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Auteur Mérigot, B.; Frédou, F.L.; Viana, A.P.; Ferreira, B.P.; do Nascimento Costa Junior, E.; Beserra da Silva Júnior, C.A.; Frédou, T.
Titre Fish assemblages in tropical estuaries of northeast Brazil: A multi-component diversity approach Type Article scientifique
Année 2017 Publication Revue Abrégée Ocean & Coastal Management
Volume 143 Numéro Pages 175-183
Mots-Clés Diversity indices; Double principal coordinate analysis; ecosystem-based fisheries management; Estuaries; Fishes; monitoring; taxonomic diversity
Résumé Biodiversity in estuarine ecosystems suffers from the impact of environmental changes and human activities. This mainly involves changes in temperature, salinity, pollution, habitat degradation or loss and fishing activities. The diversity of species communities is traditionally assessed on the basis of their species richness and composition. However, there is growing interest in taking into account complementary components dealing with species differences (e.g. taxonomic relatedness). In spite of their social, ecological and economic importance, the diversity of tropical estuarine fish assemblages has rarely been monitored by means of a multi-component approach under different human pressure and environmental conditions. We analysed the diversity of exploited fish communities (both target and non-target species) sampled during scientific surveys within four estuarine complexes in the state of Pernambuco, Brazil: Itapissuma, Suape, Sirinhaém, and Rio Formoso. A total of 122 species were collected within 34 samples. Overall, diversity indices and species models fitting dominance-evenness profiles mainly revealed differences between assemblages from Itapissuma, being the largest estuary with wide areas of mangrove, and the other estuaries. While assemblages from Itapissuma generally encompassed more species and individuals than the other estuaries, species were more closely related from a taxonomic point of view. In addition, a Double Principal Coordinate Analysis (DPCoA) established a typology of assemblages, useful for management purposes, and linked to particular fish families: it highlighted differences between Itapissuma, Suape, Sirinhaém and Rio Formoso. This method combines matrices of species abundances and differences (here taxonomic distances according to the Linnean classification). It was particularly accurate with a first factorial plane explaining 73% of the total inertia, while only 17% was achieved by a traditional Principal Component Analysis (PCA). Overall, this study provides an assessment of the state of fish assemblage diversity in Pernambuco estuaries where contrasted human and environmental conditions occur. It underscores the accuracy of using a multi-component diversity approach, with a multivariate analysis that is not yet widely used, for monitoring the diversity of estuaries for ecosystem-based fisheries management purposes.
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Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection The challenge of developing policies and management strategies under changing baselines and unbounded boundaries Titre de collection Abrégé
Volume de collection 143 Numéro de collection Edition
ISSN 0964-5691 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2137
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Auteur Silva Junior, C. a. B.; Mérigot, B.; Lucena-Fredou, F.; Ferreira, B.P.; Coxey, M.S.; Rezende, S.M.; Fredou, T.
Titre Functional diversity of fish in tropical estuaries: A traits-based approach of communities in Pernambuco, Brazil Type Article scientifique
Année 2017 Publication Revue Abrégée Estuar. Coast. Shelf Sci.
Volume 198 Numéro Pages 413-420
Mots-Clés patterns; biodiversity; evolutionary; assemblages; species richness; Monitoring; marine ecosystems; quadratic entropy; Diversity indices; organization; Double principal coordinate analysis; Estuarine ecosystems; Species function; redundancy; services
Résumé Environmental changes and human activities may have strong impacts on biodiversity and ecosystem functioning. While biodiversity is traditionally based on species richness and composition, there is a growing concern to take into account functional diversity to assess and manage species communities. In spite of their economic importance, functional diversity quantified by a traits-based approach is still poorly documented in tropical estuaries. In this study, the functional diversity of fishes was investigated within four estuaries in Pernambuco state, northeast of Brazil. These areas are subject to different levels of human impact (e.g. mangrove deforestation, shrimp farming, fishing etc.) and environmental conditions. Fishes were collected during 34 scientific surveys. A total of 122 species were identified and 12 functional traits were quantified describing two main functions: food acquisition and locomotion. Fish abundance and functional dissimilarities data were combined into a multivariate analysis, the Double Principal Coordinate Analysis, to identify the functional typology of fish assemblages according to the estuary. Results showed that Itapissuma, the largest estuary with a wider mangrove forest area, differs from the other three estuaries, showing higher mean values per samples of species richness S and quadratic entropy Q. Similarly, it presented a different functional typology (the first two axes of the DPCoA account for 68.7% of total inertia, while those of a traditional PCA based solely on species abundances provided only 17.4%). Conversely, Suape, Sirinhaem, and to a lower extent Rio Formoso, showed more similarity in their diversity. This result was attributed to their predominantly marine influenced hydrological features, and similar levels of species abundances and in morphological traits. Overall, this study, combining diversity indices and a recent multivariate analysis to access species contribution to functional typology, allows to deepen diversity assessment by providing additional information regarding the functional pattern of fish assemblages. (C) 2016 Elsevier Ltd. All rights reserved.
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Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
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 0272-7714 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2247
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