Assessing Data Requirements for Calculating Sustainable Marine Mammal Bycatch Limits

The Fish and Fish Product Import Provisions of the Marine Mammal Protection Act extend several domestic marine mammal management tools to foreign fisheries wishing to export their products to the United States. One of these tools is the calculation of bycatch limits for marine mammal populations impacted by fishing operations. Several methods exist for these calculations, with the most ubiquitous methodology being the Potential Biological Removal model. This study explores all calculation methods and their data requirements, categorizing methods based on model structure and input data. Measures and concepts of population size are most crucial to creating bycatch limit models across existing methods. Exporting fishery managers in low-data environments should focus on collecting population abundance data while being mindful of other important factors such as data uncertainties, how models fit into larger regulatory schemes, and conservation objectives. Further, these models are most accurate and impactful when they are updated and grown as more data about marine mammal populations are collected. Data availability is the primary limiting factor in implementing bycatch limit methods, and this work has important implications for comparability determinations for foreign fisheries under the new Import Provisions.