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Auteur Rouyer, T.; Fromentin, J.-M.; Ménard, F.; Cazelles, B.; Briand, K.; Pianet, R.; Planque, B.; Stenseth, N.C.
Titre Complex interplays among population dynamics, environmental forcing, and exploitation in fisheries Type Article scientifique
Année 2008 Publication (down) Revue Abrégée Pnas
Volume 105 Numéro 14 Pages 5420-5425
Mots-Clés Atlantic tuna; North Atlantic Oscillation; time-series analysis
Résumé The patterns of variations in fisheries time series are known to result from a complex combination of species and fisheries dynamics all coupled with environmental forcing (including climate, trophic interactions, etc.). Disentangling the relative effects of these factors has been a major goal of fisheries science for both conceptual and management reasons. By examining the variability of 169 tuna and billfish time series of catch and catch per unit effort (CPUE) throughout the Atlantic as well as their linkage to the North Atlantic Oscillation (NAO), we find that the importance of these factors differed according to the spatial scale. At the scale of the entire Atlantic the patterns of variations are primarily spatially structured, whereas at a more regional scale the patterns of variations were primarily related to the fishing gear. Furthermore, the NAO appeared to also structure the patterns of variations of tuna time series, especially over the North Atlantic. We conclude that the patterns of variations in fisheries time series of tuna and billfish only poorly reflect the underlying dynamics of these fish populations; they appear to be shaped by several successive embedded processes, each interacting with each other. Our results emphasize the necessity for scientific data when investigating the population dynamics of large pelagic fishes, because CPUE fluctuations are not directly attributable to change in species' abundance.
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Volume de collection Numéro de collection Edition
ISSN 0027-8424, 1091-6490 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1669
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Auteur Brophy, D.; Haynes, P.; Arrizabalaga, H.; Fraile, I.; Fromentin, J.-M.; Garibaldi, F.; Katavic, I.; Tinti, F.; Karakulak, F.S.; Macias, D.; Busawon, D.; Hanke, A.; Kimoto, A.; Sakai, O.; Deguara, S.; Abid, N.; Santos, M.N.
Titre Otolith shape variation provides a marker of stock origin for north Atlantic bluefin tuna (Thunnus thynnus) Type Article scientifique
Année 2016 Publication (down) Revue Abrégée Mar. Freshw. Res.
Volume 67 Numéro 7 Pages 1023-1036
Mots-Clés carrying-capacity; elliptical Fourier analysis; fish; holistic approach; identification; management; Mediterranean Sea; mitochondrial-dna; population structure; population-structure; spatial structure; stock mixture analysis; western atlantic
Résumé Two stocks of bluefin tuna (Thunnus thynnus) inhabit the north Atlantic; the western and eastern stocks spawn in the Gulf of Mexico and the Mediterranean Sea respectively. Trans-Atlantic movements occur outside spawning time whereas natal homing maintains stock structure. Commercial fisheries may exploit a mixed assemblage of both stocks. The incorporation of mixing rates into stock assessment is precluded by uncertainties surrounding stock discrimination. Otolith shape descriptors were used to characterise western and eastern stocks of Atlantic bluefin tuna in the present study and to estimate stock composition in catches of unknown origin. Otolith shape varied with length and between locations and years. Within a restricted size range (200-297-cm fork length (FL)) the two stocks were distinguished with an accuracy of 83%. Bayesian stock mixture analysis indicated that samples from the east Atlantic and Mediterranean were predominantly of eastern origin. The proportion assigned to the eastern stock showed slight spatial variation; however, overlapping 95% credible intervals indicated no significant difference (200-297 cm FL: central Atlantic, 73-100%; Straits of Gibraltar, 73-100%; Morocco, 50-99%; Portugal 64-100%). Otolith shape could be used in combination with other population markers to improve the accuracy of mixing rate estimates for Atlantic bluefin tuna.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1323-1650 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1681
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Auteur Sbrana, M.; Zupa, W.; Ligas, A.; Capezzuto, F.; Chatzispyrou, A.; Follesa, M.C.; Gancitano, V.; Guijarro, B.; Isajlovic, I.; Jadaud, A.; Markovic, O.; Micallef, R.; Peristeraki, P.; Piccinetti, C.; Thasitis, I.; Carbonara, P.
Titre Spatiotemporal abundance pattern of deep-water rose shrimp, Parapenaeus longirostris, and Norway lobster, Nephrops norvegicus, in European Mediterranean waters Type Article scientifique
Année 2019 Publication (down) Revue Abrégée Sci. Mar.
Volume 83 Numéro Pages 71-80
Mots-Clés 1846 decapoda; atlantic; catch; crustacea; distribution; dynamics; fishery; lucas; Mediterranean Sea; merluccius-merluccius; Nephrops norvegicus; Parapenaeus longirostris; population; trawl survey; tyrrhenian sea
Résumé The main characteristics concerning the distribution of two of the most important decapod crustaceans of commercial interest in the Mediterranean Sea, the deep-water rose shrimp, Parapenaeus longirostris, and the Norway lobster. Nephrops norvegicus, are studied in the European Mediterranean waters. The study is based on data collected under the MEDITS trawl surveys from 1994 to 2015 from the Gibraltar Straits to the northeastern Levantine Basin (Cyprus waters). The observed differences can be interpreted as different responses to environmental drivers related to the differing life history traits of the two species. In fact, N. norvegicus is a long-living, benthic burrowing species with low growth and mortality rates, while P. longirostris is an epibenthic, short-living species characterized by higher rates of growth and mortality.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0214-8358 ISBN Médium
Région Expédition Conférence
Notes WOS:000504829900006 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2710
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Auteur Dambrine, C.; Huret, M.; Woillez, M.; Pecquerie, L.; Allal, F.; Servili, A.; de Pontual, H.
Titre Contribution of a bioenergetics model to investigate the growth and survival of European seabass in the Bay of Biscay – English Channel area Type Article scientifique
Année 2020 Publication (down) Revue Abrégée Ecological Modelling
Volume 423 Numéro Pages 109007
Mots-Clés Dynamic Energy Budget theory; Early-life stages; Growth, Starvation; Northeast Atlantic
Résumé The European seabass (Dicentrarchus labrax) is a species of particular ecological and economic importance. Stock assessments have recently revealed the worrying state of the “Northern stock”, probably due to overfishing and a series of poor recruitments. The extent to which these poor recruitments are due to environmental variability is difficult to assess, as the processes driving the seabass life cycle are poorly known. Here we investigate how food availability and temperature may affect the growth and survival of wild seabass at the individual scale. To this end, we developed a bioenergetics model based on the Dynamic Energy Budget (DEB) theory. We applied it to seabass population of the Northeast Atlantic region (Bay of Biscay – English Channel area) throughout their entire life cycle. We calibrated the model using a combination of age-related length and weight datasets: two were from aquaculture experiments (larvae and juveniles raised at 15 and 20°C) and one from a wild population (juveniles and adults collected during surveys or fish market sampling). By calibrating the scaled functional response that rules the ingestion of food and using average temperature conditions experienced by wild seabass (obtained from tagged individuals), the model was able to reproduce the duration of the different stages, the growth of the individuals, the number of batches and their survival to starvation. We also captured one of the major differences encountered in the life traits of the species: farmed fish mature earlier than wild fish (3 to 4 years old vs. 6 years old on average for females, respectively) probably due to better feeding conditions and higher temperature. We explored the growth and survival of larvae and juveniles by exposing the individuals to varying temperatures and food levels (including total starvation). We show that early life stages of seabass have a strong capacity to deal with food deprivation: the model estimated that first feeding larvae could survive 17 days at 15°C. We also tested individual variability by adjusting the specific maximum assimilation rate and found that larvae and juveniles with higher assimilation capacity better survived low food levels at a higher temperature. We discuss our results in the context of the recent years of poor recruitment faced by European seabass.
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Volume de collection Numéro de collection Edition
ISSN 0304-3800 ISBN Médium
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Notes WOS:000525397200005 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2724
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Auteur Benazzouz, A.; Pelegri, J.L.; Demarcq, H.; Machin, F.; Mason, E.; Orbi, A.; Pena-Izquierdo, J.; Soumia, M.
Titre On the temporal memory of coastal upwelling off NW Africa Type Article scientifique
Année 2014 Publication (down) Revue Abrégée J. Geophys. Res.-Oceans
Volume 119 Numéro 9 Pages 6356-6380
Mots-Clés atlantic; Canary Current; cape blanc region; circulation; Coastal upwelling; eastern boundary; Ekman transport; interannual variability; northwest africa; NW Africa; sea-surface temperature; SST difference; system; temporal memory; water
Résumé We use a combination of satellite, in situ, and numerical data to provide a comprehensive view of the seasonal coastal upwelling cycle off NW Africa in terms of both wind forcing and sea surface temperature (SST) response. Wind forcing is expressed in terms of both instantaneous (local) and time-integrated (nonlocal) indices, and the ocean response is expressed as the SST difference between coastal and offshore waters. The classical local index, the cross-shore Ekman transport, reproduces reasonably well the time-latitude distribution of SST differences but with significant time lags at latitudes higher than Cape Blanc. Two nonlocal indices are examined. One of them, a cumulative index calculated as the backward averaged Ekman transport that provides the highest correlation with SST differences, reproduces well the timing of the SST differences at all latitudes (except near Cape Blanc). The corresponding time lags are close to zero south of Cape Blanc and range between 2 and 4 months at latitudes between Cape Blanc and the southern Gulf of Cadiz. The results are interpreted based on calculations of spatial and temporal auto and cross correlations for wind forcing and SST differences. At temporal scales of 2-3 weeks, the alongshore advection of alongshore momentum compensates for interfacial friction, allowing the upwelling jet and associated frontal system to remain active. We conclude that the coastal jet plays a key role in maintaining the structure of coastal upwelling, even at times of relaxed winds, by introducing a seasonal memory to the system in accordance with the atmospheric-forcing annual cycle.
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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 2169-9275 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1194
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