Biomass and Length Distribution for Atlantic Cod, Thorny Skate and White Hake from the Surveys Conducted by Spain in NAFO Divisions 3NO
Data for Atlantic cod (Gadus morhua), Thorny skate (Amblyraja radiata) and Withe hake (Urophycis tenuis) from Spanish Spring survey are presented. The survey vessel changed in 2001, from the C/V Playa de Menduíña to the R/V Vizconde de Eza, so, in order to maintain the historical series, we transfor...
Main Authors: | , |
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Format: | Report |
Language: | English |
Published: |
2005
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Subjects: | |
Online Access: | http://hdl.handle.net/10508/598 http://hdl.handle.net/10261/328644 |
Summary: | Data for Atlantic cod (Gadus morhua), Thorny skate (Amblyraja radiata) and Withe hake (Urophycis tenuis) from Spanish Spring survey are presented. The survey vessel changed in 2001, from the C/V Playa de Menduíña to the R/V Vizconde de Eza, so, in order to maintain the historical series, we transformed the data for Atlantic cod and Thorny skate until that year. 1997-2000 data are transformed data from the C/V Playa de Menduíña and 2002-2004 data are original data from R/V Vizconde de Eza. In 2001, there are data from the two vessels for the three species. The abundance and biomass were estimated for the period 1997-2004 for Atlantic cod and Thorny skate, and 2001-2004 for White hake. The length distribution was obtained and presented in numbers per haul stratified mean catches. For Atlantic cod, we can see a decreasing of the biomass since the year 2002, and it remains in a very low level. For this species, a good recruitment can be seen this year. Thorny skate indices decreased since 2001 until 2003 and increase last year, reaching the second higher value of the series. For White hake, there were great catches 2001, and a sharp decreasing since then. In 2004 we can see a presence of individuals between 16 and 26 cm |
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