Natal origin of Pacific bluefin tuna Thunnus orientalis inferred from otolith oxygen isotope composition.

The article discusses a study which investigated the natal origin of Pacific bluefin tuna Thunnus orientalis inferred from otolith oxygen isotope composition. The study demonstrated that otolith oxygen isotope values varied from -2.5 to -2.2% between the otolith core for age-0 tuna caught in the Japan Sea, while those caught in the Pacific Ocean varied between -2.8 and-2.2%. It was also observed that the temporal difference in experienced water temperatures produces an earlier increase of otolith oxygen isotope values for tuna caught in the Japan Sea than in the Pacific Ocean.