GEOGRAPHICAL VARIABILITY IN THE AMOUNT OF BIGEYE CAUGHT UNDER FADS BY PURSE SEINERS IN THE EASTERN ATLANTIC: FROM THE MULTISPECIES SAMPLES AND THE ICCAT STATISTICS
This paper analyses the geographical distribution of bigeye FAD catches by PS using results of multispecies sampling of EU FAD catches (1991-2016). This analysis shows marked geographical gradients in the geographical distribution of bigeye catches, catches being rare in coastal areas and increasing...
| Autores: | , |
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| Formato: | artículo |
| Fecha de publicación: | 2019 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/325217 |
| Acesso em linha: | http://hdl.handle.net/10261/325217 |
| Access Level: | acceso abierto |
| Palavra-chave: | Bigeye Pesquerías Centro Oceanográfico de Canarias Geographical distribution Habitat Spatial variation Temporal distribution Coastal fisheries High seas fisheries Floating structure Multispecies fishery Purse seine Fishery management |
| Resumo: | This paper analyses the geographical distribution of bigeye FAD catches by PS using results of multispecies sampling of EU FAD catches (1991-2016). This analysis shows marked geographical gradients in the geographical distribution of bigeye catches, catches being rare in coastal areas and increasingly abundant at increasing distances from the shore. Opposite changes are observed for yellowfin abundance, while skipjack abundance tends to be similar in most areas. Yearly trends in relative abundances of bigeye and skipjack are also observed. These observed species compositions are widely in contradiction with the species composition of Task II data. This statistical problem in the bigeye geographical distribution is a source of errors in the choice and analysis of FAD moratoria. It is also a source of potential error in the Task 1 bigeye catches. Based on fine scale sampled catches, bigeye catches by the Ghanaian fleet could be widely overestimated today because of its improper data processing. Our study makes the recommendation that improved Task II statistics should be prepared for the EU&al PS and for the Ghanaian fleet before the bigeye stock assessment. |
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