A RECORD-BREAKING tuna first tagged in the Great Australian Bight in 1994 has been recaptured off the NSW South Coast.
The southern bluefin tuna (SBT) originally tagged by Wade Whitelaw – using a conventional “spaghetti” tag fishing aboard the vessel FINA K in the Great Australian Bight – measured 97 centimetres and was estimated to be three years of age. The tagging was part of a large-scale CSIRO tagging program where information was registered in a CSIRO database, now holding records of more than 160,000 individual SBT.
Jason Garling recaptured the tagged SBT – measuring 185 centimetres and weighing 148 kilograms – on 29 June while fishing off the NSW South Coast aboard Charter Fish Narooma, skippered by Benn Boulton. The trophy-size SBT was captured on 24 kilogram conventional gamefishing tackle and took four hours to land.
The recapture sets two CSIRO records for the oldest SBT ever recaptured after tagging – 29.39 years – and longest “days at liberty” for a tagged fish, 9639 days.
CSIRO says, it’s not possible to tell how far this mature aged tuna has travelled or how long it spent on the East Coast. But scientists are confident this fish has made the journey between the spawning grounds in the north-east Indian Ocean and the Tasman Sea many times before.
Returned conventional tags, like the one found in this fish, complement recent advances in technology like electronic and genetic tagging. These technologies combined enable a more holistic picture of the movement, migration and behaviour of southern bluefin tuna.