Tuna spawning to come forward

CLEAN Seas Tuna will aim to have its next batch of southern bluefin tuna fingerlings grown out to one kilogram before the winter comes to increase their chances of survival.

The company's chief executive officer Dr Craig Foster said the company's main vision for the future would be propagating southern bluefin tuna at Arno Bay, after it was announced earlier this year yellowtail kingfish operations would be moved to Port Augusta.

"Come spring, our efforts will be farming tuna," Dr Foster said.

Spawning of southern bluefin tuna has been bought forward to late September to help the fish escape the cold winter temperature once the fish are transferred to sea.

"We have been bringing forward the spawning, they used to spawn in January," Dr Foster said.

"It is a risk every time we bring the spawning forward.

"We want them (the tuna) to be at least one kilogram; they are much more robust and capable of surviving winter."

In the past, the tuna were transferred to sea weighing between 250 grams to 400 grams, and Dr Foster said he was confident the larger weight would give the tuna a better chance at survival.

Meanwhile, the company is edging closer to finding a cure for the sick yellowtail kingfish, which has seen the mortality rate double this season due to gut enteritis.

Dr Foster said the company would host a workshop this week in Adelaide and has invited key fish pathologists from around the country to attend and help diagnose the problem.

Two fish veterinarians from Canada and Japan with experience in kingfish will also visit the company's kingfish for three days this week to try and find a solution to the disease.

At this stage the problem had not been officially diagnosed, but the company believes it may stem from the nutrition and food given to the fish.

"We are quite optimistic we will have the answer in the next couple of months," he said.

Dr Foster said although kingfish operations had been moved to Port Augusta so the company can focus on its southern bluefin tuna operation in Arno Bay, the company could move the kingfish back to Arno Bay in the next couple of years.