ESTIMATION OF ALBACORE TUNA POTENTIAL FISHING GROUNDS IN THE SOUTHEASTERN INDIAN OCEAN

To maintain sustainable fisheries, albacore tuna is one of the commercial fish species whose management is regulated globally by the Regional Fisheries Management Organizations. Generally, sea surface temperature (SST) and chlorophyll-a (SSC) are used to determine fish suitability based on the catch data. In this research, we attempt to identify optimal habitats for albacore tuna in the southeastern Indian Ocean by analyzing in situ data based on onboard observers on tuna long line vessels from 2006-2019 and optimum interpolation sea surface temperature from NOAA-Advanced Very High-Resolution Radiometer and sea surface chlorophyll-a from Aqua MODIS satellites. The albacore tuna's habitat suitability index was examined using the Generalized Additive Model. The results suggested that albacore tuna inhabited waters with an SST range of 15-26 °C and SSC concentration of 0.075-0.125 mg/m 3 . In the Indian Ocean, most albacore tunas were captured at higher latitudes of 20°-30° S.