Modeling the habitat suitability index of skipjack tuna (katsuwonus pelamis) in the western and central pacific ocean

Abstract

Skipjack tuna (Katsuwonus pelamis) is the major target species in Taiwan pelagic purse-seine in the western and central Pacific Ocean with approximate 90% of catch rate in all harvested species. This study attempts to identify the habitat suitability index (HSI) for skipjack tuna in the western and central Pacific Ocean. Fishery data was processed for comparing with satellite data included sea surface temperature (SST), chlorophyll-a concentration (Chl-a), sea surface height (SSH), and sea surface salinity (SSS). In addition, SST and Chl-a satellite images were applied to oceanic frontal band detection that front gradient magnitudes were used for the HSI estimation. Preliminary results in this study revealed that HSI of skipjack tuna greater than 0.6 was confirmed, where SST and Chl-a front gradient ranged between 0.065 to 0.216 (°C/10km) and 0.003 to 0.005 (ratio/10km), respectively and SSH changed from −0.107 to 0.016 (m), SSS changed from 34.5 to 35.19(psu).