Estimation of Yellowfinn Tuna (Thunnus albacares) Fishing Ground Based on Oceanographic Parameters in Fisheries Management Area 573, Indonesia

Yellowfin tuna (Thunnus albacares) is a group of large pelagic fish, one of whose habitat is in the Indonesia Fisheries Management Area (IFMA) 573. Estimation of Thunnus albacares can be done through Indonesian Weather Information for Shipping (Ina-WIS) which is a satellite image-based product from the Indonesian Agency for Meteorogical. Climatological, and Geophysics (IAMCG). The purpose of this study was to analyze the oceanographic distribution used for estimating Fishing Areas (FG) of Thunnus albacares. The research method is descriptive quantitative with oceanographic parameters used include Sea Surface Temperature (SST), chlorophyll-a concentration, and currents. Oceanographic parameter data used were taken from Ina-WIS and Aqua-MODIS data. Satellite observations were made at coordinates 110°-113° EL and 8°-9° SL as the dominant area of Thunnus albacares habitat in the eastern part of southern Java Island, one of which is Sendang Biru waters. The research obtained is based on the condition of oceanographic parameters in Sendang Biru waters can be used as FG of Thunnus albacares. Not all waters with good oceanographic parameters are followed by an increase in catches. Not all waters with good oceanographic parameters are followed by increased catches. There is a time lag for the target fish to gather in waters with good oceanographic parameters. SST conditions and chlorophyll-a concentrations in April ranged from 28.72 - 29.65 °C and 0.15 - 0.5 mg/m³ (high category). In that month, the catch of Thunnus albacares weighing >10 kg was 591 kg (<1 ton). Thus, it can be said that the occurrence of FG does not always coincide with the increasing condition of oceanographic parameters of a water body.