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Auteur Chouvelon, T.; Brach-Papa, C.; Auger, D.; Bodin, N.; Bruzac, S.; Crochet, S.; Degroote, M.; Hollanda, S.J.; Hubert, C.; Knoery, J.; Munschy, C.; Puech, A.; Rozuel, E.; Thomas, B.; West, W.; Bourjea, J.; Nikolic, N.
Titre (up) Chemical contaminants (trace metals, persistent organic pollutants) in albacore tuna from western Indian and south-eastern Atlantic Oceans: Trophic influence and potential as tracers of populations Type Article scientifique
Année 2017 Publication Revue Abrégée Sci. Total Environ.
Volume 596 Numéro Pages 481-495
Mots-Clés Bioaccumulation; biscay northeast atlantic; enhanced bioaccumulation; feeding ecology; Inorganic elements; Intrinsic markers; marine food webs; mercury concentrations; merluccius-merluccius; Organic contaminants; organochlorine compounds; polychlorinated-biphenyls; stable-isotope analysis; Stable isotopes; thunnus-alalunga; Top predator
Résumé Albacore tuna (Thunnus alalunga) is a highly commercial fish species harvested in the world's Oceans. Identifying the potential links between populations is one of the key tools that can improve the current management across fisheries areas. In addition to characterising populations' contamination state, chemical compounds can help refine foraging areas, individual flows and populations' structure, especially when combined with other intrinsic biogeochemical (trophic) markers such as carbon and nitrogen stable isotopes. This study investigated the bioaccumulation of seven selected trace metals – chromium, nickel, copper (Cu), zinc (Zn), cadmium (Cd), mercury (Hg) and lead – in the muscle of 443 albacore tunas, collected over two seasons and/or years in the western Indian Ocean (WIO: Reunion Island and Seychelles) and in the south-eastern Atlantic Ocean (SEAO: South Africa). The main factor that explained metal concentration variability was the geographic origin of fish, rather than the size and the sex of individuals, or the season/year of sampling. The elements Cu, Zn, Cd and Hg indicated a segregation of the geographic groups most clearly. For similar sized-individuals, tunas from SEAO had significantly higher concentrations in Cu, Zn and Cd, but lower Hg concentrations than those from WIO. Information inferred from the analysis of trophic markers (delta C-13, delta N-15) and selected persistent organic pollutants, as well as information on stomach contents, corroborated the geographical differences obtained by trace metals. It also highlighted the influence of trophic ecology on metal bioaccumulation. Finally, this study evidenced the potential of metals and chemical contaminants in general as tracers, by segregating groups of individuals using different food webs or habitats, to better understand spatial connectivity at the population scale. Limited flows of individuals between the SEAO and the WIO are suggested. Albacore as predatory fish also provided some information on environmental and food web chemical contamination in the different study areas. (C) 2017 Elsevier B.V. All rights reserved.
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Langue English Langue du Résumé Titre Original
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ISSN 0048-9697 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2139
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Auteur Albo-Puigserver, M.; Munoz, A.; Navarro, J.; Coll, M.; Pethybridge, H.; Sanchez, S.; Palomera, I.
Titre (up) Ecological energetics of forage fish from the Mediterranean Sea: Seasonal dynamics and interspecific differences Type Article scientifique
Année 2017 Publication Revue Abrégée Deep-Sea Res. Part II-Top. Stud. Oceanogr.
Volume 140 Numéro Pages 74-82
Mots-Clés anchovy engraulis-encrasicolus; Bioenergetics; climate-change; diet composition; Energy density; environmental variability; feeding-habits; food webs; horse mackerel; Mediterranean Sea; north aegean sea; osteichthyes carangidae; sardine sardina-pilchardus; small pelagic fish
Résumé Small and medium pelagic fishes play a central role in marine food webs by transferring energy from plankton to top predators. In this study, direct calorimetry was used to analyze the energy density of seven pelagic species collected over four seasons from the western Mediterranean Sea: anchovy Engraulis encrasicolus, sardine Sardina pilchardus, round sardinella Sardinella aurita, horse mackerels Trachurus trachurus and T. mediterraneus, and mackerels Scomber scombrus and S. colias. Inter-specific differences in energy density were linked to spawning period, energy allocation strategies for reproduction and growth, and feeding ecologies. Energy density of each species varied over time, with the exception of S. colitis, likely due to its high energetic requirements related to migration throughout the year. In general, higher energy density was observed in spring for all species, regardless of their breeding strategy, probably as a consequence of the late-winter phytoplankton bloom. These results provide new insights into the temporal availability of energy in the pelagic ecosystem of the Mediterranean Sea, which are pivotal for understanding how the population dynamics of small and medium pelagic fishes and their predators may respond to environmental changes and fishing impacts. In addition, the differences found in energy density between species highlighted the importance of using species specific energy values in ecosystem assessment tools such as bioenergetic and food web models.
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Volume de collection Numéro de collection Edition
ISSN 0967-0645 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2176
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Auteur Jacquet, C.; Mouillot, D.; Kulbicki, M.; Gravel, D.
Titre (up) Extensions of Island Biogeography Theory predict the scaling of functional trait composition with habitat area and isolation Type Article scientifique
Année 2017 Publication Revue Abrégée Ecol. Lett.
Volume 20 Numéro 2 Pages 135-146
Mots-Clés Allometric theory; animal abundance; body-size; body-size distributions; complex food webs; coral-reef fishes; diversity; Ecology; evolution; Food web; global patterns; island biogeography; population-density; species richness; tropical reefs
Résumé The Theory of Island Biogeography (TIB) predicts how area and isolation influence species richness equilibrium on insular habitats. However, the TIB remains silent about functional trait composition and provides no information on the scaling of functional diversity with area, an observation that is now documented in many systems. To fill this gap, we develop a probabilistic approach to predict the distribution of a trait as a function of habitat area and isolation, extending the TIB beyond the traditional species-area relationship. We compare model predictions to the body-size distribution of piscivorous and herbivorous fishes found on tropical reefs worldwide. We find that small and isolated reefs have a higher proportion of large-sized species than large and connected reefs. We also find that knowledge of species body-size and trophic position improves the predictions of fish occupancy on tropical reefs, supporting both the allometric and trophic theory of island biogeography. The integration of functional ecology to island biogeography is broadly applicable to any functional traits and provides a general probabilistic approach to study the scaling of trait distribution with habitat area and isolation.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1461-023x ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2087
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Auteur Campbell, S.J.; Darling, E.S.; Pardede, S.; Ahmadia, G.; Mangubhai, S.; Amkieltiela; Estradivari; Maire, E.
Titre (up) Fishing restrictions and remoteness deliver conservation outcomes for Indonesia's coral reef fisheries Type Article scientifique
Année 2020 Publication Revue Abrégée Conserv. Lett.
Volume Numéro Pages e12698
Mots-Clés data-poor fisheries; dynamics; food webs; gear restrictions; management; marine protected areas; small-scale fisheries; South East Asia; targets
Résumé Coral reef fisheries depend on reef fish biomass to support ecosystem functioning and sustainable fisheries. Here, we evaluated coral reefs across 4,000 km of the Indonesian archipelago to reveal a large gradient of biomass, from 17,000 kg/ha. Trophic pyramids characterized by planktivore dominance emerged at high biomass, suggesting the importance of pelagic pathways for reef productivity. Total biomass and the biomass of most trophic groups were higher within gear restricted and no-take management, but the greatest biomass was found on unmanaged remote reefs. Within marine protected areas (MPAs), 41.6% and 43.6% of gear restricted and no-take zones, respectively, met a global biomass target of 500 kg/ha, compared with 71.8% of remote sites. To improve conservation outcomes for Indonesia's biodiverse and economically important coral reef fisheries, our results suggest to: (1) strengthen management within Indonesia's existing MPAs and (2) precautionarily manage remote reefs with high biomass.
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Éditeur de collection Titre de collection Titre de collection Abrégé
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ISSN 1755-263x ISBN Médium
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Notes WOS:000510789900001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2733
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Auteur Lotze, H.K.; Tittensor, D.P.; Bryndum-Buchholz, A.; Eddy, T.D.; Cheung, W.W.L.; Galbraith, E.D.; Barange, M.; Barrier, N.; Bianchi, D.; Blanchard, J.L.; Bopp, L.; Büchner, M.; Bulman, C.M.; Carozza, D.A.; Christensen, V.; Coll, M.; Dunne, J.P.; Fulton, E.A.; Jennings, S.; Jones, M.C.; Mackinson, S.; Maury, O.; Niiranen, S.; Oliveros-Ramos, R.; Roy, T.; Fernandes, J.A.; Schewe, J.; Shin, Y.-J.; Silva, T.A.M.; Steenbeek, J.; Stock, C.A.; Verley, P.; Volkholz, J.; Walker, N.D.; Worm, B.
Titre (up) Global ensemble projections reveal trophic amplification of ocean biomass declines with climate change Type Article scientifique
Année 2019 Publication Revue Abrégée Pnas
Volume 116 Numéro 26 Pages 12907-12912
Mots-Clés climate change impacts; global ecosystem modeling; marine food webs; model intercomparison; uncertainty
Résumé While the physical dimensions of climate change are now routinely assessed through multimodel intercomparisons, projected impacts on the global ocean ecosystem generally rely on individual models with a specific set of assumptions. To address these single-model limitations, we present standardized ensemble projections from six global marine ecosystem models forced with two Earth system models and four emission scenarios with and without fishing. We derive average biomass trends and associated uncertainties across the marine food web. Without fishing, mean global animal biomass decreased by 5% (±4% SD) under low emissions and 17% (±11% SD) under high emissions by 2100, with an average 5% decline for every 1 °C of warming. Projected biomass declines were primarily driven by increasing temperature and decreasing primary production, and were more pronounced at higher trophic levels, a process known as trophic amplification. Fishing did not substantially alter the effects of climate change. Considerable regional variation featured strong biomass increases at high latitudes and decreases at middle to low latitudes, with good model agreement on the direction of change but variable magnitude. Uncertainties due to variations in marine ecosystem and Earth system models were similar. Ensemble projections performed well compared with empirical data, emphasizing the benefits of multimodel inference to project future outcomes. Our results indicate that global ocean animal biomass consistently declines with climate change, and that these impacts are amplified at higher trophic levels. Next steps for model development include dynamic scenarios of fishing, cumulative human impacts, and the effects of management measures on future ocean biomass trends.
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ISSN 0027-8424, 1091-6490 ISBN Médium
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Notes WOS:000472719100059 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2586
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