High quality tuna to catch

THE southern bluefin tuna fishing season has already begun but most catching boats will head out to sea this week with plenty of fish spotted in the aerial surveys.

Australian Southern Bluefin Tuna Industry Association chief executive officer Brian Jeffriess said most companies would kick off the fishing season now that there were large areas of fish throughout the areas west and east of Port Lincoln.

The recovery of southern bluefin tuna stock has seen fish spread further and in recent years more tuna have been caught in the east.

Mr Jeffriess said one company had already caught, towed and transferred tuna into the pontoons in the tuna farming zone.

He said part of the continued strong recovery of the tuna stock was that catching boats could target the highest quality fish.

“This year the quality is the best we have seen,” Mr Jeffriess said.

“The industry is also benefiting from the very high quality of sardines and mackerel in the Great Australian Bight in the last five years.”

Mr Jeffriess said one of the biggest positives about the high quality sardines and mackerel was that the tuna grew well in the fishing grounds before they were caught.

He said the second benefit was the sardines being used in the farms were also high quality.

This is the fifth successive year of above-average upwellings in the Great Australian Bight and the south east and Mr Jeffriess said it was still unclear why this was happening.

“There is a large amount of research by the South Australian Research and Development Institute (SARDI) and CSIRO on the whole ecosystem in the Bight and this will start to produce answers in the next two years.”

Mr Jeffriess said this year was also the first year of the CSIRO gene tagging of tuna in the Great Australian Bight, which a Port Lincoln company would be taking on next year.

He said the tagging saw individual DNA samples taken from up to 10,000 tuna on the fishing grounds.

“Those samples are then matched with a larger number of tuna from the farm harvest in 2018,” he said.

Mr Jeffriess said the tagging was cutting edge research that would result in a more accurate and cost-effective measure of the tuna stock than the current aerial survey approach.

“This is another example of Australia being a global leader in fisheries research,” Mr Jeffriess said.