Transport, distribution and growth of larval patches of Pacific bluefin tuna (Thunnus orientalis) in the northwestern Pacific Ocean

摘要

The objective of the present study is to provide a clearer understanding of the early life ecology of Pacific bluefin tuna (PBT), Thunnus orientalis, with respect to changes in the recruitment process in relation to environmental conditions for a basis for stock management in the northwestern Pacific Ocean. Seven high density larval populations (patches) of PBT were tracked with reference buoys, and repeated sampling was carried out at study sites in the northwestern Pacific Ocean for periods ranging from 28 to 171 hours between the months of May and June from 2004 to 2008. The feasibility of detecting and tracking larval patches as well as appropriate protocols for plankton net observation were determined, and larval transport and distribution were examined. Survival and growth were observed in order to develop a model for these characteristics in larval stage PBT. This document is brief summary of the previous studies.