Updated information on catch and effort of bigeye tuna (Thunnus obesus) from Indonesian tuna longline fishery

Bigeye tuna (Thunnus obesus) is one of the main targets for Indonesian tuna longline fishery in the Eastern Indian Ocean. The fishery has begun since early 1980’s, when deep longline introduced. There were two types of data used in this study; first was the skipper’s “logbook” data from the state-owned commercial tuna longline vessels based in Benoa Port (1978-1995), and the later was the scientific observer data conducted by Research Institute for Tuna Fisheries (RITF) from 2005 to 2017. Both datas then combined to produce nominal catch per unit of effort (CPUE) (no. fish/100 hooks). The result showed that the catch rates of bigeye tuna is declining over the years. The highest CPUE recorded was in 1992 (0.62), while the lowest was in 2016 (0.11). Efforts distributed mainly within 0-35 oS and 75 – 130 oE. While high CPUE areas mainly occurred between 5-20 oS and 30-35 oS. We are still in progress of completing the skipper’s “logbook” data entry in a hope of presenting the appropriate standardized CPUE in the future.