The Spatial Analysis in Tuna Habitat Related to The Ocean Variability in The Indian Ocean

One of marine fisheries resources utilization problems is the difficulty of determining the exact fishing ground, including for big pelagic fish. The use of fishing ground map by local fisherman has not shown significant catches in fishing operation. The research aims were to inventory catch and fishing ground of tuna collected directly from Cilacap fisherman, to know the correlation between tuna catch composition and their fishing ground distribution, and to analyze the spatial correlation between fishing ground and oceanography variability in the Indian Ocean. The analysis applied to both tuna fish and baby tuna for the species of big eye tuna. The research applied spatial and temporal analysis of Aqua-MODIS images in the year of 2006 until 2015, and the analysis of big eye tuna catch effort for 2015. The research showed that based on fishing ground and catch, big eye tuna catch was 9.724 kg on August in the coordinate of 108.67 degrees E longitude and 09.50 degrees S latitude, big eye tuna (big and baby) was 17.092 kg on September in the coordinate of 108.83 E and 08.50 S, and big eye baby tuna was 7.896 kg on January in the coordinate of 107.00 degrees E and 08.00 degrees S. Bigeye tuna is more dominant caught than big eye baby tuna in Southern Java between 105.00 degrees to 110.00 degrees E longitude and 08.00 to 10.00 S latitude, and slightly in Southwestern of Java. Based on the distribution of big eye tuna fishing ground in the Indian Ocean described that big eye tuna were caught in the range of SST, chlorophyll -a, and SSHA of 25-30 degrees C, 0.10-0.71 mg/m3 and -0.14-0.16 m. The accuracy assessment of tuna fishing ground during 2015 by local fisherman associated with the prediction of potential fishing ground showed 78,82 % of accuracy.