|   | 
Détails
   web
Enregistrements
Auteur Coll, M.; Shannon, L.J.; Kleisner, K.M.; Juan-Jordá, M.J.; Bundy, A.; Akoglu, A.G.; Banaru, D.; Boldt, J.L.; Borges, M.F.; Cook, A.; Diallo, I.; Fu, C.; Fox, C.; Gascuel, D.; Gurney, L.J.; Hattab, T.; Heymans, J.J.; Jouffre, D.; Knight, B.R.; Kucukavsar, S.; Large, S.I.; Lynam, C.; Machias, A.; Marshall, K.N.; Masski, H.; Ojaveer, H.; Piroddi, C.; Tam, J.; Thiao, D.; Thiaw, M.; Torres, M.A.; Travers-Trolet, M.; Tsagarakis, K.; Tuck, I.; van der Meeren, G.I.; Yemane, D.; Zador, S.G.; Shin, Y.-J.
Titre Ecological indicators to capture the effects of fishing on biodiversity and conservation status of marine ecosystems Type Article scientifique
Année 2016 Publication Revue Abrégée Ecological Indicators
Volume 60 Numéro Pages 947-962
Mots-Clés Biodiversity; Conservation; Ecological indicators; Fishing impacts; Marine ecosystems; Redundancy; States; Trends
Résumé IndiSeas (“Indicators for the Seas”) is a collaborative international working group that was established in 2005 to evaluate the status of exploited marine ecosystems using a suite of indicators in a comparative framework. An initial shortlist of seven ecological indicators was selected to quantify the effects of fishing on the broader ecosystem using several criteria (i.e., ecological meaning, sensitivity to fishing, data availability, management objectives and public awareness). The suite comprised: (i) the inverse coefficient of variation of total biomass of surveyed species, (ii) mean fish length in the surveyed community, (iii) mean maximum life span of surveyed fish species, (iv) proportion of predatory fish in the surveyed community, (v) proportion of under and moderately exploited stocks, (vi) total biomass of surveyed species, and (vii) mean trophic level of the landed catch. In line with the Nagoya Strategic Plan of the Convention on Biological Diversity (2011–2020), we extended this suite to emphasize the broader biodiversity and conservation risks in exploited marine ecosystems. We selected a subset of indicators from a list of empirically based candidate biodiversity indicators initially established based on ecological significance to complement the original IndiSeas indicators. The additional selected indicators were: (viii) mean intrinsic vulnerability index of the fish landed catch, (ix) proportion of non-declining exploited species in the surveyed community, (x) catch-based marine trophic index, and (xi) mean trophic level of the surveyed community. Despite the lack of data in some ecosystems, we also selected (xii) mean trophic level of the modelled community, and (xiii) proportion of discards in the fishery as extra indicators. These additional indicators were examined, along with the initial set of IndiSeas ecological indicators, to evaluate whether adding new biodiversity indicators provided useful additional information to refine our understanding of the status evaluation of 29 exploited marine ecosystems. We used state and trend analyses, and we performed correlation, redundancy and multivariate tests. Existing developments in ecosystem-based fisheries management have largely focused on exploited species. Our study, using mostly fisheries independent survey-based indicators, highlights that biodiversity and conservation-based indicators are complementary to ecological indicators of fishing pressure. Thus, they should be used to provide additional information to evaluate the overall impact of fishing on exploited marine ecosystems.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1470-160x ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1467
Lien permanent pour cet enregistrement
 

 
Auteur Loiseau, N.; Gaertner, J.-C.; Kulbicki, M.; Mérigot, B.; Legras, G.; Taquet, M.; Gaertner-Mazouni, N.
Titre Assessing the multicomponent aspect of coral fish diversity: The impact of sampling unit dimensions Type Article scientifique
Année 2016 Publication Revue Abrégée Ecological Indicators
Volume 60 Numéro Pages 815-823
Mots-Clés Evenness; Functional diversity; Index sensitivity; Sampling unit dimensions; species richness; Visual censuses
Résumé The influence of variations in sampling unit dimensions on the assessment of fish species structuring has been widely documented. However, this issue has been restricted to a very limited range of community and population indices (mainly species richness and density). Here, we have investigated this issue through the analysis of 13 diversity indices related to 3 diversity components (number of species, evenness and functional diversity). We analyzed a large set of 257 standardized underwater visual census (UVC) transects dealing with 254 coral fish species. The sensitivity of the indices to the variation in sampling unit dimensions was studied by comparing a range of 55 couples of transect length and width representing 34 sampling surfaces. We found that the extent and profile of the sensitivity to changes in transect dimensions strongly varied both from one index to another and from one dimension to another (length and width). The most sensitive indices were more strongly impacted by variation in length than width. We also showed that for a fixed transect surface, the couple of chosen length and width may alter the assessment of indices related to each of the three main diversity components studied. Some widely used diversity indices, such as species richness and Shannon index, appeared to be very sensitive to changes in transect length and width. In contrast, while still very little used in coral fish studies, two functional diversity indices (FDiv, FEve), and to a lesser extent an evenness index (Berger–Parker), remained robust in the face of change in sampling dimensions. By showing that the variation in sampling dimensions (length, width and surface) may impact diversity indices in a contrasting manner, we stress the need to take into account the sensitivity of the indices to this criterion in the process of selection of the indices to be analyzed in diversity studies. Finally, we found that 30 m long*5 m wide transects might be a suitable compromise size for assessing the patterns of each of the three major complementary components of coral fish diversity.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1470-160x ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1320
Lien permanent pour cet enregistrement
 

 
Auteur Cucherousset, J.; Villeger, S.
Titre Quantifying the multiple facets of isotopic diversity: New metrics for stable isotope ecology Type Article scientifique
Année 2015 Publication Revue Abrégée Ecological Indicators
Volume 56 Numéro Pages 152-160
Mots-Clés biodiversity; Bioindication; communities; diversity indices; food web; Populations; stable isotope analyses; Trophic diversity
Résumé Abstract

Stable isotope analyses have emerged as an insightful tool for ecologists, with quantitative methods being developed to analyse data at the population, community and food web levels. In parallel, functional ecologists have developed metrics to quantify the multiple facets of functional diversity in a n-dimensional space based on functional traits. Here, we transferred and adapted metrics developed by functional ecologists into a set of four isotopic diversity metrics (isotopic divergence, dispersion, evenness and uniqueness) complementary to the existing metrics. Specifically, these new metrics are mathematically independent of the number of organisms analysed and account for the abundance of organisms. They can also be calculated with more than two stable isotopes. In addition, we also provide a procedure for calculating the levels of isotopic overlap (similarity and turnover) between two groups of organisms. These metrics have been implemented into new functions in R made freely available to users and we illustrated their application using stable isotope values from a freshwater fish community. Transferring the framework developed initially for measuring functional diversity to stable isotope ecology will allow more efficient assessments of changes in the multiple facets of isotopic diversity following anthropogenic disturbances.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1470-160x ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 1361
Lien permanent pour cet enregistrement
 

 
Auteur Quétel, C.; Marinesque, S.; Ringler, D.; Fillinger, L.; Changeux, T.; Marteau, C.; Troussellier, M.
Titre Iles Eparses (SW Indian Ocean) as reference ecosystems for environmental research Type Article scientifique
Année 2016 Publication Revue Abrégée Acta Oecologica
Volume Numéro Pages 1-8
Mots-Clés Biodiversity sanctuaries; climate change; Environmental research; Iles Eparses; Indian Ocean; Pristine ecosystems
Résumé TAAF ensures since 2007 the management of 5 small tropical islands lying in the southwestern Indian Ocean: the Iles Eparses. These islands share an exceptional natural heritage including many marine and terrestrial endemic species. At a regional scale the Iles Eparses are some of the most pristine ecosystems, largely preserved from anthropogenic impacts due to their geographical isolation and a historically very limited human occupation. In this context, TAAF wished that Iles Eparses become unique natural laboratories for earth scientists and environmental process observation – like climate change impacts – but also sustainable biodiversity sanctuaries for which the scientific community should provide baseline ecological data to inform on appropriate conservation tools. An inter-agency research consortium emerged in 2009 to meet this commitment for the Iles Eparses. This program was intended to set a science framework in accordance with France' objectives for Research and Conservation. It enabled between 2009 and 2014 the implementation of 18 cross-disciplinary research projects ranging from geology to ecology and represented by the variety of the proposed articles in this special issue. Altogether research projects have dramatically increased knowledge on the Iles Eparses' ecosystems and have provided the first overview of their diversity, their functions and their dynamics and its determinants. In particular applied research efforts have supplied a significant amount of ecological evidence that is now available to develop optimal conservation strategy to ensure the Iles Eparses' long-term biodiversity value. These findings point out that the continuation of research activity in the Iles Eparses should be considered a priority.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Îles Éparses (French Scattered Islands, SW Indian Ocean) as reference ecosystems for environmental research. Titre de collection Abrégé
Volume de collection 72 Numéro de collection Edition
ISSN 1146-609x ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1571
Lien permanent pour cet enregistrement
 

 
Auteur Marsac, F.; Galletti, F.; Ternon, J.-F.; Romanov, E.V.; Demarcq, H.; Corbari, L.; Bouchet, P.; Roest, W.R.; Jorry, S.J.; Olu, K.; Loncke, L.; Roberts, M.J.; Ménard, F.
Titre Seamounts, plateaus and governance issues in the southwestern Indian Ocean, with emphasis on fisheries management and marine conservation, using the Walters Shoal as a case study for implementing a protection framework Type Article scientifique
Année 2019 Publication Revue Abrégée Deep Sea Research Part II: Topical Studies in Oceanography
Volume Numéro Pages 104715
Mots-Clés Amended Nairobi Convention; Areas Beyond National Jurisdiction; Benthic biodiversity; Deep-sea fisheries; Deep-sea mining; International Law of the Sea; Marine protected areas; Saya de Malha Bank; South Indian Ocean Fisheries Agreement; Vulnerable Marine Ecosystems
Résumé There is a growing interest in the management of seamounts of the Southwestern Indian Ocean (SWIO) both in waters under national jurisdictions and in the Areas Beyond National Jurisdiction (ABNJ). New scientific knowledge has been gathered through various oceanographic cruises during the past decade, and new agreements are under consideration globally to promote conservation and sustainable use of the biodiversity in the ABNJ, where the deep sea ecosystems associated with seamounts are a growing matter of concern. SWIO seamounts have attracted the interests of fishers since the 1960s, and contracts for mining exploration have been granted recently. Seamounts are known to shelter rich, fragile and poorly resilient ecosystems whose important ecological functions are threatened by various anthropogenic pressures. Whereas many seamounts and shoals are located in national waters, many others fall in the ABNJ, with no current legal status per se. To ensure conservation of their habitats and biodiversity, it is essential that protection measures are instigated under an internationally recognized legal and institutional framework. In this paper, we review the current state of such a framework relevant to seamounts, with emphasis on fisheries and conservation in the SWIO. An emblematic seamount, the Walters Shoal, is selected as a case study to discuss how it could become a fully-protected space in the ABNJ. As a large part of the SWIO is under the mandate of the Nairobi Convention (as a Regional Sea under the auspices of UNEP), guidelines are proposed to encourage dedicated seamount governance within the framework of this Convention.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue en Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0967-0645 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2689
Lien permanent pour cet enregistrement