Characterizing catches taken by different gears as a step towards evaluating fishing pressure on fish communities

To implement an ecosystem approach to fisheries management, there is a need to characterize the total pressure exerted by fisheries at the community level. French onboard observer data were used to derive catch metrics and compare fishing distribution across community components between two sites in the Southern Bay of Biscay. Sample-based rarefaction curves were used to standardize metrics across different active and passive gears, and correct for sample size differences. Six metrics for species, length and functional catch composition were tested. Length and functional metrics were found the most relevant metrics to highlight differences in catches between gears, sites, and gear-site interactions. Significant differences were found between gears, mainly in mean length and proportion of piscivores. None of the gears had the most diverse catch across all metrics. Small differences were found between sites, mainly in length range and species richness.