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Auteur McLean, M.J.; Mouillot, D.; Goascoz, N.; Schlaich, I.; Auber, A.
Titre Functional reorganization of marine fish nurseries under climate warming Type Article scientifique
Année 2019 Publication Revue Abrégée Glob. Change Biol.
Volume (down) 25 Numéro 2 Pages 660-674
Mots-Clés English Channel; community; ecosystem; fisheries; recruitment; functional traits; in-situ; connectivity; estuarine; climate change; life-history strategies; ecosystem function; life history; english-channel; Atlantic Multidecadal Oscillation; atlantic multidecadal oscillation; fuzzy-logic; r-selection
Résumé While climate change is rapidly impacting marine species and ecosystems worldwide, the effects of climate warming on coastal fish nurseries have received little attention despite nurseries' fundamental roles in recruitment and population replenishment. Here, we used a 26-year time series (1987-2012) of fish monitoring in the Bay of Somme, a nursery in the Eastern English Channel (EEC), to examine the impacts of environmental and human drivers on the spatial and temporal dynamics of fish functional structure during a warming phase of the Atlantic Multidecadal Oscillation (AMO). We found that the nursery was initially dominated by fishes with r-selected life-history traits such as low trophic level, low age and size at maturity, and small offspring, which are highly sensitive to warming. The AMO, likely superimposed on climate change, induced rapid warming in the late 1990s (over 1 degrees C from 1998 to 2003), leading to functional reorganization of fish communities, with a roughly 80% decline in overall fish abundance and increased dominance by K-selected fishes. Additionally, historical overfishing likely rendered the bay more vulnerable to climatic changes due to increased dominance by fishing-tolerant, yet climatically sensitive species. The drop in fish abundance not only altered fish functional structure within the Bay of Somme, but the EEC was likely impacted, as the EEC has been unable to recover from a regime shift in the late 1990s potentially, in part, due to failed replenishment from the bay. Given the collapse of r-selected fishes, we discuss how the combination of climate cycles and global warming could threaten marine fish nurseries worldwide, as nurseries are often dominated by r-selected species.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1354-1013 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2523
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Auteur Amandé, M.; Ariz, J.; Chassot, E.; Molina, A.D. de; Gaertner, D.; Murua, H.; Pianet, R.; Ruiz, J.; Chavance, P.
Titre Bycatch of the European purse seine tuna fishery in the Atlantic Ocean for the 2003-2007 period Type Article scientifique
Année 2010 Publication Revue Abrégée Aquatic Living Resources
Volume (down) 23 Numéro 4 Pages 353-362
Mots-Clés atlantic Ocean; Bycatch; discards; Purse seining; Tuna fisheries
Résumé Bycatch of several groups of species and their characteristics are presented for the period 2003 to 2007 for the European purse seine tuna fishery operating in the Atlantic Ocean. Data were collected through French and Spanish observer programmes and represented a total of 27 trips corresponding to 2.9% coverage. Bycatch is defined as non-targeted species and small or damaged target species. Bycatch species composition, main species length, sex ratio and the fate of the most common species are presented first. Stratified ratios relative to landings of major commercial tunas were then used to estimate the total bycatch; these ratios were considered the most appropriate variable for extrapolation. Stratification was based on the fishing mode (free school vs. floating object), season (quarters) and spatial areas. The annual average bycatch was estimated at about 6400 t, corresponding to a mean annual value of 80.8 t per 1000 t of tuna landed or 7.5% of the total catch. Tunas represent 83% (67.2 t/1000 t) of the total bycatch, followed by other bony fishes (10%, 7.8 t/1000 t), billfishes (5%, 4.0 t/1000 t), sharks (1%, 0.9 t/1000 t) and rays (1%, 0.9 t/1000 t). Based on estimates of the annual bycatch, 16% was kept on board and sold in local markets.
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ISSN 0990-7440 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 56
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Auteur Bender, M.G.; Pie, M.R.; Rezende, E.L.; Mouillot, D.; Floeter, S.R.
Titre Biogeographic, historical and environmental influences on the taxonomic and functional structure of Atlantic reef fish assemblages Type Article scientifique
Année 2013 Publication Revue Abrégée Global Ecology and Biogeography
Volume (down) 22 Numéro 11 Pages 1173-1182
Mots-Clés Assemblage structuring; Atlantic Ocean; Body size; functional group; reef fish; taxonomic structure
Résumé Aim To disentangle how historic, biogeographic and environmental factors have shaped the composition of different reef fish assemblages, we analysed assemblage structure from a taxonomic (proportions of species from different families) and functional perspective (diet and body size). Location Atlantic Ocean. Methods The distributions of 1629 fish species were compiled for 31 locations across the Atlantic Ocean (39°66′ N, 27°50′ S). These locations provide a richness gradient ranging from 54 species in St Paul's Rocks to 474 in Cuba. We used cluster analyses to assess how historical and biogeographic factors have shaped the taxonomic and functional structure (i.e. the distribution of species within families, diet and body size groups) of assemblages. We then employed a constrained analysis of principal coordinates (CAP) to test the relative influence of the distance from the biodiversity centre in the Atlantic, sea surface temperature, isolation, coral species richness and area, and coastal length on the observed patterns of assemblage structure. Results The taxonomic and functional structure of reef fish assemblages across the Atlantic exhibits a biogeographic fingerprint, with a marked discrimination between species-rich biogenic reefs (concentrated primarily in the Caribbean and composed of small species feeding on invertebrates) and poorer peripheral regions dominated by larger species with more diverse diets. The first CAP axis explains 87% of body size distribution in assemblages, showing that the effects of sea surface temperature and coral richness and those of isolation are antagonistic and can be embedded into a single dimension. Environmental factors, such as temperature and habitat complexity, explain the disproportionate number of small species in the Caribbean, whereas in the remaining regions the predominance of large-bodied fish increases with isolation due to high dispersal ability. Main conclusions We found that historical events, which have shaped the biogeography of reef fishes, and environmental characteristics (coral reefs versus periphery) have both played a role in structuring the taxonomic and functional components of Atlantic fish assemblages.
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Volume de collection Numéro de collection Edition
ISSN 1466-8238 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 456
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Auteur Dueri, S.; Bopp, L.; Maury, O.
Titre Projecting the impacts of climate change on skipjack tuna abundance and spatial distribution Type Article scientifique
Année 2014 Publication Revue Abrégée Global Change Biology
Volume (down) 20 Numéro 3 Pages 742-753
Mots-Clés Apecosm-E; Atlantic Ocean; global warming; Indian Ocean; Katsuwonus pelamis; Pacific Ocean; scenario; Tropical tuna
Résumé Climate-induced changes in the physical, chemical, and biological environment are expected to increasingly stress marine ecosystems, with important consequences for fisheries exploitation. Here, we use the APECOSM-E numerical model (Apex Predator ECOSystem Model – Estimation) to evaluate the future impacts of climate change on the physiology, spatial distribution, and abundance of skipjack tuna, the worldwide most fished species of tropical tuna. The main novelties of our approach lie in the mechanistic link between environmental factors, metabolic rates, and behavioral responses and in the fully three dimensional representation of habitat and population abundance. Physical and biogeochemical fields used to force the model are provided by the last generation of the IPSL-CM5 Earth System Model run from 1990 to 2100 under a &8216;business-as-usual&8217; scenario (RCP8.5). Our simulations show significant changes in the spatial distribution of skipjack tuna suitable habitat, as well as in their population abundance. The model projects deterioration of skipjack habitat in most tropical waters and an improvement of habitat at higher latitudes. The primary driver of habitat changes is ocean warming, followed by food density changes. Our projections show an increase of global skipjack biomass between 2010 and 2050 followed by a marked decrease between 2050 and 2095. Spawning rates are consistent with population trends, showing that spawning depends primarily on the adult biomass. On the other hand, growth rates display very smooth temporal changes, suggesting that the ability of skipjack to keep high metabolic rates in the changing environment is generally effective. Uncertainties related to our model spatial resolution, to the lack or simplification of key processes and to the climate forcings are discussed.
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Editeur Lieu de Publication Éditeur
Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1354-1013 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 327
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Auteur Coelho, R.; Mejuto, J.; Domingo, A.; Yokawa, K.; Liu, K.-M.; Cortes, E.; Romanov, E.V.; da Silva, C.; Hazin, F.; Arocha, F.; Mwilima, A.M.; Bach, P.; Ortiz de Zarate, V.; Roche, W.; Lino, P.G.; Garcia-Cortes, B.; Ramos-Cartelle, A.M.; Forselledo, R.; Mas, F.; Ohshimo, S.; Courtney, D.; Sabarros, P.S.; Perez, B.; Wogerbauer, C.; Tsai, W.-P.; Carvalho, F.; Santos, M.N.
Titre Distribution patterns and population structure of the blue shark (Prionace glauca) in the Atlantic and Indian Oceans Type Article scientifique
Année 2018 Publication Revue Abrégée Fish. Fish.
Volume (down) 19 Numéro 1 Pages 90-106
Mots-Clés Atlantic Ocean; Indian Ocean; size distribution; spatial distribution; relative abundance; north-atlantic; caribbean sea; elasmobranchs caught; fishery observer programmes; pelagic fisheries; pelagic sharks
Résumé The blue shark (Prionace glauca) is the most frequently captured shark in pelagic oceanic fisheries, especially pelagic longlines targeting swordfish and/or tunas. As part of cooperative scientific efforts for fisheries and biological data collection, information from fishery observers, scientific projects and surveys, and from recreational fisheries from several nations in the Atlantic and Indian Oceans was compiled. Data sets included information on location, size and sex, in a total of 478,220 blue shark records collected between 1966 and 2014. Sizes ranged from 36 to 394cm fork length. Considerable variability was observed in the size distribution by region and season in both oceans. Larger blue sharks tend to occur in equatorial and tropical regions, and smaller specimens in higher latitudes in temperate waters. Differences in sex ratios were also detected spatially and seasonally. Nursery areas in the Atlantic seem to occur in the temperate south-east off South Africa and Namibia, in the south-west off southern Brazil and Uruguay, and in the north-east off the Iberian Peninsula and the Azores. Parturition may occur in the tropical north-east off West Africa. In the Indian Ocean, nursery areas also seem to occur in temperate waters, especially in the south-west Indian Ocean off South Africa, and in the south-east off south-western Australia. The distributional patterns presented in this study provide a better understanding of how blue sharks segregate by size and sex, spatially and temporally, and improve the scientific advice to help adopt more informed and efficient management and conservation measures for this cosmopolitan species.
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Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1467-2960 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2253
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