Total Allowable Catch of Indonesian Southern Bluefin Tuna Thunnus maccoyii and Its Potential Resources in The Indian Ocean

Abstract

Southern Bluefin Tuna (SBT) is a high value species fished by many countries including Indonesia, and its fishing activities has been regulated by CCSBT. This study aimed to determine the potential resource of Indonesian SBT, utilization, and review of the Total Allowable Catch (TAC) of Indonesian SBT. This research was conducted from January 2017 to April 2018. The primary data used in this study were the otolith samples and the enumeration data of SBT landed in Benoa port from 2012-2017. Virtual Population Analysis (VPA) used in this research was based on a direct aging method using otolith. This research showed that the catch at age structure was distributed from 5-22 years with mean and mode of age were 9.63 and 9 years. The average of the exploitation rate measured was 0.191 per year meaning that the level of exploitation was categorized as underfished. The optimal assumption of the exploitation rate estimated in the range of 1,577 to 2,630 tons per year which is higher than the TAC provided by CCSBT. It was concluded that from 2015 onwards, the catch efforts were more effective and efficient with the increasing level of the exploitation and the decreasing number of efforts.