Toward true FAD deployment limits in the t-RFMOs

All four tropical tuna RFMOs (t-RFMOs) have adopted provisions related to the proliferation of fish aggregating devices (FADs) in use by purse seine operations. Addressing the growing numbers of FADs in use has been a challenge for the t-RFMOs, as a review of the existing measures shows they are not restrictive at the fleet level and would allow a considerable number of purse seine operators to increase their FAD use. The need to consider development of science-based limits on the deployment of the devices was a key conclusion of scientists at the 2017 Global FAD Science Symposium as well as participants at the 1st Meeting of the Joint t-RFMO FAD Working Group that same year. To transition those provisions to true limits, the t-RFMOs should develop management objectives that clearly identify their goals for impacted fisheries. We offer options for management objectives including avoiding adverse impacts to tropical tuna populations (via a proxy measurement of catch-per-unit-of-effort of purse seine operations) and limiting impacts to habitat from FADs that become marine debris.