Fishery bycatch rates largely driven by variation in individual vessel behaviour

Fisheries bycatch continues to drive the decline of many threatened marine species such as marine mammals, seabirds, sea turtles and sharks. Management frameworks typically address non-target catch with fleet-level controls on fishing. Yet, individual operators differ in their fishing practices and efficiency at catching fish. If operators have differing abilities to target, they should also have differing abilities to avoid bycatch. To evaluate the generality of this pattern, we analysed variations in threatened species bycatch among individual operators from five industrial fisheries in Australia representing different geographic areas, gear types and target species. The individual vessel is a significant predictor of interaction rates in all 15 cases, including species that represent high or low costs to fishers, or have economic value. Encouragingly, we found high-target and low-bycatch vessels in all five fisheries, including gears often perceived as indiscriminate in the species they catch. The patterns of variation we find in the Australian fisheries data highlight the potential to reduce bycatch using measures focused on specific performance groups of individuals, offering an alternative approach that can complement fleet-wide controls.