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Auteur ROUYER, T.; FROMENTIN, J.-M.; HIDALGO, M.; STENSETH, N.C.
Titre Combined effects of exploitation and temperature on fish stocks in the Northeast Atlantic Type Article scientifique
Année 2014 Publication (down) Ices Journal Of Marine Science Revue Abrégée
Volume 71 Numéro 7 Pages 1554-1562
Mots-Clés combined climate/exploitation effect; exploitation; fish stocks; Northeast Atlantic; response to climate; time-series
Résumé Fish stock fluctuations are affected by two potentially confounding forces: the removal of individuals by fisheries and climatic variations affecting the productivity of fish populations. Disentangling the relative importance of these forces has thus been a question of primary importance for fisheries management and conservation. Through the analysis of long-term time-series for 27 fish stocks from the Northeast Atlantic, the present study shows that the sign and intensity of the effect of temperature on biomass are dependent on the geographical location: the stocks located at the southernmost and northernmost latitudes of our study displayed stronger associations with temperature than the stocks located in the middle range of latitudes. As a consequence, the investigation of the combined effects of exploitation and the environment revealed that the stocks at the northern/southern boundaries of the spatial extent of the species were more prone to combined effects. The interplay between geographic location, climate and exploitation thus plays a significant role in fish stock productivity, which is generally ignored during assessment, thus affecting management procedures.
Adresse Inst Marine Res, Dept Coastal Zone Studies, Flodevigen Res Stn, N-4817 His, Norway.
Auteur institutionnel Thèse
Editeur Oxford Univ Press Lieu de Publication Éditeur
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Volume de collection Numéro de collection Edition
ISSN 1054-3139 ISBN Médium
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Auteur de Verdal, H.; O'Connell, C.M.; Mekkawy, W.; Vandeputte, M.; Chatain, B.; Begout, M.-L.; Benzie, J.A.H.
Titre Agonistic behaviour and feed efficiency in juvenile Nile tilapia Oreochromis niloticus Type Article scientifique
Année 2019 Publication (down) Revue Abrégée Aquaculture
Volume 505 Numéro Pages 271-279
Mots-Clés Agonstic behaviour; arctic charr; atlantic salmon; brain serotonergic activity; brown trout; conversion ratio; Correlation; dominance relationships; Feed efficiency; food acquisition; genetic-improvement; Nile tilapia; Performances; salvelinus-alpinus; social-status
Résumé Given the strong effects of behavioural hierarchies on growth in many cultured species and the key role of feed efficiency in aquaculture economics, understanding the nature of the interaction of these variables is important for the sustainability of aquaculture. The relationship between agonistic behaviour, growth and feed efficiency in Nile tilapia, Oreochromis niloticus, was studied by rearing 120 fish in eight aquaria. Fish were video-recorded to estimate the occurrence of agonistic behaviour during a fasting and a refeeding period. Growth, feed intake and feed conversion efficiency (FCE – calculated as the inverse of feed conversion ratio (FCR)) were subsequently measured individually for each fish. Fish showed 58% less agonistic traits during the fasting period compared to the feeding period, but generally, an aggressive fish during the fasting period was also aggressive during the refeeding period. The nature of agonistic behaviours between individuals was used to assess the presence of hierarchical relationships between fish. There were dominance hierarchies established in each experimental aquarium that despite minor shifts were maintained throughout the experiment. Agonistic behaviours were strongly correlated with each other, the aggression Index (AI) and with hierarchy rank. PCA analysis of the agonistic behaviours summarising the behavioural information showed little or no correlation between agonistic behaviour, fish growth or FCE. FCE was correlated with body weight gain (BWG). These results suggest that agonistic interactions in juvenile Nile tilapia do not have a large impact on growth and feed conversion efficiency.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0044-8486 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2583
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Auteur Boavida, J.; Becheler, R.; Choquet, M.; Frank, N.; Taviani, M.; Bourillet, J.-F.; Meistertzheim, A.-L.; Grehan, A.; Savini, A.; Arnaud-Haond, S.
Titre Out of the Mediterranean? Post-glacial colonization pathways varied among cold-water coral species Type Article scientifique
Année 2019 Publication (down) Revue Abrégée J. Biogeogr.
Volume 46 Numéro 5 Pages 915-931
Mots-Clés biodiversity; cold-water corals; computer-program; deep-sea; deep-sea corals; genetic-structure; glacial marine refugia; glacial refugia; growth; in-situ; Last Glacial Maximum; Lophelia pertusa; lophelia-pertusa; Madrepora oculata; marine phylogeography; north-atlantic ocean; software
Résumé Aim: To infer cold-water corals' (CWC) post-glacial phylogeography and assess the role of Mediterranean Sea glacial refugia as origins for the recolonization of the northeastern Atlantic Ocean. Location: Northeastern Atlantic Ocean and Mediterranean Sea. Taxon: Lophelia pertusa, Madrepora oculata. Methods: We sampled CWC using remotely operated vehicles and one sediment core for coral and sediment dating. We characterized spatial genetic patterns (microsatellites and a nuclear gene fragment) using networks, clustering and measures of genetic differentiation. Results: Inferences from microsatellite and sequence data were congruent, and showed a contrast between the two CWC species. Populations of L. pertusa present a dominant pioneer haplotype, local haplotype radiations and a majority of endemic variation in lower latitudes. Madrepora oculata populations are differentiated across the northeastern Atlantic and genetic lineages are poorly admixed even among neighbouring sites. Conclusions: Our study shows contrasting post-glacial colonization pathways for two key habitat-forming species in the deep sea. The CWC L. pertusa has likely undertaken a long-range (post-glacial) recolonization of the northeastern Atlantic directly from refugia located along southern Europe (Mediterranean Sea or Gulf of Cadiz). In contrast, the stronger genetic differentiation of M. oculata populations mirrors the effects of long-term isolation in multiple refugia. We suggest that the distinct and genetically divergent, refugial populations initiated the post-glacial recolonization of the northeastern Atlantic margins, leading to a secondary contact in the northern range and reaching higher latitudes much later, in the late Holocene. This study highlights the need to disentangle the influences of present-day dispersal and evolutionary processes on the distribution of genetic polymorphisms, to unravel the influence of past and future environmental changes on the connectivity of cosmopolitan deep-sea ecosystems associated with CWC.
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Volume de collection Numéro de collection Edition
ISSN 0305-0270 ISBN Médium
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Notes WOS:000471344900007 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2602
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Auteur Cocquempot, L.; Delacourt, C.; Paillet, J.; Riou, P.; Aucan, J.; Castelle, B.; Charria, G.; Claudet, J.; Conan, P.; Coppola, L.; Hocdé, R.; Planes, S.; Raimbault, P.; Savoye, N.; Testut, L.; Vuillemin, R.
Titre Coastal Ocean and Nearshore Observation: A French Case Study Type Article scientifique
Année 2019 Publication (down) Revue Abrégée Front. Mar. Sci.
Volume 6 Numéro Pages Unsp-324
Mots-Clés 2013/2014 winter; atlantic coast; coastal ocean; coastline; diversity; ecosystem; increases; interdisciplinary; national structuration; nutrient ratios; observation infrastructure; phytoplankton community; temperature; variability; wave activity
Résumé To understand and predict the physical, chemical, and biological processes at play in coastal and nearshore marine areas requires an integrated, interdisciplinary approach. The case study of the French structuration of coastal ocean and nearshore observing systems provides an original overview on a federative research infrastructure named ILICO. It is a notable example of national structuration and pan-institution efforts to investigate the forefront of knowledge on the processes at work within the critical coastal zone. ILICO comprises, in a pluridisciplinary approach, eight distributed network-systems of observation and data analysis that are accredited and financially supported by French research institutions and the French Ministry for Higher Education, Research, and Innovation. ILICO observation points are implemented along metropolitan and overseas French coasts, where coastline dynamics, sea level evolution, physical and biogeochemical water properties, coastal water dynamics, phytoplankton composition, and health of coral reefs are monitored in order to address a wide range of scientific questions. To give an overview of the diversity and potential of the observations carried out, this paper offers a detailed presentation of three constituting networks: Service Observation en Milieu LITtoral (SOMLIT), with homogeneous sampling strategies, DYNALIT, with heterogeneous sampling strategies adapted to different environments, and Mediterranean Ocean Observing System for the Environment (MOOSE), an integrated, pluri-disciplinary coasta/offshore regional observatory in the north-western Mediterranean Sea. ILICO was conceived using a European framework. It addresses the great challenges of the next decade in terms of sustainability, cost-efficiency, interoperability, and innovation. This paper emphasizes the added-value of federating these systems, and highlights some recommendations for the future.
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Langue English Langue du Résumé Titre Original
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Auteur Escalle, L.; Pennino, M.G.; Gaertner, D.; Chavance, P.; Delgado de Molina, A.; Demarcq, H.; Romanov, E.; Mérigot, B.
Titre Environmental factors and megafauna spatio-temporal co-occurrence with purse-seine fisheries Type Article scientifique
Année 2016 Publication (down) Revue Abrégée Fish. Oceanogr.
Volume 25 Numéro 4 Pages 433-447
Mots-Clés cetaceans; Eastern Atlantic Ocean; generalized additive models-boosted regression trees; marine conservation; purse-seine fishery; residual autocovariate; Western Indian Ocean; whale sharks
Résumé Tropical tuna purse-seine fisheries spatially co-occur with various megafauna species, such as whale sharks, dolphins and baleen whales in all oceans of the world. Here, we analyzed a 10-year (2002–2011) dataset from logbooks of European tropical tuna purse-seine vessels operating in the tropical Eastern Atlantic and Western Indian Oceans, with the aim of identifying the principle environmental variables under which such co-occurrence appear. We applied a Delta-model approach using Generalized Additive Models (GAM) and Boosted Regression Trees (BRT) models, accounting for spatial autocorrelation using a contiguity matrix based on a residuals autocovariate (RAC) approach. The variables that contributed most in the models were chlorophyll-a concentration in the Atlantic Ocean, as well as depth and monsoon in the Indian Ocean. High co-occurrence between whale sharks, baleen whales and tuna purse-seine fisheries were mostly observed in productive areas during particular seasons. In light of the lack of a full coverage scientific observer on board program, the large, long-term dataset obtained from logbooks of tuna purse-seine vessels is highly important for identifying seasonal and spatial co-occurrence between the distribution of fisheries and megafauna, and the underlying environmental variables. This study can help to design conservation management measures for megafauna species within the framework of spatial fishery management strategies.
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ISSN 1365-2419 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1587
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