Australia’s fish whisperer dupes tuna into duplicating

March 7th, 2008 - 9:48 am ICT by admin  

By Sid Astbury
Sydney, March 7 (DPA) It’s been an experiment seven years in the making and has cost Hagen Stehr millions of dollars. But the German-born fisherman reckons that at the weekend all the effort and all the expense was worth it when he glimpsed the holy grail of Australian aquaculture. “It happened this Sunday,” the chairman of Port Lincoln’s Clean Seas Tuna said. “We had the male fish spermeating, the female released eggs and we have the tuna larvae hatching.”

Raising southern bluefin tuna in captivity rather than having to catch them on the high seas is a breakthrough that could effect a transformation in an industry that is worth 230 million Australian dollars ($215 million) a year.

The fish are an endangered species and since 1990 the annual quota has been set at 5,200 tonnes a year. Now, the fish are caught in the wild and then fattened in ocean feed lots before being frozen and shipped abroad.

Raising them in captivity means Stehr can circumvent the quota and sell as much as he can harvest to Japan, China, the US and Europe.

In Japan, which takes 80 percent of the catch and turns it into sashimi, individual fish can sell for as much as $1,000.

“We can potentially produce the fish year round,” he told DPA. “We’ve been trying to close the life cycle and we think we’ve almost done it.”

Sustainability beckons - and the possibility of dropping the quota to help depleted stocks in the Southern Ocean.

In the south-coast town of Port Lincoln, Australia’s tuna capital, Clean Seas has made fish breed by cheating them into thinking they are in the wild.

The listed company has monstrous tanks, each many times the size of an Olympic swimming pool, where the journey from deep-sea to breeding ground is simulated by adjusting sunlight, moonlight and even the water temperature.

“We get into their minds, we find the Y factor,” said Stehr, who arrived penniless in Port Lincoln in the early 1960s after jumping ship. Born in Salzgitter, he joined the merchant navy after a spell with the French Foreign Legion.

Stehr has no formal training, but has parlayed his success as a traditional fisherman into an alternative career as a fish breeder.

“Some fish are easier than others to breed,” he said. “The southern bluefin tuna is the holy grail, the cream of the cream, the ultimate.”

He puts his success down to perseverance.

“You have to be weak in the head, strong in the back and have deep pockets,” he said of his quest to replicate the successful captive breeding trials in Europe.

To the shopper, northern bluefin tuna are indistinguishable from southern bluefin tuna; only scientists can tell the difference.

The experiment will be complete when fingerlings produced by Clean Seas from its own brood stock are raised and shipped abroad.

Craig Bohm, campaign director with the Australian Marine and Conservation Society, has given a cautious welcome to the breakthrough.

He says it doesn’t necessarily mean the quota can be reduced, “but if it does lead to the industry relinquishing quota and allowing more of our threatened southern bluefin tuna to remain alive in the sea, that would be certainly most welcome by us”.

Stehr is also cautious, saying it will be some time before success can be termed complete. “It’s like a marathon,” he said. “It’s like we’ve entered the stadium. It’s like we can see the finish and there’s still 400 metres to go.”

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