Sushi cows of the sea

Sustainably farmed bluefin tuna? Come on -- what's the catch?

Published July 8, 2009 4:02PM (EDT)

Can we stop worrying about the fact that 90 percent of the world's big fish, including the prized-by-gourmet-sushi-lovers bluefin tuna, "have almost disappeared from the oceans since the advent of industrial fishing in the 1950s"? According to an extremely enthusiastic report from Bloomberg News' Stuart Biggs and Madeleine Pearson, "Breeding Breakthrough Helps Sushi Baron Create Sustainable Tuna," farmed bluefin is right around the corner!

Hagen Stehr was at home in Adelaide, Australia, on March 12 when his company's chief scientist called with news that their bet of about $48 million on the breeding of southern bluefin tuna in captivity -- a feat never accomplished before -- might finally pay off....

Stehr, chairman of Port Lincoln, Australia-based Clean Seas Tuna Ltd., rushed more than 500 kilometers (311 miles) to his company's fish hatchery outside Arno Bay in southern Australia. With tears in his eyes, he pushed his Toyota Land Cruiser to its top speed of 180 kilometers an hour as he raced to see the fertilized eggs for himself. As the owner of a fishing fleet during the past four decades, Stehr had helped empty the seas of the bluefin tuna used in sushi restaurants from New York to Tokyo. Now, at age 67, he believed he was on the verge of saving the tuna -- and the industry that made him rich -- from the threat of extinction.

What follows is a story of fish breeding perseverance and good old-fashioned human ingenuity. But at the end of the day, it's also a story of triumph and deliverance for those who can't bear the thought of giving up "the rich taste and creamy texture of" bluefin tuna.

To get the bluefin to breed, scientists at Clean Seas designed the tank to simulate conditions in the ocean. Using overhead lights to suggest the sun and moon, saltwater piped in from the ocean, artificial currents and temperature controls, the scientists have tried to re-create the experience of a spawning journey for the fish.

Awesome. Fish breeders rock.

Oh, and to get the reluctant female tuna to produce eggs, they were injected with hormones via spearguns.

There's also the problem of feeding the tuna, notorious predators near the top of the marine food chain. Because, you see, it's not just the bluefin that are disappearing from the oceans, but also the fish that bluefin eat, like mackerel and sardines.

But not to worry: "Clean Seas is developing wheat-based pellets to feed its tuna."

Hm. Call me crazy, but something tells me that the creamy flesh of tuna raised on a diet of wheat pellets from eggs produced by hormone-hopped-up mothers might not be quite as tasty as soon-to-be-extinct wild tuna. What do you think?

By Andrew Leonard

Andrew Leonard is a staff writer at Salon. On Twitter, @koxinga21.

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