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Auteur Kirkman, S.P.; Blamey, L.; Lamont, T.; Field, J.G.; Bianchi, G.; Huggett, J.A.; Hutchings, L.; Jackson-Veitch, J.; Jarre, A.; Lett, C.; Lipinski, M.R.; Mafwila, S.W.; Pfaff, M.C.; Samaai, T.; Shannon, L.J.; Shin, Y.-J.; van der Lingen, C.D.; Yemane, D.
Titre Spatial characterisation of the Benguela ecosystem for ecosystem-based management Type Article scientifique
Année 2016 Publication Revue Abrégée Afr. J. Mar. Sci.
Volume 38 Numéro 1 Pages 7-22
Mots-Clés agulhas system; atlantic-ocean; biology; drivers; ecosystem approach to fisheries; large marine ecosystem; large marine ecosystem; marine spatial planning; models; monitoring; northern benguela; nursery areas; physical oceanography; regime shifts; sea use management; southern benguela; upwelling system; variability
Résumé The three countries of the Benguela Current Large Marine Ecosystem (BCLME), namely Angola, Namibia and South Africa, have committed to implementing ecosystem-based management (EBM) including an ecosystem approach to fisheries (EAF) in the region, to put in practice the principles of sustainable development in ocean-related matters. There is also recognition of the need for marine spatial planning (MSP) as a process for informing EBM with regard to the allocation and siting of ocean uses so that ecosystem health is ensured and trade-offs between ecosystem services are appropriately dealt with. Marine spatial planning is both an integrated and an area-based process, and this paper produces a spatial characterisation of the BCLME for achieving a common basis for MSP in the region, focusing on the oceanography, biology and fisheries. Recognising spatial variation in physical driving forces, primary and secondary production, trophic structures and species richness, four different subsystems are characterised: (1) north of the Angola-Benguela Front, (2) from the Angola-Benguela Front to Luderitz, (3) from Luderitz to Cape Agulhas, and (4) from Cape Agulhas to Port Alfred on the south-east coast of South Africa. Research and monitoring requirements of relevance for MSP and EBM in the region are identified, focusing on understanding variability and change, including with regard to the boundary areas identified for the system. To this end, 14 cross-shelf monitoring transects are proposed (including seven that are already being monitored) to estimate fluxes of biota, energy and materials within and between the subsystems. The usefulness of models for understanding ecosystem variability and changes is recognised and the need for fine-scale resolution of both sampling and modelling for adequate MSP as input to EBM for the often-conflicting interests of conserving biodiversity, and managing fisheries, recreation, offshore oil and gas exploration and exploitation, offshore mining and shipping routes, is emphasised.
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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 1814-232x ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1658
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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 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 Moullec, F.; Gascuel, D.; Bentorcha, K.; Guénette, S.; Robert, M.
Titre Trophic models: What do we learn about Celtic Sea and Bay of Biscay ecosystems? Type Article scientifique
Année 2017 Publication Revue Abrégée Journal of Marine Systems
Volume 172 Numéro Pages 104-117
Mots-Clés Bay of Biscay; celtic sea; Ecopath with Ecosim; Ecosystem Approach to Fisheries Management (EAFM); EcoTroph; Trophic indicators
Résumé Trophic models are key tools to go beyond the single-species approaches used in stock assessments to adopt a more holistic view and implement the Ecosystem Approach to Fisheries Management (EAFM). This study aims to: (i) analyse the trophic functioning of the Celtic Sea and the Bay of Biscay, (ii) investigate ecosystem changes over the 1980–2013 period and, (iii) explore the response to management measures at the food web scale. Ecopath models were built for each ecosystem for years 1980 and 2013, and Ecosim models were fitted to time series data of biomass and catches. EcoTroph diagnosis showed that in both ecosystems, fishing pressure focuses on high trophic levels (TLs) and, to a lesser extent, on intermediate TLs. However, the interplay between local environmental conditions, species composition and ecosystem functioning could explain the different responses to fisheries management observed between these two contiguous ecosystems. Indeed, over the study period, the ecosystem's exploitation status has improved in the Bay of Biscay but not in the Celtic Sea. This improvement does not seem to be sufficient to achieve the objectives of an EAFM, as high trophic levels were still overexploited in 2013 and simulations conducted with Ecosim in the Bay of Biscay indicate that at current fishing effort the biomass will not be rebuilt by 2030. The ecosystem's response to a reduction in fishing mortality depends on which trophic levels receive protection. Reducing fishing mortality on pelagic fish, instead of on demersal fish, appears more efficient at maximising catch and total biomass and at conserving both top-predator and intermediate TLs. Such advice-oriented trophic models should be used on a regular basis to monitor the health status of marine food webs and analyse the trade-offs between multiple objectives in an ecosystem-based fisheries management context.
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Langue Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0924-7963 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2093
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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 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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Langue Langue du Résumé Titre Original
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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 Pennino, M.G.; Bellido, J.M.; Conesa, D.; Coll, M.; Tortosa-Ausina, E.
Titre The analysis of convergence in ecological indicators: An application to the Mediterranean fisheries Type Article scientifique
Année 2017 Publication Revue Abrégée Ecological Indicators
Volume 78 Numéro Supplement C Pages 449-457
Mots-Clés Convergence analysis; ecological indicators; Ecosystem Approach to Fisheries Management; Mediterranean Sea; Non-parametric density estimation; Transition probability matrix
Résumé Ecological indicators are increasingly used to examine the evolution of natural ecosystems and the impacts of human activities. Assessing their trends to develop comparative analyses is essential. We introduce the analysis of convergence, a novel approach to evaluate the dynamic and trends of ecological indicators and predict their behavior in the long-term. Specifically, we use a non-parametric estimation of Gaussian kernel density functions and transition probability matrix integrated in the R software. We validate the performance of our methodology through a practical application to three different ecological indicators to study whether Mediterranean countries converge towards similar fisheries practices. We focus on how distributions evolve over time for the Marine Trophic Index, the Fishing in Balance Index and the Expansion Factor during 1950–2010. Results show that Mediterranean countries persist in their fishery behaviors throughout the time series, although a tendency towards similar negative effects on the ecosystem is apparent in the long-term. This methodology can be easily reproduced with different indicators and/or ecosystems in order to analyze ecosystem dynamics.
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Volume de collection Numéro de collection Edition
ISSN 1470-160x ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2226
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