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Ducrotoy, J; Desprez, M; Elkaim, B. |
The recent collapse in the landings of cockles (Cerastoderma edule) from the Bay of Somme (France) required to investigate if a change in the environmental factors was liable for the drop of the bivalve populations. This project has led to a preliminary assessment of the situation and has been drawn up from the data collected by the Groupe d'Etude des Milieux Estuariens et Littoraux since 1978. It relies on the survey of the spatio-temporal changes of bio-facies. it is suggested that the impact of changes in sediment characteristics is important as well as competition with species as Pygospio elegans (Polychaeta). The above parameters are assessed as essential in the fluctuations of the cockle numbers but they do not explain entirely the collapse in the... |
Tipo: Text |
Palavras-chave: Landing statistics; Clam fisheries; Stock assessment; Population dynamics; Marine mollusks. |
Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/1985/publication-1784.pdf |
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Desprez, M; Ducrotoy, J; Elkaim, B. |
In this paper, the results collected since 1978 on the cockle (Cerastoderma edule) in the Bay of Somme have been recapitulated. A synthesis is brought up about causes of the bivalve population collapse which was portended as early as 1982 from the animal cinetics study. In order to back up the discussion, the main results dealing with the biology and ecology of the species are recalled in illustrated form. A review of the international literature leads to a comment upon the diagrams. A comparison with data from European estuaries tends to take climatic and oceanic disturbances into account as well as local pollution such as eutrophication which is probable on the littoral of Picardy. |
Tipo: Text |
Palavras-chave: Clam fisheries; Stock assessment; Recruitment; Population dynamics; Marine mollusks. |
Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/1985/publication-1783.pdf |
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