure
The Paris Agreement, ratified in 2015, pledged to reduce greenhouse gas emissions within a Global Carbon Budget that limits the global temperature increase to less than 2º C. With the Roadmap 2050 mitigation measures, the European Union has a target to reduce emissions by 80% of their 1990 value by 2050 but without giving an estimation or a maximum ceiling for the total amount of cumulative greenhouse gases emissions over that period. Thus, the impact of the EU regulations on global warming remains unestimated. The aim and the novelty of this study are to develop a set of potential European emissions trajectories, within the Global Carbon Budget and at the same time satisfying the Roadmap 2050 goals. The result of the study highlights the urgency to reinforce mitigation measures for Europe as soon as possible because any delay in policy implementation risks the Roadmap 2050 mitigation package being insufficient to achieve the objectives of the Paris treaty.
Paraules clau: carbon budget; greenhouse gases; decarbonization; climate change
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Fernández-Álvarez F.A., A. Machordom, R. García-Jiménez, C.A. Salinas-Zavala, R. Villanueva
Scientific Reports, 8, 3440. DOI: 10.1038/s41598-018-21501-y (BibTeX: fernandezalvarez.etal.2018b)
Resum: Veure
Cephalopods are primarily active predators throughout life. Flying squids (family Ommastrephidae) represents the most widely distributed and ecologically important family of cephalopods. While the diets of adult flying squids have been extensively studied, the first feeding diet of early paralarvae remains a mystery. The morphology of this ontogenetic stage notably differs from other cephalopod paralarvae, suggesting a different feeding strategy. Here, a combination of Laser Capture Microdissection (LCM) and DNA metabarcoding of wild-collected paralarvae gut contents for eukaryotic 18S v9 and prokaryotic 16S rRNA was applied, covering almost every life domain. The gut contents were mainly composed by fungus, plants, algae and animals of marine and terrestrial origin, as well as eukaryotic and prokaryotic microorganisms commonly found in fecal pellets and particulate organic matter. This assemblage of gut contents is consistent with a diet based on detritus. The ontogenetic shift of diet from detritivore suspension feeding to active predation represents a unique life strategy among cephalopods and allows ommastrephid squids to take advantage of an almost ubiquitous and accessible food resource during their early stages. LCM was successfully applied for the first time to tiny, wild-collected marine organisms, proving its utility in combination with DNA metabarcoding for dietary studies.
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Lo Iacono C., K. Robert, R. Gonzalez-Villanueva, A. Gori, J.M. Gili, C. Orejas
Progress in Oceanography, 169, 169-180. DOI: 10.1016/j.pocean.2018.02.012 (BibTeX: loiacono.etal.2018)
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Preface (2018)
Gasol J.M., D.L. Kirchman
In: Microbial Ecology of the Ocean, Third edition, Ed. J.M. Gasol, D.L. Kirchman. XIII-XIV. ISBN: 978-1-119-10718-7 (BibTeX: gasol.kirchman.2018f)
Resum: Veure
The first edition of Microbial Ecology of the Oceans was published almost 20 years ago, and the second edition reached the bookstores nearly 10 years ago. It is about time for a third edition. This one, like the second edition, is not a revision but really a new book. In addition to having new topics, the book has subjects that had been dealt with in previous versions but have been approached from a different point of view, usually by different authors. This third edition, however, has the same audience as the other two editions: advanced undergraduates, beginning graduate students, and colleagues from other fields wishing to learn about microbes and the processes they mediate in marine systems. As we discuss in Chapter 1, aquatic microbial ecology has become a well‐established discipline that is still growing in size and attracting practitioners from other disciplines. This book is for students and colleagues looking for an updated view of some aspects of the field, written at an accessible level. Although a multi‐authored book of limited size can never be a proper textbook, the various editions of the book—combined, can be used as one—with the additional advantage that together they reflect the evolution of the field (or so we hope). This edition does not replace the two previous ones even if some subjects have advanced more than others since 2000. Although some chapters of the previous editions might now seem old, most are still useful for a basic course in marine microbial ecology or microbial oceanography. [...]
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Rotllant G., F. Palero, P.B. Mather, H.D. Bracken-Grissom, M.B. Santos
Hydrobiologia, 825, 1, 1-4. DOI: 10.1007/s10750-018-3773-y (BibTeX: rotllant.etal.2018a)
Resum: Veure
This Special Issue on Crustacean Genomics arises from the TCS 2017 conference held in Barcelona, Spain, between 19 and 22 June, 2017. Applications of next generation sequencing have expanded rapidly over recent years, unveiling many new and exciting areas of genomic research. This includes novel insights into physiology, reproductive biology, response to environmental challenges, and their evolutionary history. Despite their importance, crustaceans still lack genomic resources compared with other widely-studied groups such as insects and vertebrates. The present volume integrates a collection of contributions from the speakers, and compiles the main results presented during the symposium. Following the structure of the Crustacean Genomics workshop, contributed papers have been arranged in two main blocks, a first set of studies focused on the use of transcriptomics to investigate crustacean physiology and reproduction while the second set focused on molecular systematics and evolutionary studies.
Paraules clau: Next generation sequencing; Molecular systematics; Growth; Reproduction; Crustacea; Genomics
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Marti-Puig P., M. Serra-Serra, A. Campos-Candela, R. Reig-Bolano; A. Manjabacas, M. Palmer
Environmental Modelling & Software, 106, 68-76. DOI: 10.1016/j.envsoft.2018.01.007 (BibTeX: martipuig.etal.2018b)
Resum: Veure
Scoring animal behavior is increasingly needed for better understanding ecological processes. For example, behavior shapes harvesting likelihood, thus management of harvested resources should improve after accounting for behavior-driven processes. Automatic video-recording at controlled arenas is the most widespread method for scoring behavior. However, long term tracking animals while keeping identity is still an opened challenge. Here, we develop an ad-hoc algorithm for multi-tracking objects during days or even weeks, to fulfill the particular needs for a behavioral assay concerning a fish species targeted by recreational fishing. Specifically, we overcome the challenge of keeping fish identity in a context where they often disappeared from the camera when entering a shelter, the pixel size was low compared to the size of the arena and the lighting was constrained by the wellbeing of the fish. This work may contribute to better assess the behavioral features of fish in long-lasting lab conditions.
Paraules clau: Multi-object tracking; Tracking by identification; Long-lasting tracking; Behavioral assays
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Dall´Osto M., C. Geels, D.C.S. Beddows, D. Boertmann, R. Lange, J. K. Nøjgaard, R.M. Harrison, R. Simó, H. Skov, A. Massling
Scientific Reports, 8, 6109, 1-10. DOI: 10.1038/s41598-018-24426-8 (BibTeX: dallosto.etal.2018)
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Solé J., A. García-Olivares, A. Turiel, J. Ballabrera-Poy
Renewable Energy, 116, 258-271. DOI: 10.1016/j.renene.2017.09.035 (BibTeX: sole.etal.2018)
Resum: Veure
We use the concept of Energy Return On energy Invested (EROI) to calculate the amount of the available net energy that can be reasonably expected from World oil liquids during the next decades (till 2040). Our results indicate a decline in the available oil liquids net energy from 2015 to 2040. Such net energy evaluation is used as a starting point to discuss the feasibility of a Renewable Transition (RT). To evaluate the maximum rate of Renewable Energy Sources (RES) development for the RT, we assume that, by 2040, the RES will achieve a power of 11 TW (1012 Watt). In this case, by 2040, between 10 and 20% of net energy from liquid hydrocarbons will be required. Taking into account the oil liquids net energy decay, we calculate the minimum annual rate of RES deployment to compensate it in different scenarios. Our study shows that if we aim at keeping an increase of 3% of net energy per annum, an 8% annual rate of RES deployment is required. Such results point out the urgent necessity of a determined policy at different levels (regional, national and international) favoring the RT implementation in the next decades
Paraules clau: EROI Energy transition Renewable energy Fossil fuels Oil liquids Net energy URR (Ultimate Recoverable Resources)
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Montero Serra I.,
PhD thesis. Director/es: C. Linares Prats, J. Garrabou. Barcelona. (BibTeX: monteroserra.2018b)
Resum: Veure
Temperate benthic communities face cumulative impacts from multiple stressors acting both at local and global scales. Understanding how local management and ocean warming affect the dynamics and resilience of dominant habitat-forming species is central to marine conservation. In this thesis, we combined long-term demographic surveys and large-scale distribution datasets with innovative population and spatial modeling approaches, and meta-analyses to unravel the causes and consequences of extreme life-histories. The final goal was to understand resilience patterns and mechanisms, and to assess the effectiveness of widely used conservation tools such as fishing regulations, marine protected areas (MPAs), and active restoration. [...]
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Domínguez Carrió D.,
PhD thesis. Director/es: J.M. Gili, J.Ll. Riera. Barcelona. (BibTeX: dominguezcarrio.2018c)
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Lin W., M. Portabella
Resum: Veure
Work Package (WP) 5000 uses the knowledge acquired in previous TGSCATT WPs to consolidate, validate and document the Level-1 to Level-2 inversion algorithms for TDS-1. Validation entails the development of extended TDS-1 matchup datasets with new independent measurements to validate the performance of the inversion algorithms over a wide range of conditions. The task should result in documentation of the TDS-1 Level 2 inversion algorithms in the form of Algorithm Theoretical Basis Documents (ATBD). Over the course of the TGSCATT project, a new Level 2 SGR-ReSI wind dataset, using the so-called Calibrated Bistatic Radar Equation (CBRE) approach [1], has been made available to the team. Such wind dataset addresses several systematic and random errors present in earlier SGR-ReSI data versions and is therefore of high interest to the project. As such, WP5000 has been somewhat redefined and is now focused on the objective validation of the new wind dataset.
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Nunes S., M. Latasa, J.M. Gasol, M. Estrada
Marine Ecology Progress Series, 592, 57-75. DOI: 10.3354/meps12493 (BibTeX: nunes.etal.2018)
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Ortega-Retuerta E., C. Marrasé, A. Muñoz-Fernández, M.M. Sala, R. Simó, J.M. Gasol
Science of The Total Environment, 631-632, 180-190. DOI: 10.1016/j.scitotenv.2018.02.341 (BibTeX: ortegaretuerta.etal.2018b)
Resum: Veure
Transparent Exopolymer Particles (TEPs) are a subclass of organic particles with high impact in biogeochemical and ecological processes, such as the biological carbon pump, air-sea interactions, or the microbial loop. However, the complexity in production and consumption makes TEP dynamics hardly predictable, calling for the need of descriptive studies about the in situ dynamics of these particles. We followed monthly TEP dynamics and combined them with a dataset of environmental variables during three years in a coastal site of the oligotrophic North Western Mediterranean (Blanes Bay). TEP concentration, ranging from 11.3 to 289.1 μg XG eq L−1 (average 81.7 ± 11.7 μg XG eq L−1), showed recurrent peaks in early summer (June–July). TEP were temporally disconnected from chlorophyll a maxima, that occurred in late winter and early spring (maxima 1.21 μg L−1), but they were significantly related to the abundance of specific phytoplankton groups (diatoms and dinoflagellates) and also coincided with periods of low nutrient concentrations. The fraction of particulate organic carbon in the form of TEP (the TEP:POC and TEP:PM ratios) were also highest in early summer, indicating that TEP-enriched particles of low density accumulate in surface waters during stratified periods. We hypothesize that the accumulation of these particles affects the microbial food web by enhancing the activity of specific prokaryotic extracellular enzymes (esterase, β-glucosidase and alkaline phosphatase) and promoting the abundance of heterotrophic nanoflagellates.
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Aulicino G., Y. Cotroneo, I. Ansorge, M. van der Berg, C. Cesarano, M. Belmonte, E. Olmedo
Earth System Science Data, 10, 1227–1236. DOI: 10.5194/essd-10-1227-2018 (BibTeX: aulicino.etal.2018)
Resum: Veure
We present here sea surface salinity (SSS) and temperature (SST) data collected on board the S.A. Agulhas-I and S.A. Agulhas-II research vessels, in the framework of the South African National Antarctic Programme (SANAP). Onboard Sea-Bird thermosalinographs were regularly calibrated and continuously monitored in-between cruises, and no appreciable sensor drift emerged. Water samples were taken on a daily basis and later analyzed with a Portasal salinometer; some CTD measurements collected along the cruises were used to validate the data. No systematic differences appeared after a rigorous quality control on continuous data. Results show that salinity measurement error was a few hundredths of a unit on the practical salinity scale. Quality control included several steps, among which an automatic detection of unreliable values through selected threshold criteria and an attribution of quality flags based on multiple criteria, i.e., analysis of information included in the cruise reports, detection of insufficient flow and/or presence of air bubbles and ice crystals in the seawater pipe, visual inspection of individual campaigns, and ex post check of sea ice maps for confirming ice field locations. This data processing led us to discard about 36% of acquired observations, while reliable data showed an excellent agreement with several independent SSS products. Nevertheless, a sea ice flag has been included for identifying valid data which could have been affected by scattered sea ice contamination. In our opinion, this dataset, available through an unrestricted repository at https://doi.org/10.7289/V56M3545, contributes to improving the knowledge of surface water features in one of the most important regions for global climate. The dataset will be highly valuable for studies focusing on climate variability in the Atlantic sector of the Southern Ocean, especially across the Antarctic Circumpolar Current and its fronts. Furthermore, we expect that the collected SSS data will represent a valuable tool for the calibration and validation of recent satellite observations provided by SMOS and Aquarius missions.
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Casas D., A. Pimentel, J. Pacheco, E. Martorelli, A. Sposato, G. Ercilla, B. Alonso, F. Chiocci
Journal of Volcanology and Geothermal Research, 356, 127-140. DOI: 10.1016/j.jvolgeores.2018.02.017 (BibTeX: casas.etal.2018a)
Resum: Veure
High-resolution bathymetric data and seafloor sampling were used to characterize the most recent volcanic eruption in the Azores region, the 1998–2001 Serreta submarine eruption. The vent of the eruption is proposed to be an asymmetric topographic high, composed of two coalescing volcanic cones, underlying the location where lava balloons had been observed at the sea surface during the eruption. The volcanic products related to the 1998–2001 eruption are constrained to an area of ~0.5 km2 around the proposed vent position. A submarine Strombolian-style eruption producing basaltic lava balloons, ash and coarse scoriaceous materials with limited lateral dispersion led to the buildup of the cones. The 1998–2001 Serreta eruption shares many similarities with other intermediate-depth lava balloon-forming eruptions (e.g., the 1891 eruption offshore Pantelleria and the 2011–2012 eruption south of El Hierro), revealing the particular conditions needed for the production of this unusual and scarcely documented volcanic product.
Paraules clau: Submarine volcanism; Lava balloons; Multibeam bathymetry; Terceira; Serreta Ridge; Cone formation
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Olmedo E., C. Gabarró, V. González-Gambau, J. Martínez, J. Ballabrera-Poy, A. Turiel, M. Portabella, S. Fournier, T. Lee
Remote Sensing, 10, 11, 1772. DOI: 10.3390/rs10111772 (BibTeX: olmedo.etal.2018a)
Resum: Veure
This paper aims to present and assess the quality of seven years (2011–2017) of 25 km nine-day Soil Moisture and Ocean Salinity (SMOS) Sea Surface Salinity (SSS) objectively analyzed maps in the Arctic and sub-Arctic oceans (50ºN–90ºN). The SMOS SSS maps presented in this work are an improved version of the preliminary three-year dataset generated and freely distributed by the Barcelona Expert Center. In this new version, a time-dependent bias correction has been applied to mitigate the seasonal bias that affected the previous SSS maps. An extensive database of in situ data (Argo floats and thermosalinograph measurements) has been used for assessing the accuracy of this product. The standard deviation of the difference between the new SMOS SSS maps and Argo SSS ranges from 0.25 and 0.35. The major features of the inter-annual SSS variations observed by the thermosalinographs are also captured by the SMOS SSS maps. However, the validation in some regions of the Arctic Ocean has not been feasible because of the lack of in situ data. In those regions, qualitative comparisons with SSS provided by models and the remotely sensed SSS provided by Aquarius and SMAP have been performed. Despite the differences between SMOS and SMAP, both datasets show consistent SSS variations with respect to the model and the river discharge in situ data, but present a larger dynamic range than that of the model. This result suggests that, in those regions, the use of the remotely sensed SSS may help to improve the models.
Paraules clau: sea surface salinity; remote sensing; Arctic ocean; SMOS; Arctic rivers; data processing; quality assessment
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Seeleuthner Y., S. Mondy, V. Lombard, Q. Carradec, E. Pelletier, M. Wessner, J. Leconte, J.F. Mangot, J. Poulain, K. Labadie, R. Logares, S. Sunagawa, V. de Berardinis, M. Salanoubat, C. Dimier, S. Kandels-Lewis, M. Picheral, S. Searson, S. Pesant, N. Poulton, R. Stepanauskas, P. Bork, C. Bowler, P. Hingamp, M.B. Sullivan, D. Iudicone, R. Massana, J.M. Aury, B. Henrissat, E. Karsenti, O. Jaillon, M. Sieracki, C. de Vargas, P. Wincker
Nature Communications, 9, 310, DOI: 10.1038/s41467-017-02235-3 (BibTeX: seeleuthner.etal.2018)
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Hoareau N., A. Turiel, M. Portabella, J. Ballabrera-Poy, J. Vogelzang
IEEE Transactions on Geoscience and Remote Sensing, 56, 9, 5525-5536. DOI: doi.org/10.1109/TGRS.2018.2819240 (BibTeX: hoareau.etal.2018a)
Resum: Veure
The Soil Moisture and Ocean Salinity (SMOS) and Aquarius satellite missions have produced the first sea-surface salinity (SSS) maps from space. The quality of the retrieved SSS must be assessed, in terms of its validation against sparse ground truth, but also in terms of its ability to detect and characterize geophysical processes, such as mesoscale features. Such characterization is sometimes elusive due to the presence of noise and processing artifacts that continue to affect stateof- the-art remote sensing SSS maps. A new method, based on singularity analysis, is proposed to contribute to the assessment of the geophysical characteristics of such maps. Singularity analysis can be used to directly assess the spatial consistency of the SSS fields and to improve the estimation of the wavenumber spectra slope through a new method, the singularity power spectra (SPS). To demonstrate the SPS performance and utility, we applied SPS to different gridded SSS maps, such as SMOS and Aquarius high-level products, the output of a numerical simulation, in situ reanalysis, and climatology, as well as to other sea-surface temperature products for reference. The singularity analysis and SPS methods reveal that both the SMOS level 4 and the Aquarius combined active passive products are both able to describe the geometry of the existing geophysical structures and provide consistent spectral slopes. This paper demonstrates that beyond the remaining sources of uncertainty in remote sensing SSS products, valuable dynamical information on the ocean state can be extracted from these SSS products.
Paraules clau: Aquarius, geophysical consistence, remote sensing, sea-surface salinity (SSS), singularity analysis, singularity power spectra (SPS), Soil Moisture and Ocean Salinity (SMOS).
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Mestre M., C. Ruiz-González, R. Logares, C.M. Duarte, J.M. Gasol, M.M. Sala
Proceedings of the National Academy of Sciences of the United States of America, 115, 29, 6799-6807. DOI: 10.1073/pnas.1802470115 (BibTeX: mestre.etal.2018a)
Resum: Veure
The sinking of organic particles formed in the photic layer is a main vector of carbon export into the deep ocean. Although sinking particles are heavily colonized by microbes, so far it has not been explored whether this process plays a role in transferring prokaryotic diversity from surface to deep oceanic layers. Using Illumina sequencing of the 16S rRNA gene, we explore here the vertical connectivity of the ocean microbiome by characterizing marine prokaryotic communities associated with five different size fractions and examining their compositional variability from surface down to 4,000 m across eight stations sampled in the Atlantic, Pacific, and Indian Oceans during the Malaspina 2010 Expedition. Our results show that the most abundant prokaryotes in the deep ocean are also present in surface waters. This vertical community connectivity seems to occur predominantly through the largest particles because communities in the largest size fractions showed the highest taxonomic similarity throughout the water column, whereas free-living communities were more isolated vertically. Our results further suggest that particle colonization processes occurring in surface waters determine to some extent the composition and biogeography of bathypelagic communities. Overall, we postulate that sinking particles function as vectors that inoculate viable particle-attached surface microbes into the deep-sea realm, determining to a considerable extent the structure, functioning, and biogeography of deep ocean communities
Paraules clau: Particle sinking; Deep ocean; Marine prokaryotic metacommunities; Dispersion; Connectivity
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Santín A., J. Grinyó, M.J. Uriz, A. Gori, C. Dominguez-Carrió, J.M. Gili
Deep-Sea Research. Part I: Oceanographic Research Papers, 131, 75-86. DOI: 10.1016/j.dsr.2017.11.003 (BibTeX: santin.etal.2018b)
Resum: Veure
Sponge assemblages on continental shelves and slopes around the world have been known about for centuries. However, due to limitations of the traditional sampling systems, data about individual sponge species rather than assemblages have been reported. This study characterizes sponge assemblages over a wide bathymetric range (~50–350 m depth) and covering the entire continental shelf and the upper slope of the Menorca Channel, an area soon to be declared a Marine Protected Area (MPA) as part of the Natura 2000 Network. Quantitative analysis of 85 video-transects (a total linear distance of 75 km), together with representative collections to confirm species identifications, allowed us to discriminate six major assemblages. Differences in the assemblages mainly corresponded to differences in substrate type and depth. On the inner continental shelf, a semi-sciaphilous Axinellid assemblage dominated the rocky outcrops. Maërl beds on the inner continental shelf were dominated by Haliclona (Reniera) mediterranea, whereas the horny sponge Aplysina cavernicola and several other haliclonids mostly dominated maërl beds and rocky substrates of the outer shelf. Soft sediments on the shelf break hosted a monospecific Thenea muricata assemblage, whereas rocky substrates of the shelf break were characterized by a mixture of encrusting, columnar and fan-shaped sponges. Finally, the upper slope was dominated by Hamacantha (Vomerula) falcula and the hexactinellid Tretodictyum reiswigi. Overall, sponge diversity showed its highest values above the shelf break, plummeting severely on the upper slope. Despite this diversity decrease, we found very high densities (> 70 ind./m2) of sponges over vast areas of both the shelf break and the upper slope.
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Young J.R., P.R. Bown, L. Cros, K. Hagino, R.W. Jordan
Journal of Nannoplankton Research, 38, 1, (BibTeX: young.etal.2018a)
Resum: Veure
Here we show that the extant coccolithophore Syracosphaera corolla Lecal, 1966 comprises two con-sistently different non-intergrading morphotypes characterised respectively by exothecal coccoliths with wide and narrow central-areas. These are interpreted as separate species and so a new species is described, S. azureaplaneta, and a revised description is given for S. corolla.
Paraules clau: Coccolithophores; Syracosphaera; Extent
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Tomlinson B., F. Maynou, A. Sabatés, V. Fuentes, A. Canepa, S. Sastre
Estuarine, Coastal and Shelf Science, 201, 198-207. DOI: 10.1016/j.ecss.2015.11.012 (BibTeX: tomlinson.etal.2018a)
Resum: Veure
Despite the large fluctuation in annual recordings of gelatinous plankton along the Catalan coast in the north western Mediterranean and the lack of long term data sets, there is a general perception that jellyfish abundances are increasing. Local authorities are concerned about the stranding events and arrivals of jellyfish to beaches and believe it could reduce the recreational appeal of the beaches – a valuable ecosystem service for the regional tourist industry. Previous studies also demonstrate the predation of jellyfish (Pelagia noctiluca ephyrae) upon some small pelagic fish larvae (Engraulis encrasicolus). Small pelagics are the principal source of revenue for the local fisheries. A social-ecological model was created in order to capture the effects of changes in abundance of P. noctiluca upon the local fisheries, the tourist industry and the wider economy. The following sub-models were constructed and connected following the systems approach framework methodology: an age-class based fisheries model; a jellyfish population matrix model; a jellyfish stranding model; a study on the impact of jellyfish strandings on beach users; and an economic input–output matrix. Various future scenarios for different abundances of jellyfish blooms were run. The “Expected blooms” scenario is similar to the quantity and size of blooms for 2000–2010. For a hypothetical “No blooms” scenario (standard background level of jellyfish but without any blooms) landings would increase by around 294 tonnes (5.1%) per year (averaged over 10 years) or approximately 0.19 M€ in profits per year (4.5%), and strandings would decrease by 49%. In a “Frequent blooms” scenario, landings would decrease by around 147 tonnes per year (2.5%) and decrease profits by 0.10 M€ per year (2.3%), and strandings would increase by 32%. Given the changes that these scenarios would cause on the regional gross domestic product and employment, this study concludes that the overall impact of either of these scenarios on the economy would not be significant at the regional scale.
Paraules clau: Pelagia noctiluca, anchovy, sardine, small pelagic fisheries, social-ecosystem model, jellyfish strandings, Mediterranean, Spain, Catalonia
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Estrada F., J. Galindo‐Zaldívar, J.T. Vázquez, G. Ercilla, E. D\'Acremont, B. Alonso, C. Gorini
Terra nova, 30, 1, 24-33. DOI: 10.1111/ter.12304 (BibTeX: estrada.etal.2018a)
Resum: Veure
The Alboran Sea constitutes a Neogene-Quaternary basin of the Betic-Rif Cordillera, which has been deformed since the Late Miocene during the collision between the Eurasian and African plates in the westernmost Mediterranean. NNE-SSW sinistral and WNW-ESE dextral conjugate fault sets forming a 75° angle surround a rigid basement spur of the African plate, and are the origin of most of the shallow seismicity of the central Alboran Sea. Northward, the faults decrease their transcurrent slip, becoming normal close to the tip point, while NNW-SSE normal and sparse ENE-WSW reverse to transcurrent faults are developed. The uplifting of the Alboran Ridge ENE-WSW antiform above a detachment level was favoured by the crustal layering. Despite the recent anticlockwise rotation of the Eurasian-African convergence trend in the westernmost Mediterranean, these recent deformations -consistent with indenter tectonics characterised by a N164°E trend of maximum compression- entail the highest seismic hazard of the Alboran Sea.
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Brackenridge R.E., D.A.V. Stow, F.J. Hernández‐Molina, C. Jones, A. Mena, I. Alejo, E. Ducassou, E. Llave, G. Ercilla, M.A. Nombela
Sedimentology, 65, 7, 2223-2252. DOI: 10.1111/sed.12463 (BibTeX: brackenridge.etal.2018a)
Resum: Veure
This work presents a detailed study of CONTOURIBER and Integrated Ocean Drilling Program 339 sediment data targeting sand‐rich contourites in the Eastern Gulf of Cadiz. All of the collected sediments are interpreted as contourites (deposited or reworked by bottom currents) on the basis of oceanographic setting, seismic and morphometric features, and facies characteristics. A variety of sandy and associated facies are found across the study area including: (i) bioturbated muddy contourites; (ii) mottled silty contourites; (iii) very fine mottled and fine‐grained bioturbated sandy contourites; (iv) massive and laminated sandy contourites; and (v) coarse sandy/gravel contourites. The thickest sands occur within contourite channels and there is a marked reduction in sand content laterally away from channels. Complementary to the facies descriptions, grain‐size analysis of 675 samples reveals distinctive trends in textural properties linked to depositional processes under the action of bottom currents. The finest muddy contourites (<20 μm) show normal grain‐size distributions, poor to very poor sorting, and zero or low skewness. These are deposited by settling from weak bottom currents with a fine suspension load. Muddy to fine sandy contourites (20 to 200 μm) trend towards better sorting and initially finer and then coarser skew. These are typical depositional trends for contourites. As current velocity and carrying capacity increase, more of the finest fraction remains in suspension and bedload transport becomes more important. Clean sandy contourites (>200 μm) are better sorted. They result from the action of dominant bedload transport and winnowing at high current speeds. The results highlight the importance of bottom current velocity, sediment supply and bioturbational mixing in controlling contourite facies. Despite growing interest in their hydrocarbon exploration potential, contourite sands have remained poorly understood. This research therefore has important implications for developing current understanding of these deposits and aiding the correct interpretation of deep marine sands and depositional processes.
Paraules clau: Contourites; Deep-water sands; Grain size; Gulf of Cadiz; Sediment facies model
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Santis W., L. Aimola, E.J.D. Campos, P. Castellanos
Dynamics of Atmospheres and Oceans, 81, 30-41. DOI: 10.1016/j.dynatmoce.2017.11.004 (BibTeX: santis.etal.2018)
Resum: Veure
The interdecadal variability of the atmospheric and oceanic meridional overturning circulation is studied, using a coupled model with two narrow meridional barriers representing the land and a flat bottomed Aquaplanet. Empirical orthogonal function (EOF) analysis are usedin the atmospheric and oceanic meridional overturning cells, revealing the atmospheric interdecadal variability is dominated by an annular mode, in both hemispheres, whichintroduces in the ocean a set of patterns of variability. The most energetic EOFs in the oceanare the barotropic responses from the annular mode. The interaction between the heat anomalies, due to the barotropic response, and the thermohaline circulation of each basinleads to a resonance mechanism that feeds back to the atmospheric forcing, modulatingthe annular mode spectrum. Besides the barotropic response, the annular mode introduces anomalies of salinity and temperature in the subtropical Atlantic that affects its upper buoy-ancy. These anomalies are incorporated within the ocean circulation and advected until theareas of deep sinking in the northern Atlantic, impacting on its overturning circulation as well
Paraules clau: AMOC Annular mode Idealized experiments
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Santis W., L. Aímola, P. Castellanos, E.J.D. Campos
International Journal of Climatology, 38, S1, e985-e997. DOI: 10.1002/joc.5424 (BibTeX: santis.etal.2018d)
Resum: Veure
The role that the Indonesian Throughflow plays on climate is investigated in an alternative scenario, expected during glacial ages. The equatorwards shift of the Southern Hemisphere westerlies found in glacial ages acts to decrease the Agulhas Leakage (AL) and the thermohaline circulation (THC) in the Atlantic. Recent results suggest that these changes are followed by an increased THC in the Pacific, through an inter-basin seesaw mechanism. The enhanced circulation in the Pacific demands thermocline water to cross the equator towards northern latitudes, which shifts the water source of the throughflow from the low-salinity North Pacific to the relative saltier South Pacific. It is shown that in this equilibrium, the salinity anomalies of the throughflow impact the inter-basin seesaw towards the restoration of the modern climate, enhancing the North Atlantic Deep Water (NADW) formation and decreasing the THC in the Pacific. These results are consistent with paleo-observations and provide new insights to interpreting the climate changes in glacial periods.
Paraules clau: Indonesian Throughflow; inter-basin seesaw effect; meridional overturning circulation; idealized experiments
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Fernández-Álvarez F.Á., R. Villanueva, H.-J.T. Hoving, W.F. Gilly
Reviews in Fish biology and Fisheries, 28, 1, 191-199. DOI: 10.1007/s11160-017-9498-6 (BibTeX: fernandezalvarez.etal.2018c)
Resum: Veure
Sperm storage is common in internally fertilizing animals, but is also present in several external fertilizers, such as many cephalopods. Cephalopod males attach sperm packets (spermatangia) to female conspecifics during mating. Females of eight externally fertilizing families comprising 25% of cephalopod biodiversity have sperm-storage organs (seminal receptacles) in their buccal area, which are not in direct physical contact with the deposited spermatangia. The mechanism of sperm transmission between the implantation site and the storage organ has remained a major mystery in cephalopod reproductive biology. Here, jumbo squid females covering almost the entire life cycle, from immature to a laboratory spawned female, were used to describe the internal structure of the seminal receptacles and the process of sperm storage. Seminal fluid was present between the spermatangia and seminal receptacles, but absent in regions devoid of seminal receptacles. The sperm cellular component was formed by spermatozoa and round cells. Although spermatozoa were tracked over the buccal membrane of the females to the inner chambers of the seminal receptacles, round cells were not found inside the seminal receptacles, suggesting that spermatozoa are not sucked up by the muscular action of the seminal receptacles. This finding supports the hypothesis that spermatozoa are able to actively migrate over the female skin. Although further experimental support is needed to fully confirm this hypothesis, our findings shed light on the elusive process of sperm storage in many cephalopods, a process that is fundamental for understanding sexual selection in the sea.
Paraules clau: Dosidicus gigas, Reproduction, Sexual selection, Sperm storage organs, Spermatangium, Squid
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9.9 Mb
Gasser Rubinat M.,
PhD thesis. Director/es: J.L. Pelegrí. (BibTeX: gasserrubinat.2018b)
Resum: Veure
The Mediterranean Outflow Water (MOW) is a dense (¿>1028.5 kg/m3), saline (38.5 g/kg) ocean stream originated in the evaporative Mediterranean basin flowing westward past Espartel Sill as a fast (>1 m/s) and often unstable (as indicated by its gradient Richardson number) gravity current. During its descense into the Gulf of Cadiz, the MOW entrains the overlying North Atlantic Central Water (NACW), until the density difference between both water masses vanishes, and reaches its equilibrium depth. Inertia, Coriolis and frictional forces (both internal and with the bottom), as well as pressure gradients (associated with both seafloor slope and density gradients), play varying roles throughout the MOW’s trajectory. In particular, bathymetric steering due to contouritic, turbiditic and diapiric structures controls the early trajectory of the outflow. Using both historic and current hydrographic data, and a new high-resolution bathymetry of a critical region west of Espartel Sill, we examine the hydrographic characteristics of the MOW and the mechanisms that set its pathway. Our study is complemented with the proposal of simple models that help explain pbservations of vertical mixing in the Strait of Gibraltar and the behavior of the MOW as a gravity current within the Gulf of Cádiz, as well as with a new tool, based on water tributaries methods, that assesses the relative impact of both seafloor slope and Coriolis force in steering the outflow.
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691.1 Kb
Simó R., V. Saló, R. Almeda, J. Movilla, I. Trepat, E. Saiz, A. Calbet
Biogeochemistry, 141, 2, 125-142. DOI: 10.1007/s10533-018-0506-2 (BibTeX: simo.etal.2018b)
Resum: Veure
The ubiquitous, biogenic trace gas dimethylsulfide (DMS) represents the largest natural source of atmospheric sulfur. Given DMS involvement in cloud formation and climate, understanding and parameterizing the oceanic DMS source and cycling processes is a necessary challenge. We report DMS cycling rates from microzooplankton dilution grazing experiments conducted monthly during 1 year in coastal northwestern Mediterranean waters. Concentrations of DMS, its algal precursor dimethylsulfoniopropionate (DMSPt) and chlorophyll a (Chla) ranged 0.9–11 nmol L−1, 10–71 nmol L−1, and 0.2–1.5 µg L−1, respectively. By comparing the growth and stock production rates of the DMSP-producing algae to those of total phytoplankton, we estimated that 3 ± 4% (range 0.4–12%) of the carbon primary production was invested in DMSP biosynthesis. Microzooplankton grazing rates on DMSP-producing phytoplankton (0.46–1.45 day−1) were generally higher than those on the bulk assemblage (0.08–0.99 day−1), except in midsummer months. This could have been due to the smaller size of most DMSP producers. There was no indication of micrograzer selection against DMSP-containing phytoplankton, since they were not grazed at lower rates than the bulk phytoplankton assemblage. A proportion of 6–20% of the grazed DMSP was converted into DMS, and this grazing-derived production accounted for 32–96% of dark gross DMS production by the total community. Bacteria consumed daily ≤ 14–100% of the gross DMS production, which resulted in biological DMS turnover times of 1 to ≥ 10 days. Throughout the year, grazing-mediated DMS production explained 73% of the variance in the DMS concentration, implying that microzooplankton grazing plays a major role in controlling DMS concentration in surface waters across a broad range of environmental and productivity conditions in the Mediterranean Sea. These findings should help improve the representation of herbivore grazing in prognostic models to predict the distribution and dynamics of the global DMS emission and its feedback response to changing climate
Paraules clau: Dimethylsulfide; Dimethylsulfoniopropionate; Microzooplankton; Grazing; Dilution experiments; Mediterranean
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Shin Y.-J., J.E. Houle, E. Akoglu, J.L. Blanchard, A. Bundy, M. Coll, H. Demarcq, C. Fu, E.A. Fulton, J.J. Heymans, B. Salihoglu, L. Shannon, M. Sporcic, L. Velez
Ecological Indicators, 89, 317-326. DOI: 10.1016/j.ecolind.2018.01.010 (BibTeX: shin.etal.2018a)
Resum: Veure
Ecological indicators are widely used to characterise ecosystem health. In the marine environment, indicators have been developed to assess the ecosystem effects of fishing to support an ecosystem approach to fisheries. However, very little work on the performance and robustness of ecological indicators has been carried out. An important aspect of robustness is that indicators should respond specifically to changes in the pressures they are designed to detect (e.g. fishing) rather than changes in other drivers (e.g. environment). We adopted a multi-model approach to compare and test the specificity of commonly used ecological indicators to capture fishing effects in the presence of environmental change and under different fishing strategies. We tested specificity in the presence of two types of environmental change: “random”, representing interannual climate variability and “directional”, representing climate change. We used phytoplankton biomass as a proxy of the environmental conditions, as this driver was comparable across all ecosystem models, then applied a signal-to-noise ratio analysis to test the specificity of indicators with random environmental change. For directional change, we used mean gradients to apportion the quantity of change in the indicators due to fishing and the environment. We found that depending on the fishing strategy and environmental change, ecological indicators could range from high to low specificity to fishing. As expected, the specificity of indicators to fishing almost always decreased as environmental variability increased. In 55–76% of the scenarios run with directional change in phytoplankton biomass across fishing strategies and ecosystem models, indicators were significantly more responsive to changes in fishing than to changes in phytoplankton biomass. This important result makes the tested ecological indicators good candidates to support fisheries management in a changing environment. Among the indicators, the catch over biomass ratio was most often the most specific indicator to fishing, whereas mean length was most often the most sensitive to change in phytoplankton biomass. However, the responses of indicators were highly variable depending on the ecosystem and fishing strategy under consideration. We therefore recommend that indicators should be tested in the particular ecosystem before they are used for monitoring and management purposes.
Paraules clau: Ecosystem approach to fisheries, Indicator performance, Marine ecosystem models, Scenarios, Multi-model evaluation, Signal-to-noise ratio
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Solé M., G. Rivera-Ingraham, R. Freitas
Comparative Biochemistry and Physiology. Part C, 212, 18-24. DOI: 10.1016/j.cbpc.2018.06.002 (BibTeX: sole.etal.2018b)
Resum: Veure
Bivalves are worldwide sentinels of anthropogenic pollution. The inclusion of biomarker responses in chemical monitoring is a recommended practise that has to overcome some difficulties. One of them is the time frame between sample collection and sample processing in order to ensure the preservation of enzymatic activities. In the present study, three bivalve species of commercial interest (mussel, Mytilus galloprovincialis, razor shell, Solen marginatus, and cockle, Cerastoderma edule) were processed within <2 h after being retrieved from their natural habitat, and 24 h after being transported in air under cold conditions (6–8 °C) to laboratory facilities. The enzymatic activities were compared in the three species submitted to both conditions revealing no differences in terms of carboxylesterase dependent activities (CEs) using different substrates: p-nitrophenyl acetate (pNPA), p-nitrophenyl butyrate (pNPB), 1-naphthyl acetate (1-NA), 1-naphthyl butyrate (1-NB) and 2-naphthyl acetate (2-NA). In mussels, three tissues were selected (haemolymph, gills and digestive gland). For comparative purposes, in razor shell and cockle only digestive gland was considered as it is the main metabolic organ. Baseline enzymatic activities for CEs were characterised in the digestive gland of the three bivalves using four out of the five selected CE substrates as well as the kinetic parameters (Vmax and Km) and catalytic efficiency. The in vitro sensitivity to the organophosphorus metabolite chlorpyrifos oxon was also calculated. IC50 values (pM-nM range) were lower than those obtained for vertebrate groups which suggest that bivalves have high protection efficiency against this pesticide as well as species dependent particularities.
Paraules clau: Pollution monitoring biomarkers; Carboxylesterases; Organophosphorus pesticides; Cold transport; Mussel; Razor shell; Cockle
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Rotllant G., T.V. Nguyen, J. Aizen, S. Suwansa, T. Ventura
Hydrobiologia, 825, 1, 91-119. DOI: 10.1007/s10750-017-3497-4 (BibTeX: rotllant.etal.2018c)
Resum: Veure
Over many decades there were numerous attempts to isolate gonad-stimulating factors (GSF) in crustaceans. Before omic technologies, the main neuroendocrine factors identified as ovarian development regulators in crustaceans were inhibitory in nature, belonging to the CHH family of neuropeptides produced in the eyestalk. Eyestalk ablation thus leads to ovarian development and this technique is still used in shrimp farms to induce maturation although some biological issues arise. In this manuscript, we review the current knowledge on potential GSF with emphasis on several key candidates and discuss how novel sequencing technologies might aid in better understanding the nature of the ovarian development in crustaceans. However, the gap between the rapid pace at which sequence databases are produced and mined and the experimental work that lags behind do not yet allow us to know the nature of the GSF in crustaceans. Three possible reasons are suggested: (1) crustaceans represent a very large and diverse group, then different species could have GSF of different compounds; (2) it is possible that crustaceans employ multiple hormonal factors to control vitellogenesis; (3) crustaceans might not need a GSF. Reproduction is only negatively regulated by CHH family peptides.
Paraules clau: Ovarian maturation; Gonadotropin-releasing hormone (GnRH); Crustacean hyperglycemic hormone (CHH); Pigment-dispersing hormones (PDH); Corazonin; Glycoprotein hormones (GP)
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Isla E., E. Pérez-Albaladejo, C. Porte
Scientific Reports, 8, 9154. DOI: 10.1038/s41598-018-27375-4 (BibTeX: isla.etal.2018a)
Resum: Veure
Industrial activity generates harmful substances which can travel via aerial or water currents thousands of kilometers away from the place they were used impacting the local biota where they deposit. The presence of harmful anthropogenic substances in the Antarctic is particularly surprising and striking due to its remoteness and the apparent geophysical isolation developed with the flows of the Antarctic Circumpolar current and the ring of westerly winds surrounding the continent. However, long-range atmospheric transport (LRAT) of pollutants has been detected in the Antarctic since the 70’s along the Antarctic trophic food web from phytoplankton to birds. Still, no information exists on the presence of cytotoxic compounds in marine sediments neither at basin scales (thousands of kilometers) nor in water depths (hundreds of meters) beyond shallow coastal areas near research stations. Our results showed for the first time that there is cytotoxic activity in marine sediment extracts from water depths >1000 m and along thousands of kilometers of Antarctic continental shelf, in some cases comparable to that observed in Mediterranean areas. Ongoing anthropogenic pressure appears as a serious threat to the sessile benthic communities, which have evolved in near isolation for millions of years in these environments.
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Lambertucci S.A., J. Navarro, J.A. Sanchez Zapata, K.A. Hobson, P.A.E. Alarcón, G. Wiemeyer, G. Blanco, F. Hiraldo, J.A. Donázar
Proceedings of the Royal Society. Biological Sciences, 285, 20180550. DOI: 10.1098/rspb.2018.0550 (BibTeX: lambertucci.etal.2018a)
Resum: Veure
Over the last century, marine mammals have been dramatically reduced in the world\'s oceans. We examined evidence that this change caused dietary and foraging pattern shifts of the Andean condor (Vultur gryphus) in Patagonia. We hypothesized that, after the decrease in marine mammals and the increase in human use of coastlines, condor diet changed to a more terrestrial diet, which in turn influenced their foraging patterns. We evaluated the diet by means of stable isotope analysis (δ13C, δ15N and δ34S) of current (last decade) and historical (1841–1933) feathers. We further evaluated the movement patterns of 23 condors using satellite tracking of individuals. Condors reduced their use of marine-derived prey in recent compared with historical times from 33 ± 13% to less than 8 ± 3% respectively; however, they still breed close to the coast. The average distance between the coast and nests was 62.5 km, but some nests were located close to the sea (less than 5 km). Therefore, some birds must travel up to 86 km from nesting sites, crossing over the mountain range to find food. The worldwide reduction in marine mammal carcasses, especially whales, may have major consequences on the foraging ecology of scavengers, as well as on the flux of marine inputs within terrestrial ecosystems.
Paraules clau: animal movement; condor; diet; marine sources; scavenger; stable isotopes
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de Juan S., J. Hewitt, M.D. Subida, S. Thrush
Journal of Environmental Management, 228, 319-327. DOI: 10.1016/j.jenvman.2018.09.034 (BibTeX: dejuan.etal.2018c)
Resum: Veure
It is crucial that societies are informed on the risks of impoverished ecosystem health for their well-being. For this purpose, Ecological Integrity (EI) is a useful concept that seeks to capture the complex nature of ecosystems and their interaction with social welfare. But the challenge remains to measure EI and translate scientific terminology into operational language to inform society. We propose an approach that simplifies marine ecosystem complexity by applying scientific knowledge to identify which components reflect the state or state change of ecosystems. It follows a bottom-up structure that identifies, based on expert knowledge, biological components related with past and present changing conditions. It is structured in 5 stages that interact in an adaptive way: stage 1, in situ observations suggest changes could be happening; stage 2 explores available data that represent EI; stage 3, experts\' workshops target the identification of the minimum set of variables needed to define EI, or the risk of losing EI; an optative stage 4, where deviance from EI, or risk of deviance, is statistically assessed; stage 5, findings are communicated to society. We demonstrate the framework effectiveness in three case studies, including a data poor situation, an area where lack of reference sites hampers the identification of historical changes, and an area where diffuse sources of stress make it difficult to identify simple relationships with of ecological responses. The future challenge is to operationalise the approach and trigger desirable society actions to strengthen a social-nature link.
Paraules clau: DPSIR; Ecosystem health; Ecological indicators; Socio-ecological systems; Environmental assessment
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García-Olivares A., J. Solé, O. Osychenko
Energy Conversion and Management, 158, 266-285. DOI: 10.1016/j.enconman.2017.12.053 (BibTeX: garciaolivares.etal.2018)
Resum: Veure
A 100% renewable economy would give a lasting solution to the challenges raised by climate change, energy security, sustainability, and pollution. The conversion of the present transport system appears to be one of the most difficult aspects of such renewable transition. This study reviews the technologies and systems that are being proposed or proven as alternative to fossil-fuel based transportation, and their prospects for their entry into the post-carbon era, from both technological and energetic viewpoints. The energetic cost of the transition from the current transportation system into global 100% renewable transportation is estimated, as well as the electrical energy required for the operation of the new renewable transportation sector. A 100% renewable transport providing the same service as global transport in 2014 would demand about 18% less energy. The main reduction is expected in road transport (69%), but the shipping and air sectors would notably increase their consumptions: 163% and 149%, respectively. The analysis concludes that a 100% renewable transportation is feasible, but not necessarily compatible with indefinite increase of resources consumption. The major material and energy limitations and obstacles of each transport sector for this transition are shown.
Paraules clau: 100% renewable system Transportation Transition cost Embedded energy
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Barría C., J. Navarro, M. Coll
Estuarine, Coastal and Shelf Science, 207, 383-390. DOI: 10.1016/j.ecss.2017.08.021 (BibTeX: barria.etal.2018k)
Resum: Veure
Studying the feeding ecology of an organism is essential to understanding its ecological role in the ecosystem. Although the small-spotted catshark (Scyliorhinus canicula) is widely studied, most feeding studies have been conducted using invasive techniques, such as the analysis of stomach contents. Moreover, information from the Mediterranean Sea is surprisingly scarce and not up to date. Here, we studied the feeding ecology of the small-spotted catshark in the northwestern Mediterranean Sea using stable isotopes (nitrogen and carbon isotopic values) from blood samples, with individuals released alive in the area of capture after sampling. In overall for the population of small-spotted catshark, the isotopic values were −19.01 ± 1.12‰ and 8.03 ± 0.61‰ for δ13C and for δ15N, respectively. Results reveal a diet mainly composed of euphausiids, with sex and size variations. Results confirm the ecological role of the small-spotted catshark as a mesopredator, which holds a trophic position similar to skates and rays in the study area, but lower than the other demersal and pelagic sharks analysed. The trophic behaviour of the small-spotted catshark indicates its high trophic plasticity, which could allow this species to thrive in highly exploited environments. Our methodological approach, which did not damage the target species, presents new possibilities for conducting ecological studies with other elasmobranchs in the Mediterranean Sea, a highly exploited area that hosts many threatened and rare species.
Paraules clau: Blood sampling, Demersal organisms, Isotopic mixing models, Marine predators, Sharks, Trophic ecology, Trophic level, Stable isotopes
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Tilves U., V.L. Fuentes, G. Milisenda, C.C. Parrish, S. Vizzini, A. Sabatés
Marine Ecology Progress Series, 591, 101-116. DOI: 10.3354/meps12332 (BibTeX: tilves.etal.2018a)
Resum: Veure
Jellyfish have the potential to dominate the pelagic biomass of marine ecosystems, thereby negatively affecting pelagic fish. We investigated the trophic interactions of Pelagia noctiluca (medusae and ephyrae), one of the most abundant and conspicuous jellyfish on the Catalan coast in the NW Mediterranean. A combination of stable isotope and fatty acid analyses was used to obtain a broad picture of the feeding habits of this jellyfish in order to understand its potential interactions with the most abundant fish species (larvae and adults) during the summer in the area. The results suggested that in addition to predation on fish larvae by P. noctiluca, this jellyfish had similar feeding requirements to those of most fish larvae, suggesting potential competition. The trophic niche of medusae and ephyrae overlapped highly with that of larval Engraulis encrasicolus, Trachurus mediterraneus and Sardinella aurita and to a lesser extent with that of Serranus hepatus, Sparus pagrus and Mullus barbatus. No overlap was observed with Arnoglossus sp. larvae and adult E. encrasicolus, Sardina pilchardus, T. mediterraneus and S. aurita. Our findings demonstrated that P. noctiluca could be an important predator and competitor for fish larvae, but not for adult fish. Moreover, salps were found to be a significant food source for P. noctiluca. This study provides information that should be considered in near-future ecosystem-based fishery management in regions where P. noctiluca thrives.
Paraules clau: Medusae, Ephyrae, Predation, Competition, Fish larvae, Pelagic fish
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3.5 Mb
Viúdez A.,
Journal of Geophysical Research: Oceans, 123, 5, 3705-3722. DOI: 10.1029/2017JC013735 (BibTeX: viudez.2018a)
Resum: Veure
Two fundamental modes of vertical velocity (w) in mesoscale subsurface eddies are described using the quasigeostrophic (QG) approximation and nonhydrostatic numerical modeling. The first mode of w (the spheroidal mode) arises when a spheroidal upright subsurface eddy acquires horizontal eccentricity and becomes an ellipsoid, still upright, vertically symmetric vortex. In this case, the vertical displacement of isopycnals vanishes at the middepth z50. Conservation of potential vorticity anomaly (PVA) on elliptical concave/convex isopycnals entails a three-dimensional octupolar pattern of w which also vanishes at z50. The second mode of w (the tilted mode) arises when the eddy remains spheroidal but its vertical axis tilts relative to the vertical direction. In this case, the displacement of isopycnals is largest at the middepth z50 and has a dipolar distribution. The associated w is largest at the middepth and develops also a dipolar pattern. In both spheroidal and tilted modes, the vertical velocity pattern may be inferred from the fast advection of PVA conserving fluid particles on slower translating concave/convex or tilted isopycnals. This implies that the vertical velocity of both modes is approximately QG and may be correctly inferred from the QG omega equation as long as the Rossby number remains small. Under more general circumstances, the vortex is both spheroidal and tilted. In this case, both spheroidal and tilted modes coexist but remain, to a large extent, uncoupled, rotating with different and, at least at a first order of approximation, constant phase speeds.
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García Raso J.E., J.A. Cuesta, P. Abelló, E. Macpherson
Scientia Marina, 82, 4, 207-229. DOI: 10.3989/scimar.04831.04A (BibTeX: garciaraso.etal.2018a)
Resum: Veure
An annotated checklist of the marine decapod crustaceans (excluding crabs) of the Iberian Peninsula has been compiled 50 years after the publication of “Crustáceos decápodos ibéricos” by Zariquiey Álvarez (1968). A total of 294 species belonging to 136 genera and 48 families has been recorded. This information increases by 118 species the total number reported by Zariquiey Álvarez in his posthumous work. The families with the greatest species richness are the Paguridae (28) and Palaemonidae (18). References by geographic sectors and for all species are given. The results show that 264 species are reported in the Atlantic sectors, while 178 have been found in the Mediterranean. The species richness and the differences between and within sectors are discussed; these are mainly due to the dimension of the areas, the depth ranges and the confluence of distinct water masses with a different origin and different physicochemical features. Consequently, the greatest richness of decapod species (excluding crabs) is found in the Gulf of Cádiz, with 194 species. The total number of decapods found in and around Iberian waters, including crabs, freshwater species and some new records not yet published, reaches 449.
Paraules clau: Checklist; Decapoda Crustacea; Iberian Peninsula; Species richness; Lista inventario; Península ibérica; Riqueza de especie
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Lin W., M. Portabella, A. Stoffelen, A. Verhoef, Z. Wang
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Valencia, Spain, 22-27 July, 2018, . (BibTeX: lin.etal.2018b)
Resum: Veure
Recent developments on the wind geophysical model function (GMF) of Ku-band scatterometers include a sea surface temperature (SST) dependent term. It has been found that the SST effects on the radar backscatter are wind speed dependent and more pronounced in vertical polarization (VV) than in horizontal polarisation (HH) at higher incidence angles, and are mainly relevant at radar wavelengths smaller than C-band. The new Ku-band GMF, NSCAT-5, is developed based on a physical model and RapidScat radar backscatter measurements, which are only available at two incidence angles, i.e., 48.8⁰ and 55.2⁰, for HH and VV beams, respectively. The objective of this paper is to verify the NSCAT-5 GMF at similar incidence angles, using data from the scatterometer onboard Indian SCATSat-1 satellite, which operates at 49.1⁰ (HH) and 57.9⁰ (VV) incidence angles. First, the SCATSat-1 backscatter sensitivity to sea surface wind and SST is assessed using the C-band Advance Scatterometer (ASCAT) winds as reference. Second, the approach used to derive the NSCAT-5 GMF for RapidScat is adapted to derive a SST-dependent GMF for SCATSat-1. The new GMF will be used to consolidate the current NSCAT-5 model, and then evaluated for SCATSat-1 wind retrieval.
Paraules clau: Geophysical model function, scatterometer, sea surface temperature, wind
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Olivar M.P., T. Contreras, P.A. Hulley, M. Emelianov, C. López-Pérez, V. Tuset, A. Castellón
Progress in Oceanography, 160, 83-100. DOI: 10.1016/j.pocean.2017.12.005 (BibTeX: olivar.etal.2018)
Resum: Veure
The vertical distributions of early developmental stages of oceanic fishes were investigated across the tropical and equatorial Atlantic, from oligotrophic waters close to the Brazilian coast to more productive waters close to the Mauritanian Upwelling Region. Stratification of the water column was observed throughout the study region. Fishes were caught with a MOCNESS-1 net with mouth area of 1m2 at 11 stations. Each station was sampled both during the day and at night within a single 24-h period. The investigation covered both larvae and transforming stages from the surface to 800m depth. Distribution patterns were analysed, and weighted mean depths for the larvae and transforming stages of each species were calculated for day and night conditions. Fortyseven different species were found. The highest number of species occurred in the three stations south of Cape Verde Islands, characterized by a mixture of South Atlantic Central Water (SACW) and Eastern North Atlantic Central Water (ENACW). There was a marked drop in species richness in the three stations closer to the African upwelling, dominated by ENACW. The highest abundances occurred in the families Myctophidae, Sternoptychidae, Gonostomatidae and Phosichthyidae. Day and night vertical distributions of larvae and transforming stages showed contrasting patterns, both in the depths of the main concentration layers in the water column, and in the diel migration patterns (where these were observed). Larvae generally showed a preference for the upper mixed layer (ca. 0–50 m) and upper thermocline (ca. 50–100 m), except for sternoptychids, which were also abundant in the lower thermocline layer (100–200 m) and even extended into the mesopelagic zone (down to 500 m). Transforming stages showed a more widespread distribution, with main concentrations in the mesopelagic zone (200–800 m). Larvae showed peak concentrations in the more illuminated and zooplankton-rich upper mixed layers during the day and a wider distribution through the upper 100m during the night. For most species, transforming stages were concentrated in the mesopelagic layers both day and night, although in some species (Diaphus cf. vanhoeffeni and Vinciguerria nimbaria), the transforming stages displayed vertical migration into the upper 100m at night, in a manner similar to their adult stages.
Paraules clau: Early life-history Ontogenetic vertical migration Mesopelagic fishes Lanternfishes Lightfishes Hatchetfishes
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Salat J., P. Puig, M. Flexas, R. Balbin, A. Sabatés, J. Pascual
11 Congreso Internacional AEC. Cartagena 17-19 octubre 2018. Publicaciones de la Asociación Española de Climatología, . (BibTeX: salat.etal.2018)
Resum: Veure
Desde el invierno de 2013, no se han observado episodios relevantes de formación de aguas profundas en el Mediterráneo Occidental. Ello podría estar relacionado con la suavidad de estos últimos inviernos. No obstante, en 2018 sí ha habido episodios fríos importantes para producir aguas densas, pero no suficientes como para lograr cantidades significativas de nueva agua profunda. En la presente comunicación se plantea la posibilidad de que desde el agotamiento del agua profunda anterior al 2005 en toda la cuenca, en 2015 como más tarde, la formación de nueva agua profunda requiera unas pérdidas de calor latente superiores a las necesarias anteriormente. Este requerimiento, junto a la tendencia global al calentamiento podría causar un debilitamiento de la circulación termohalina mediterránea, con diversas consecuencias a escala regional y global. Entre ellas, una disminución de los intercambios de agua con el Océano y de los niveles de oxígeno en aguas profundas.
Paraules clau: Formación de aguas profundas, inviernos suaves, Mediterráneo Noroccidental, Cambio climático