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Vigneau, Joel; Mahevas, Stephanie. |
Measuring fish on board fishing vessels or at fish markets to collect data for stock assessment purposes is one of the most straightforward actions carried out by fisheries scientists worldwide. However, such samples are not straightforward to handle and analyse because of their vector-type structure. A generic tool that allows investigation in any multinomial-like sampling scheme is provided, as long as the scheme is built on a ratio estimator, which is the case for most length sampling in the fisheries sector. The use of this tool is discussed using data obtained from two different sampling designs, one consisting of commercial market samples by category and the other on fishing activity or metier. The identification of outliers, misallocated samples, or... |
Tipo: Text |
Palavras-chave: Stratification; Sampling design; Market sampling; Length structure. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2731.pdf |
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Vigneau, Joel; Mahevas, Stephanie. |
Measuring fish on a market or on board a vessel is the most common action taken by biologists all around the world to gather data for stock assessment. The samples coming from this kind of survey are of vector type and are not straightforward to analyse and compare. This paper proposes a generic tool that enables to investigate in any multinomial like sampling scheme. The use of this tool will be discussed based on examples from two different sampling designs. One is a sampling of commercial market categories and the other is a métier based sampling. The research of outliers, misallocated samples or potential bias, the stratification and the analysis of within and between strata variance will be discussed with the objective of constructing the best... |
Tipo: Text |
Palavras-chave: Stratification; Sampling design; Length structure; Market sampling. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-2698.pdf |
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Fávaro,Luís Fernando; Oliveira,Elton Celton de; Ventura,Augusto de Oliveira Brunow; Verani,Nelsy Fenerich. |
The spatial and temporal distribution of Sphoeroides greeleyi and Sphoeroides testudineus were established from collections (biological material and environmental data) conducted on a monthly basis from May 2000 to April 2001 in intertidal areas along the north-south axis of the estuarine complex of Paranaguá, Paraná State. In addition to characterizing a north-south spatial gradient, which fluctuates seasonally, the variation in the abiotic factors made possible the division of the estuary into three regions: north, central and south. Spatially, it was found that the number of individuals declines significantly for both species in the north-south direction of the estuary. Moreover, significant differences were found in the size of individuals across the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tetraodontidae; Estuarine-residents; Closely related species; Abundance; Length structure. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252009000200020 |
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