In hot water: How marine heatwaves are transforming the recreational albacore fishery in the eastern North Pacific

Abstract

Albacore tuna (Thunnus alalunga: Scombridae) are a socioeconomically important species globally. A portion of albacore in the North Pacific stock recruit to the California Current Large Marine Ecosystem as juveniles, where they undertake seasonal inshore-offshore migrations. A series of marine heatwaves starting in 2014–2016 produced unprecedented oceanographic conditions in the northern California Current Large Marine Ecosystem, during which time recreational albacore landings in Washington State increased by 950.2 %. Fishing effort in this fishery increased by 1109.7 % during the same time period. We used Generalized Additive Mixed Models to show that a thermal habitat compression index was strongly associated with this increase in landings. During marine heatwaves albacore thermal habitat likely became more available closer to shore, and recreational fishers appeared to opportunistically increase fishing intensity to target them. In contrast, the catch per unit of effort (fish per trip) in this fishery was hyperstable, and less responsive to environmental drivers. While our results show that landings rose sharply during a recent period of ocean warming, effort from smaller private fishing vessels has been increasing since 2012, suggesting that social drivers of effort and participation are also important in this fishery. Given the complex behaviours of both albacore and fishing fleets, their response to future climate change will be more complicated than a simple function of sea surface temperature. However, this emergent fishery may represent an increasingly important source of supplemental revenue in coastal communities where other historically important fisheries are declining.