Atlantic Cod and Yellowtail Flounder Indices from the Spanish Survey Conducted in Divisions 3NO of the NAFO Regulatory Area
Since 1995, Spain carries out a stratified random spring bottom trawl survey in Divisions 3NO of the NAFO Regulatory Area. In 2001, the trawl vessel and gear were replaced; so, the time series indices were transformed. The transformed entire series of mean catches, biomass and length distribution fo...
Main Authors: | , , , |
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Format: | Report |
Language: | English |
Published: |
2006
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Subjects: | |
Online Access: | http://hdl.handle.net/10508/603 http://hdl.handle.net/10261/328640 |
Summary: | Since 1995, Spain carries out a stratified random spring bottom trawl survey in Divisions 3NO of the NAFO Regulatory Area. In 2001, the trawl vessel and gear were replaced; so, the time series indices were transformed. The transformed entire series of mean catches, biomass and length distribution for Atlantic cod (Gadus morhua) are presented for the period 1997-2000 and for Yellowtail flounder (Limanda ferruginea) for the period 1995-2000, and the both species no-transformed data for the years 2002-2005. For 2001, there are data from the two vessels. This year the data were updated, so a new calibration was made. The changes affect the species length distribution. For Atlantic cod and yellowtail flounder there are no significant changes, both numbers and trend of the stocks. For Atlantic cod, we can see a decreasing of the biomass since the year 2002, with a slight increasing this year but without reaching the level of 2003, and it remains in a very low level. For this species, a good recruitment can be seen in the last two years. For yellowtail flounder, this is no a clear trend since 1998; its indices are almost constant along this period. |
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