Hideki Nakano and Hiromu Fukuda

Session 5, Talk 3, 19/1/16 @ 0900 hrs

The Pacific bluefin tuna (PBF) has been exploited by several countries using many kinds of fishing gears which catch PBF of different ages since more than a century ago. The latest stock assessment of this species was carried out by the PBF Working Group of the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean (ISC PBFWG) in 2014 using data up to 2013. The input data for the stock assessment covers catch amount and size composition data of most of the major fisheries. It also includes representative indices of adult abundance and recruitment strength. Given those data rich situation especially recent 20 years, PBFWG conducted the assessment using an integrated statistical length based age-structured model (Stock synthesis 3). Although there are still uncertainties in the model associated with the data and assumptions, the model results generally suggested that spawning stock biomass (SSB) largely fluctuated throughout the assessment period (1952-2012), and the SSB has been declining for more than a decade. The current (2012) SSB level is near historic low levels and the current F (2009-2011 average) is above all target and limit biological reference points commonly used for management. The stricter management for this stock has started in 2015 through the catch and effort control, and the stock projections in 2014 assessments suggested that those measures would contribute to the stock recovery. The next stock assessment, which will accompany the improved data and assumptions with less uncertainty, is scheduled in March 2016.

Contact:  H. Nakano,National Research Institute of Far Seas Fisheries, Fisheries Research Agency, Japan, This email address is being protected from spambots. You need JavaScript enabled to view it.