Ecosystem-based harvest strategies in regional fisheries management

Eric Gilman , Nathan Taylor, Milani Chaloupka, Mariano Koen-Alonso, François Poisson, Cheng Zhou

Fisheries have complex effects on the dynamics and structure of marine ecosystems. Single-stock management in isolation can cause ecosystems to deviate from desired states and fail to achieve both single-stock and ecosystem-wide objectives. This can be addressed through ecosystem-based fisheries management (EBFM), including ecosystem harvest strategies. We benchmarked the state of development of core components of ecosystem harvest strategies. We assessed the development and implementation of ecosystem state indicators, their application in defining limit and target reference points for ecosystem overfishing, the assessment of the predicted performance and tradeoffs of alternative ecosystem management procedures such as through management strategy evaluation, and the use of ecosystem thresholds to guide or trigger ecosystem management procedures. Across 22 intergovernmental bodies with mandates to adopt binding fisheries management measures, implementation of these components is limited. Two are at relatively more advanced stages involving the exploration or adoption of ecosystem thresholds and management procedures, while seven are at incipient stages focused primarily on the development or exploratory use of ecosystem indicators. The latter group includes all tropical tuna regional fisheries management organizations, which have coordinated activities to integrate ecosystem considerations into fisheries management processes but have not progressed to operational ecosystem harvest strategies. Approaches by the few intergovernmental bodies that have progressed the most serve as a model for organizations at incipient stages. Our findings benchmark the state of progress in transitioning to ecosystem harvest strategies, one key component of EBFM, and highlight priorities for mainstreaming ecosystem considerations in regional fisheries management.