Spring zooplankton distribution in the Bay of Biscay from 1998 to 2006 in relation with anchovy recruitment

Abstract

The objective of this study was to investigate whether successive recruitment failures in the anchovy fishery in the Bay of Biscay were due to changes in the zooplankton biomass or composition. Image analysis and automatic recognition were used to analyse zooplankton samples collected during diel egg production method spring surveys from 1998 to 2006. We were not able to detect any trend in zooplankton biomass during this period. The zooplankton spatial distribution showed permanent features with large organisms being more abundant over the shelf break and outer areas. Finally, we found a negative correlation between anchovy recruitment and zooplankton biomass which suggests that the 2002–2006 failures in anchovy recruitment in the Bay of Biscay are not due to a decrease in mesozooplankton biomass.