Shark mortality cannot be assessed by fishery overlap alone
Available here as IOTC-2021-WPEB17(AS)-INF05
Many shark species worldwide are vulnerable to overexploitation due to fishing. Using only the horizontal spatial overlap between the space use of 23 satellite-tracked shark species and the fishing distribution of pelagic longline fisheries tracked using an automatic identification system, Queiroz et al.1 concluded that sharks are at high risk when sub-stantial horizontal overlap occurs. This approach to estimate fishing susceptibility, coupled with limited tag-based shark distributions to estimate fishing exposure index (FEI) hotspots, severely limits their findings and, therefore, conclusions.We challenge several assumptions made by the authors and argue that horizontal overlap alone is an unreliable indicator of susceptibility because other factors contribute considerably to catch risk, as shown