Report of the Workshop to Review Seabird Bycatch Mitigation Measures for Hawaii’s Pelagic Longline Fisheries: September 18-19, 2018
The Western Pacific Regional Fishery Management Council, at its 173rd Meeting, directed Council staff to convene a workshop to review seabird mitigation requirements and the best scientific information available for Hawaii’s pelagic longline fisheries, considering operational aspects of the fisheries, seasonal and spatial distributions of seabird interactions, alternative bycatch mitigation measures and findings from cost-benefit analyses. To implement the Council’s directions, a Workshop to Review Seabird Bycatch Mitigation Measures for Hawaii’s Pelagic Longline Fisheries was convened at the Council office on September 18-19, 2018.
Workshop participants reviewed and discussed causes of increasing seabird catch rates and levels in the Hawaii pelagic longline fisheries. Catch levels of the black-footed albatross (Phoebastria nigripes) have been steadily increasing in the Hawaii deep-set longline fishery over the past decade, with a large spike in recent years. This significant increase was caused by a combination of increasing temporal trends in annual effort and in black-footed albatross catch rates over the time period. The rise in catch rates may have been due to variability in the temporal and spatial distribution of fishing effort, a unique captain effect (i.e., seabird catch rates are significantly explained by which person is the captain), an increase in the number of albatrosses attending Hawaii longline vessels, and a shift in the relative use of seabird bycatch mitigation methods. Notably, there was increased use of blue-dyed fish bait and decreased use of the more effective side setting. While the black-footed albatross population size has not changed significantly in the last decade, their distribution and attendance at longline vessels changed in response to inter-annual (El Niño – Southern Oscillation) and decadal (Pacific Decadal Oscillation) climate variability in the north Pacific Ocean.
Participants evaluated the relative promise of a comprehensive suite of alternative seabird bycatch mitigation methods for use in Hawaii’s longline fisheries. These included methods currently prescribed in the Hawaii longline seabird regulations, seabird measures adopted by Pacific tuna regional fisheries management organizations (Inter-American Tropical Tuna Commission, Western and Central Pacific Fisheries Commission) and methods identified as best practice by the Agreement for the Conservation of Albatrosses and Petrels. Participants reviewed 35 seabird bycatch mitigation measures and assessed them against criteria on efficacy, cross-taxa conflicts, practicality, economic viability, safety, durability and ability to facilitate compliance monitoring (Table 1). While seabird bycatch mitigation methods are presented individually in Table 1, participants recognized that combinations of methods are prescribed, in Hawaii and elsewhere, to obtain desired reductions in seabird bycatch rates.