A massive fleet of commercial southern bluefin tuna boats has migrated to the south-east coastline of South Australia as the industry battles the worst fishing season weather conditions in 10 years.

Key points:

  • Thousands of live tuna will be towed to Port Lincoln for key export markets
  • Cooler weather conditions caused by La Niña are hampering tuna fishing efforts
  • Dozens of tuna fishing-related vessels and six spotter planes are operating off the state’s south-east coastline

More than 40 vessels and six spotter planes are involved in the search for large schools of bluefin tuna off the picturesque tourist town of Robe.

About 10,000 fish at a time will be captured and towed in cages to farms at Port Lincoln — the home of the state’s tuna industry — to be grown out for key markets in Japan and China.

Australian Southern Bluefin Tuna Industry Association chief executive Brian Jeffriess said the La Niña weather event was causing problems for the sector.

He said the cooler weather conditions were fuelling “unpredictable” fishing trends and lower catch rates.

He said it was important the industry was successful in 2021 catching given it underpinned the Port Lincoln economy and was a global leader in tuna farming.

Tuna not coming to the ‘surface’

Mr Jeffriess said fishing efforts were proving difficult as tuna were not coming to the surface due to the cooler conditions.

“We have no idea where the fish are, in reality,” he said.

Spotter planes have been flying off the coastline trying to pinpoint schools of tuna and the size of the fish.

The industry’s performance on farming the tuna leads the world, but it still relies on catching the right fish at the right time.

Fishers are searching for tuna sized about 15 kilograms, which will then double their weight in a farm setting.

“We’re doing reasonably well but, at the moment, you can only fish one day in every five because of the weather and the waters are too cold,” Mr Jeffriess said.

“It’s really hit or miss business.”

Pandemic drives market uncertainty

The industry is also facing turbulent market conditions fuelled by the pandemic and other global trends.

“These fish will be harvested in June, July and August,” Mr Jeffriess said.

“Between now and then, with COVID-19 and a whole range of world events, that is again a risk.”

Tuna fishing vessels moored off the Robe coastline after migrating from Port Lincoln.(Supplied: Gretel Sneath)

He said prices had already slumped across world markets.

“You do not know what the price may be in six months’ time, you do not know what the currency value or the value of the Australian dollar against the Japanese Yen or China Yuan may be at that stage,” Mr Jeffriess said.

Mr Jeffriess expressed hopes the La Niña event would end later this month.

“That’s the nature of fishing,” he said.

“Around 1,000 families in Port Lincoln are directly dependent on tuna fishing and [it] hits you every day when you wake up in the morning.”