Sea Surface Temperature and Tuna Catch in the Eastern Pacific Ocean under Climate Change

Abstract

The increase in sea surface temperature (SST), a consequence of climate change, may lead to large-scale redistributions of global fish catch, including tuna in the Eastern Pacific Ocean (EPO). This paper applies the production function approach for modeling catch and SST using high-resolution gridded data for yellowfin and skipjack tuna catch in the EPO. We find a positive but nonlinear (i.e., logarithmic and quadratic) relationship between SST and the carrying capacity of tuna fisheries. The marginal product varies across species, distance from the equator, and the fishing method. For yellowfin tuna, the largest increase in catch occurs for unassociated and dolphin sets in the Northern EPO, while for skipjack tuna the largest increases in catch occur for unassociated and floating object sets in the Southern EPO. These thermal responses to ocean warming may lead to more segregated distribution and increased specialization in effort across the Eastern Pacific.