| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
A multimetric-index approach using fisheries data to assess fish assemblage structure in relation to salinity gradient in a tropical West African estuary
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| Autores: |
Kantoussan, J.
Ecoutin, J. M.
Lae, R.
Thiaw, O. T.
Tito De Morais, L.
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| Data: |
2018
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| Ano: |
2018
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| Palavras-chave: |
Biological indicators
Casamance Estuary
Ecosystem monitoring
Fishery statistics
Inverse hypersaline estuary
Senegal
Taxonomic diversity
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| Resumo: |
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.
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
https://archimer.ifremer.fr/doc/00451/56222/57945.pdf
DOI:10.2989/1814232X.2018.1474802
https://archimer.ifremer.fr/doc/00451/56222/
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| Editor: |
Natl Inquiry Services Centre Pty Ltd
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| Formato: |
application/pdf
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| Fonte: |
African Journal Of Marine Science (1814-232X) (Natl Inquiry Services Centre Pty Ltd), 2018 , Vol. 40 , N. 2 , P. 175-185
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| Direitos: |
NISC (Pty) Ltd
info:eu-repo/semantics/openAccess
restricted use
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