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Auteur Meynard, C.N.; Kaplan, D.M.; Leroy, B.
Titre Detecting outliers in species distribution data: Some caveats and clarifications on a virtual species study Type Article scientifique
Année 2019 Publication (up) Revue Abrégée J. Biogeogr.
Volume 46 Numéro 9 Pages 2141-2144
Mots-Clés enm; observation errors; outliers; prevalence; probabilistic approach; sample bias; simulations; species distribution models; thresholds; virtual ecology; virtual species
Résumé Liu et al. (2018) used a virtual species approach to test the effects of outliers on species distribution models. In their simulations, they applied a threshold value over the simulated suitabilities to generate the species distributions, suggesting that using a probabilistic simulation approach would have been more complex and yield the same results. Here, we argue that using a probabilistic approach is not necessarily more complex and may significantly change results. Although the threshold approach may be justified under limited circumstances, the probabilistic approach has multiple advantages. First, it is in line with ecological theory, which largely assumes non-threshold responses. Second, it is more general, as it includes the threshold as a limiting case. Third, it allows a better separation of the relevant intervening factors that influence model performance. Therefore, we argue that the probabilistic simulation approach should be used as a general standard in virtual species studies.
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Langue English Langue du Résumé Titre Original
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ISSN 0305-0270 ISBN Médium
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Notes WOS:000483602900019 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2640
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Auteur Moullec, F.; Velez, L.; Verley, P.; Barrier, N.; Ulses, C.; Carbonara, P.; Esteban, A.; Follesa, C.; Gristina, M.; Jadaud, A.; Ligas, A.; Díaz, E.L.; Maiorano, P.; Peristeraki, P.; Spedicato, M.T.; Thasitis, I.; Valls, M.; Guilhaumon, F.; Shin, Y.-J.
Titre Capturing the big picture of Mediterranean marine biodiversity with an end-to-end model of climate and fishing impacts Type Article scientifique
Année 2019 Publication (up) Revue Abrégée Progress in Oceanography
Volume 178 Numéro Pages 102179
Mots-Clés Ecosystem model; Ecosystem Approach to Fisheries Management; Eco3M-S model; Global change; NEMOMED model; OSMOSE model
Résumé The Mediterranean Sea is one of the main hotspots of marine biodiversity in the world. The combined pressures of fishing activity and climate change have also made it a hotspot of global change amidst increasing concern about the worsening status of exploited marine species. To anticipate the impacts of global changes in the Mediterranean Sea, more integrated modelling approaches are needed, which can then help policymakers prioritize management actions and formulate strategies to mitigate impacts and adapt to changes. The aim of this study was to develop a holistic model of marine biodiversity in the Mediterranean Sea with an explicit representation of the spatial, multispecies dynamics of exploited resources subject to the combined influence of climate variability and fishing pressure. To this end, we used the individual-based OSMOSE model (Object-oriented Simulator of Marine ecOSystEms), including 100 marine species (fish, cephalopods and crustaceans) representing about 95% of the total declared catch, at a high spatial resolution (400 km2) and a large spatial scale (the entire Mediterranean basin) – the first time such a resolution and scale have been modelled. We then combined OSMOSE with the NEMOMED 12 physical model and the Eco3M-S biogeochemical low trophic level model to build the end-to-end model, OSMOSE-MED. We fitted OSMOSE-MED model with observed or estimated biomass and commercial catch data using a likelihood approach and an evolutionary optimization algorithm. The outputs of OSMOSE-MED were then verified against observed biomass and catch data, and compared with independent datasets (MEDITS data, diet composition and trophic levels). The model results – at different hierarchical levels, from individuals to the scale of the ecosystem – were consistent with current knowledge of the structure, functioning and dynamics of the ecosystems in the Mediterranean Sea. While the model could be further improved in future iterations, all the modelling steps – the comprehensive representation of key ecological processes and feedback, the selective parameterization of the model, and the comparison with observed data in the validation process – strengthened the predictive performance of OSMOSE-MED and thus its relevance as an impact model to explore the future of marine biodiversity under scenarios of global change. It is a promising tool to support ecosystem-based fishery management in the Mediterranean Sea.
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Volume de collection Numéro de collection Edition
ISSN 0079-6611 ISBN Médium
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Notes WOS:000496861900020 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2667
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Auteur Hill, S.L.; Hinke, J.; Bertrand, S.; Fritz, L.; Furness, R.W.; Ianelli, J.N.; Murphy, M.; Oliveros‐Ramos, R.; Pichegru, L.; Sharp, R.; Stillman, R.A.; Wright, P.J.; Ratcliffe, N.
Titre Reference points for predators will progress ecosystem-based management of fisheries Type Article scientifique
Année 2020 Publication (up) Revue Abrégée Fish and Fisheries
Volume 21 Numéro 2 Pages 368-378
Mots-Clés adaptive management; Aichi Biodiversity Targets; ecosystem interactions; indirect impacts; management strategy; precautionary approach
Résumé Ecosystem-based management of fisheries aims to allow sustainable use of fished stocks while keeping impacts upon ecosystems within safe ecological limits. Both the FAO Code of Conduct for Responsible Fisheries and the Aichi Biodiversity Targets promote these aims. We evaluate implementation of ecosystem-based management in six case-study fisheries in which potential indirect impacts upon bird or mammal predators of fished stocks are well publicized and well studied. In particular, we consider the components needed to enable management strategies to respond to information from predator monitoring. Although such information is available in all case-studies, only one has a reference point defining safe ecological limits for predators and none has a method to adjust fishing activities in response to estimates of the state of the predator population. Reference points for predators have been developed outside the fisheries management context, but adoption by fisheries managers is hindered a lack of clarity about management objectives and uncertainty about how fishing affects predator dynamics. This also hinders the development of adjustment methods because these generally require information on the state of ecosystem variables relative to reference points. Nonetheless, most of the case-studies include precautionary measures to limit impacts on predators. These measures are not used tactically and therefore risk excessive restrictions on sustainable use. Adoption of predator reference points to inform tactical adjustment of precautionary measures would be an appropriate next step towards ecosystem-based management.
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Volume de collection Numéro de collection Edition
ISSN 1467-2979 ISBN Médium
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Notes WOS:000505754400001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2684
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Auteur Lezama-Ochoa, N.; Murua, H.; Chust, G.; Ruiz, J.; Chavance, P.; Molina, A.D. de; Caballero, A.; Sancristobal, I.
Titre Biodiversity in the by-catch communities of the pelagic ecosystem in the Western Indian Ocean Type Article scientifique
Année 2015 Publication (up) Revue Abrégée Biodivers Conserv
Volume 24 Numéro 11 Pages 2647-2671
Mots-Clés By-catch; Diversity; Ecosystem Approach to Fisheries Management; Evolutionary Biology; Plant Sciences; Purse seine fishery; Tree Biology; Western Indian Ocean
Résumé Diversity in the by-catch communities from the pelagic ecosystem in the tropical tuna purse seine fishery has been poorly studied. This study uses different biodiversity measures to compare drifting fish aggregating devices (FADs) and Free School sets (sets made on schools of tuna) of the Western Indian Ocean. Data was collected from observer programs carried out by the European Union between 2003 and 2010 on board Spanish and French fleets. Alpha (species diversity of a particular area) and Beta diversity (difference in species composition between different areas) was analyzed to assess differences in the number of species, abundances and the species composition between areas and fishing modes. Generalized additive models were undertaken to explore which geographical/environmental variables explain the distribution of species richness index and Shannon diversity index in both fishing modes. Results showed that by-catch species in FAD communities may be used as observatories of surface pelagic biodiversity in combination with Free School communities. FAD communities were more diverse with higher number of species (74 species) and evenly distributed than Free School communities (56 species). However, environmental variables played a more important role in Free School communities. Somalia area and Mozambique Channel were the areas with highest biodiversity rates in both fishing modes. This work contributed for the future implementation of the EAFM to manage the pelagic ecosystem in a holistic and more integrated way.
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Volume de collection Numéro de collection Edition
ISSN 0960-3115, 1572-9710 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1422
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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 (up) 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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Editeur Lieu de Publication Éditeur
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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