Fishermen near Melbourne assumed two giant fish they caught were local tuna, but DNA showed them to be Pacific bluefin tuna, which spawn near Japan

Two large tuna caught off Western Port Bay near Melbourne in July 2026—one weighing about 364 pounds and the other about 290—were initially taken by recreational anglers for southern bluefin tuna. DNA testing by CSIRO later confirmed they were Pacific bluefin tuna (Thunnus orientalis), making them Victoria’s first recreational Pacific bluefin catches confirmed genetically. CSIRO said the announcement came October 14. The fish were caught in water 50 to 60 meters deep, with anglers reporting features that didn’t match southern bluefin, including differences in fin lengths. CSIRO conducted a first ID screen and then forensic-grade sequencing.