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| Registros recuperados: 188 | |
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| Daget, J.. |
| The author explains that the population dynamics study, descriptive and explicative way, the changes which happen in the structure and the parameters (growth rate, sex ratio, fecundity, mortality etc.) of a monospecific population, by the use of mathematical models which permit prediction and simulation. If the fish population is not exploited, it is necessary to sample it directly and obtain samples representative of the demographical structure by experimental fishing (like electrical fishing) or by selectivity corrections. If the population is exploited, often the exploited phasis of the stock is only studied from samples representative of the whole captures. Now it happens that there is an important difference between the demographical structure of the... |
| Tipo: Text |
Palavras-chave: Pisces; Catch statistics; Mathematical models; Population dynamics. |
| Ano: 1976 |
URL: http://archimer.ifremer.fr/doc/1976/publication-1999.pdf |
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| Junquera, Susana. |
| Using the fishing records from the most relevant ports of the Cantabrian and Galician coasts, th history of the anchovy (Engraulis encrasicholus ) fishery in this area is reconstituted. The crisis observed and the variations in the fishing areas throughout the time are analyzed. An estimation of the age classes composition in the catches founded on commercial classification data can be made. The hypothesis of existence of a core population in the Southern part of the Bay of Biscay is presented and that only under certain advantageous condition the expansion of this species throughout all the Cantabrian Sea was possible. |
| Tipo: Text |
Palavras-chave: Pisces; Age composition; Population dynamics; Catch/effort; Fishery statistics. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/publication-1795.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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| 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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| Registros recuperados: 188 | |
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