Advances in Gillnetting on Both Sides of Atlantic

In Europe and North America, gillnetting has been recently standardized by European Committee for Standardization (2005) and American Fisheries Society (2009). Among passive techniques, gillnets are one of the most important gears. European gillnetting standard is based on depth stratified, spatial random sampling with benthic gillnets (1.5 x 30 m), supplemented by pelagic gillnets (≥1.5 x 30 m). Both gillnets have 12 mesh sizes ranging from 5-55 mm (bar mesh). American gillnetting standard is based on benthic gillnets (1.8 x 24.8 m with eight mesh sizes 19-64 mm bar mesh) with spatially randomized sampling. Effort for both standards is determined by size of sampled waterbody and the minimum precision desired (50% difference between sampling occasions for the European, left to biologist’s discretion for the American standard). A revised European standard is expected to be published during 2015. The new version reflects recent findings related to gillnet size selectivity and species selectivity, effects of fish activity and gillnet exposure on gillnet catch, saturation and dependence of gillnet catch on fish density, mechanisms of gillnet capture (i.e., fish escapement after being temporarily enmeshed), and proper sampling design. American standard is not presently under revision, but current research is quantifying size selectivity.