Bigeye tuna catch limits lead to differential impacts for Hawai`i longliners

Ayers AL, Hospital J, Boggs C (2018) Bigeye tuna catch limits lead to differential impacts for Hawai`i longliners. Marine Policy 94:93–105. doi: 10.1016/j.marpol.2018.04.032

Bigeye tuna (Thunnus obesus, Scombridae) are a globally important commercial fish. About 60% of the world's bigeye is caught in the Pacific Ocean, where stocks have been subject to overfishing and longline fleets are governed by increased conservation measures. One conservation measure entails multilateral bigeye quota reductions. Since 2010, quota reductions have resulted in four extended closures for Hawai`i longliners. Previous research indicated that regulatory closures may result in differential socioeconomic impacts, but little is known about how four extended closures may affect fishers and fishing trips in a diverse longline fleet with 142 active vessels. The purpose of this research is to assess the trip-level impacts of closures on Hawai`i longliners and determine whether impacts could be lessened while sill meeting conservation measures. To do this, economic data and longline logbooks for Hawai`i longliners were analyzed from 2010 to 2015, and 28 longline fishers were interviewed in Fall 2015. Vessels allowed to fish during closures spent nearly two more days at sea not fishing compared to the same month in years without a closure, with no significant difference in trip length. Vessels with special permits are allowed to fish closer to port during closures, while the larger vessels (25% of the fleet) were restricted from retaining bigeye between 32 and 61 days a year, raising equity concerns across the fleet. Our findings also suggest that two levels of collective action may be needed to meet Pacific-wide economic and conservation goals for an economically and ecologically important pelagic common-pool marine resource.