Comparative review of entanglement risk assessments for cetacean conservation and management

Cetacean entanglement in fishing gear remains a major global threat that exposes persistent gaps in how fisheries management frameworks manage risk to nontarget species. Ecological risk assessment (ERA) offers a structured way to link exposure and consequences to an explicit statement of risk, but entanglement risk assessments vary widely in form and function, making them challenging to synthesize and put into practice. We reviewed 59 studies that assessed cetacean entanglement risk and organized them based on the three core ERA components: problem formulation, analysis (exposure and consequences), and risk characterization. Across regions, approaches ranged from spatial-temporal overlap models and encounter-rate analyses to expert-based qualitative scoring, reflecting differences in data availability, species biology, and fishery context. Exposure was evaluated in 95% of studies, consequence analysis appeared in 76% of assessments, and risk was fully or partially characterized by 92% of studies, sometimes relative to thresholds for mortality or population decline. About one-third (35%) included objectives related to management evaluation, such as considering risk-reduction from gear modifications and time-area closures. Overall, we found that uptake would improve with more consistent reporting and explicit links to decision pathways. Clearer articulation of endpoints, study scope, and underlying assumptions, alongside more transparent treatment of uncertainty and data limitations, would make assessments easier to interpret and compare. Building in validation and planning for periodic updates would further strengthen confidence and support defensible management action. Closing the gap between entanglement risk assessment and implementation is key to sustaining cetaceans and fisheries.