Application of Satellite Remote Sensing on the Tuna Fishery of Eastern Tropical Pacific

Abstract

Tuna fishery is a major fishery in Taiwan, as in many other countries. Most of the tuna studies were based on the fish catch data, and their main subjects are related to the maximum sustainable yield of tuna. Both in managing the tuna fishery by the authorities (to maintain the size of standing stock), and in maximizing the catch per unit effort (CPUE) by fishing boats, one must know what are preferred océanographic conditions to tuna. After analyzing tuna catch data from a few experimental fishing boats in the eastern tropical Pacific Ocean, we reached the following conclusion: (1) For predicting the fishing ground of tuna, using the mean distribution of sea surface temperature (SST) or ocean color is not better than making no-prediction, i.e. using the mean distribution of tuna catch. (2) CPUE of Big Eye tuna is higher in regions of SST in 26°C∼28°C, surface Chlorophyll a concentration around 0.2 mg/m³, surface current speed above 0.15 m/s, or higher sea surface height (SSH). Because all the marine environmental parameters may change quickly with time or in space, satellite remote sensing data can provide the near real time observation for timely predictions of tuna fishing ground in the vast ocean.