size and fishing ground ofwahoo (acanthocybium solandri cuvier, 1832) from catch data of tuna longline operated in indian ocean

Wahoo (Acanthocybium solandri Cuvier, 1832) is a member of the Scombrid family, is a pelagic (open ocean) species found worldwide in tropical and warm-temperate seas. It is fished throughout its range by artisanal, recreational, and commercial. Wahoo is one of the by-product species of the tuna long line fleets operate in Indian Ocean. This paper describes status of wahoo resource caught by tuna long line in Indian Ocean based at Benoa-Bali. Data obtained from onboard observer program on the tuna long liner based at Benoa-Bali during 2005-2010. Total of 85 trips of onboard observation were carried out with the total long line sets (one set per day) were 2873 times. The data covered the horizontal and vertical position of tuna long line hooks caught the wahoo, hook rate and fish size distribution. Data of horizontal fishing positions (coordinates) gained from the global positioning system availabled in the tuna long liners. The depth of the long line gear in the waters and teperature of waters were measured by mini-loggers TDR type SP2T-1200, brand: NKE Micrel. Hook rate of wahoo is calculated using the Klawe (1986) method. Result of research showed that the wahoos caught by tuna long lines based at Benoa spread horizontally between 1o31’-33o 40’S and 77o18’-117o53’E and spread vertically between the depth of 75.2- 285.7 m. From 85 tuna long line fishing trips, only about 50% of 85 tuna long line fishing trips caught wahoo with hook rate ranged 0.947-1.399 per 1000 hooks/setting. Size distribution of wahoo ranged 70-180cm with modus ranged 101-110cm.