Thousands of tuna, their silver bellies bloated with fat, swim frantically around in netted areas of a small bay, stuffing themselves until they grow twice as heavy as in the wild. Is this sushi’s future? Tuna raised like chickens or cows?
As the world’s love affair with raw fish depletes wild tuna populations, long-running efforts to breed the deep-sea fish from egg to adulthood may finally be bearing fruit. Though the challenges are daunting, the potential profits are huge.
By the end of this year, an Australian company says it will begin selling small amounts of southern bluefin tuna hatched in its fishery. A Japanese firm breeding the more prized Pacific bluefin tuna hopes to start sales in 2013 and ship 10,000 fish by 2015.
Whether tuna farming will become viable on a large scale remains an unanswered question. Tuna are much harder to rear than the widely farmed salmon and shrimp. They are large and need room to swim. They only spawn under certain circumstances. In some experiments, fewer than 1 percent of the babies survive. And those that do eat so much that they could wipe out other fish species.