An evaluation of 0-group abundance indices of Barents Sea fish stocks

Abstract

The International 0-group fish survey in the Barents Sea (1965-2002) aimed to give initial indication of the recruiting year class strengths. Since 2003 the 0-group survey has been a part of a Joint Norwegian-Russian ecosystem survey of the Barents Sea, conducted by IMR (Norway) and PINRO (Russian Federation). The electronic 0-group databases were missing some data and contained errors, therefore the databases have been quality checked and corrected for the period 1980-2006. Two separate sets of 0- group indices were re-estimated, both with and without correction for capture efficiency, using a stratified sample mean approach, and 0-group indices were correlated with other appropriate abundance indices. The exclusion of errors from the database has improved our confidence in the indices and analysis. In general, the 0-group indices seem to be reliable predictors of year class strengths and are adequate to use as input in stock assessment-models and recruitment studies.