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Auteur Afandi, I.; Talba, S.; Benhra, A.; Benbrahim, S.; Chfiri, R.; Labonne, M.; Masski, H.; Laë, R.; Tito De Morais, L.; Bekkali, M.; Bouthir, F.Z.
Titre Trace metal distribution in pelagic fish species from the north-west African coast (Morocco) Type Article scientifique
Année 2018 Publication (down) Revue Abrégée Int Aquat Res
Volume 10 Numéro 2 Pages 191-205
Mots-Clés Bioaccumulation; Pelagic fish; South Atlantic coast of Morocco; Trace metals; Upwelling
Résumé In the current study, ten elements contents (Fe, Zn, Mn, Cu, Cr, Co, Ni, Cd, Pb and Hg) have been measured in muscle and liver of four pelagic fish species (Engraulis encrasicolus, Sardina pilchardus, Scomber japonicus and Trachurus trachurus) from the north-west African coast (South Atlantic Moroccan coast), collected during summer and autumn seasons (July and December 2013, respectively). Significant differences in metal contents were found between the different species (p < 0.05). Metals levels were also much higher in liver than those recorded in muscle tissues. The concentrations of Fe, Zn, Cd, Co, Cu and Pb were significantly higher in mackerel liver (p < 0.05).While, in muscle, anchovy presents a higher content of Mn, Cu, Cr, Ni and Pb. A high level of cadmium was recorded in liver of the different species which can be attributed to an anthropogenic source (phosphate industry) and to natural sources (upwelling activities). The main concentration of toxic elements (Cd, Pb and Hg) recorded in the four edible muscles of pelagic fish species, under study, were below the established values by the European Commission Regulations and show that their effect on the consumers health can be considered as negligible.
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ISSN 2008-6970 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2513
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Auteur Rouyer, T.; Bonhommeau, S.; Giordano, N.; Giordano, F.; Ellul, S.; Ellul, G.; Deguara, S.; Wendling, B.; Bernard, S.; Kerzerho, V.
Titre Tagging Atlantic bluefin tuna from a Mediterranean spawning ground using a purse seiner Type Article scientifique
Année 2020 Publication (down) Revue Abrégée Fish Res.
Volume 226 Numéro Pages 105522
Mots-Clés Eastern Atlantic and Mediterranean stock; Electronic tagging; Large Atlantic bluefin tuna; migration; Migrations; movements; population-structure; Purse seine; thermal biology; thunnus-thynnus
Résumé Atlantic bluefin tuna, Thunnus thynnus, is as an emblematic and commercially valuable large pelagic species. In the past ten years, the purse seine fishery in the Mediterranean represents more than 50 % of the catch. Nowadays, purse seines target large fish and operate during the spawning season in the spawning grounds. Electronic tagging has shed a considerable amount of light on the ecology and behaviour of bluefin tuna over the past twenty years. However, such technique has rarely been applied on large bluefin tunas caught by the Mediterranean purse seine fishery despite its major importance. The logistical constraints related to this specific fishery, combined with the timing of migration of the fish and the requirements related to the handling of big fish have made adequate tagging from purse seines complex. Here we detail such an operation, designed to bridge the knowledge gap on the migratory behaviour of tunas targeted by the purse seine fishery. Three large bluefin tunas from the same school were tagged during the fishing operation of a French purse seine, resulting in a different migration pattern than previous deployments. The fish were tagged onboard in less than 2 min and efficiently, avoiding any subsequent mortality. These results contrast with those from tagging operations carried out in the Northwest Mediterranean, which underlies the importance of tagging operations from purse seines to obtain unbiased description of the movements of the eastern Atlantic bluefin tuna stock in the context of its management.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0165-7836 ISBN Médium
Région Expédition Conférence
Notes WOS:000525305200010 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2771
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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 (down) Revue Abrégée Glob. Change Biol.
Volume 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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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 Mannocci, L.; Roberts, J.J.; Pedersen, E.J.; Halpin, P.N.
Titre Geographical differences in habitat relationships of cetaceans across an ocean basin Type Article scientifique
Année 2020 Publication (down) Revue Abrégée Ecography
Volume Numéro Pages
Mots-Clés associations; atlantic; conservation; distribution models; diversity; environmental predictors; geographical variation; habitat relationships; highly mobile marine species; marine mammals; North Atlantic Ocean; populations; predator; species distribution modeling; temperature; whales
Résumé The distributions of highly mobile marine species such as cetaceans are increasingly modeled at basin scale by combining data from multiple regions. However, these basin-wide models often overlook geographical variations in species habitat relationships between regions. We tested for geographical variations in habitat relationships for a suite of cetacean taxa between the two sides of the North Atlantic basin. Using cetacean visual survey data and remote sensing data from the western and eastern basin in summer, we related the probability of presence of twelve cetacean taxa from three guilds to seafloor depth, sea surface temperature and primary productivity. In a generalized additive model framework, we fitted 1) basin-wide (BW) models, assuming a single global relationship, 2) region-specific intercepts (RI) models, assuming relationships with the same shape in both regions, but allowing a region-specific intercept and 3) region-specific shape (RS) models, assuming relationships with different shapes between regions. RS models mostly yielded significantly better fits than BW models, indicating cetacean occurrences were better modeled with region-specific than with global relationships. The better fits of RS models over RI models further provided statistical evidence for differences in the shapes of region-specific relationships. Baleen whales showed striking differences in both the shapes of relationships and their mean presence probabilities between regions. Deep diving whales and delphinoids showed contrasting relationships between regions with few exceptions (e.g. non-statistically different shapes of region-specific relationships for harbor porpoise and beaked whales with depth). Our findings stress the need to account for geographical differences in habitat relationships between regions when modeling species distributions from combined data at the basin scale. Our proposed hypotheses offer a roadmap for understanding why habitat relationships may geographically vary in cetaceans and other highly mobile marine species.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0906-7590 ISBN Médium
Région Expédition Conférence
Notes WOS:000531110000001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2792
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Auteur Alfonso, S.; Sadoul, B.; Cousin, X.; Begout, M.-L.
Titre Spatial distribution and activity patterns as welfare indicators in response to water quality changes in European sea bass, Dicentrarchus labrax Type Article scientifique
Année 2020 Publication (down) Revue Abrégée Appl. Anim. Behav. Sci.
Volume 226 Numéro Pages Unsp-104974
Mots-Clés ammonia toxicity; atlantic salmon; avoidance-behavior; behavioral-responses; Behaviour; current issues; Fish; hyperoxia; hypoxia tolerance; marine fish; rainbow-trout; Stress; stress-response; Water quality; Welfare
Résumé In aquaculture, fish are exposed to unavoidable stressors that can be detrimental for their health and welfare. However, welfare in farmed fish can be difficult to assess, and, so far, no standardized test has been universally accepted as a welfare indicator. This work contributes to the establishment of behavioural welfare indicators in a marine teleost in response to different water quality acute stressors. Groups of ten fish were exposed to high Total Ammonia Nitrogen concentration (High TAN, 18 mg.L-1), Hyperoxia (200 % O-2 saturation), Hypoxia (20 % O-2 saturation), or control water quality (100% O-2 saturation and TAN < 2.5 mg.L-1) over 1 hour. Fish were then transferred in a novel environment for a group behaviour test under the same water quality conditions over 2 hours. Videos were recorded to assess thigmotaxis, activity and group cohesion. After this challenge, plasma cortisol concentration was measured in a subsample, while individual behavioural response was measured in the other fish using novel tank diving test. Prior to this study, the novel tank diving test was validated as a behavioural challenge indicative of anxiety state, by using nicotine as anxiolytic drug. Overall, all stress conditions induced a decrease in activity and thigmotaxis and changes in group cohesion while only fish exposed to Hypoxia and High TAN conditions displayed elevated plasma cortisol concentrations. In post-stress condition, activity was still affected but normal behaviour was recovered within the 25 minutes of the test duration. Our work suggests that the activity, thigmotaxis and group cohesion are good behavioural indicators of exposure to degraded water quality, and could be used as standardized measures to assess fish welfare.
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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 0168-1591 ISBN Médium
Région Expédition Conférence
Notes WOS:000531095400002 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2794
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