Length-Weight Relationship and Catch Size of Bigeye Tuna (Thunnus obesus) Landed in Benoa, Bali, Indonesia

The research was conducted at the Tuna Fisheries Research Station, Denpasar, Bali, in July 2018 (3 weeks duration). There were several types of high-value fish incorporated into this research: tuna, skipjack, shrimp, cob, mackerel, snapper, squid, reef fish (grouper, baronang, lobster / barong shrimp) and ornamental fish. Seaweed processing was also assessed. Benoa Fishing Port is one of the tuna landing base bases in Indonesia. It is the main port in Bali Province and ranks beside Muara Baru (Jakarta), Pelabuhan Ratu (West Java) and Cilacap (Central Java). This research aim to identified length-weight relationship, and proportion of proper catch size of bigeye tuna. Herein, bigeye tuna (Thunnus obesus) was identified visually and then assessed. The first identifier is the large size of the eye. The growth pattern of big eye tuna (Thunnus obesus) landed in Benoa Fishing Portis is isometric, where the length increase is equal to weight gain (isometric positive). The length distribution of big eye tuna was in range of 81-170 cm FL (334 fishes are obtained), and the distribution of weights varied in size from 11-95 kg, with the most common catch size being in the range of 16-20 kg (95 fishes). Of note, 60% of the fish had not reached the proper catch size.