A multimetric-index approach using fisheries data to assess fish assemblage structure in relation to salinity gradient in a tropical West African estuary
| Autor: | Jean-Marc Ecoutin, Raymond Laë, Omar Thiom Thiaw, L. Tito de Morais, Justin Kantoussan |
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| Přispěvatelé: | Université Gaston Berger de Saint-Louis Sénégal (UGB), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
biological indicators Casamance Estuary ecosystem monitoring fishery statistics inverse hypersaline estuary Senegal taxonomic diversity 010504 meteorology & atmospheric sciences Fish farming inverse hypersaline estuary ecosystem monitoring Aquatic Science fishery statistics 01 natural sciences Food chain fishery 14. Life underwater taxonomic diversity 1 SUD Ecology Evolution Behavior and Systematics 0105 earth and related environmental sciences Trophic level Apex predator geography geography.geographical_feature_category 010604 marine biology & hydrobiology ACL Estuary Euryhaline Catch per unit effort biological indicators Senegal taxonomic diversity Salinity Fishery Casamance Estuary statistics Environmental science [SDE.BE]Environmental Sciences/Biodiversity and Ecology |
| Zdroj: | African Journal of Marine Science African Journal of Marine Science, NISC, 2018, 40 (2), pp.175-185. ⟨10.2989/1814232X.2018.1474802⟩ African Journal of Marine Science, 2018, 40 (2), pp.175-185. ⟨10.2989/1814232X.2018.1474802⟩ African Journal Of Marine Science (1814-232X) (Natl Inquiry Services Centre Pty Ltd), 2018, Vol. 40, N. 2, P. 175-185 African Journal of Marine Science; Vol 40, No 2 (2018); 175-185 |
| ISSN: | 1814-232X 1814-2338 |
| Popis: | This study examines the effects of increasing salinity on fish assemblage structure in the Casamance Estuary, Senegal, using a series of indices. The study data were derived from commercial fishery surveys conducted between April and July 2005. Analysis of within-trophic-group diversity in the Casamance Estuary shows a significant drop in the diversity of apex predators in the upper, more saline reaches of the estuary. By contrast, primary consumers adapted well to salinity changes and exhibited higher taxonomic diversity in the upper reaches of the estuary than in the lower reaches. The findings also indicate decreases in average sizes of the landed species and the trophic levels among fish catches in the direction of the upper reaches. However, the catch per unit effort (CPUE) was globally higher in the upstream area of the estuary as compared with the downstream area. This increasing CPUE trend from the lower towards the upper reaches is attributed to (i) the high primary productivity in the upper Casamance Estuary; (ii) the increasing abundance of euryhaline fish species in an upstream direction; and (iii) ‘telescoping’ of the food chain through the presence of mostly herbivorous fishes in the upper reaches. Such a situation likely facilitated high fish production in the upstream area of the estuary, though multimetric indices indicated unfavourable living conditions for many fish taxa in this area. Keywords : biological indicators, Casamance Estuary, ecosystem monitoring, fishery statistics, inverse hypersaline estuary, Senegal, taxonomic diversity |
| Databáze: | OpenAIRE |
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