Potential Predictability of Skipjack Tuna (Katsuwonus pelamis) Catch in the Western Central Pacific

The Pacific Island countries have substantial socio-economic dependency on the fishery, and Skipjack tuna (Katsuwonus pelamis) is one of the most important species in the Western Central Pacific (WCP) in terms of its catch amount and associated international trade agreements on fishing right. It has been understood that catch amount of Skipjack tuna in the WCP exhibits spatial-temporal variability influenced by ocean-climate conditions, mainly by the El Niño-Southern Oscillation (ENSO). This study investigates statistical relationship between the catch amount and various ocean variables in the equatorial Pacific during 1990–2014, and evaluate potential predictability based on the relationship. Series of regressed spatial patterns of upper-ocean temperature, salinity, currents and precipitation represent ENSO-like variability, and their principal component time series are used to estimate the predictability of Skipjack tuna catch in the Federated States of Micronesia. It turns out 5 m salinity and 100 m temperature in the equatorial Pacific exhibit significant predictability of the catch amount on interannual time scales (up to about 3 years). This result can be applied to the other Pacific Island countries in the WCP and would have a broad impact on the fishery industry in the WCP and many other countries consuming the fish caught in the WCP.