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Clearer Waters

It’s no secret that commercial fishing is responsible for much of the decimation of the ocean’s wildlife. Undesirable by-catch is pulled lifeless from nets and swept off the decks of ships, leaving only the most lucrative specimens.

This puts Australian Hagen Stehr in a league of his own.

Profiled by the Sydney Morning Herald, Stehr has operated his own tuna boats for more than 40 years, starting the Stehr Group in 1961 from a small savings; by the Eighties he controlled a fleet of 21 vessels.

By the early Nineties, though, he could see that the numbers of bluefin tuna, the foundation of his business, were dwindling. In an effort to protect his company he began raising captured tuna in ocean-based farms. This produced larger fish, but when other fishing operations began relying too heavily on a similar farming system, the bluefin population went into an even steeper nosedive.

Stehr, a veritable T. Boone Pickens of commercial fishing, started Clean Seas Tuna and has spent the last eight years and raised $58 million in capital to try and reverse the dramatic reduction in numbers among southern bluefin tuna by researching methods to better breed them in captivity.

It’s a formidable task. Bluefin tuna can swim 45,000 miles in 17 months to feed and spawn and die if unable to swim. In addition, bluefin are accustomed to eating their young.

To combat those natural instincts Clean Seas has designed a special tank to try and accommodate the tuna featuring overhead lights to simulate the sun and moon, a constant supply of natural saltwater from the ocean, and an artificial current to keep them moving.

Stehr’s research appears to be the solution to a long and complicated problem. Commercial tuna fishing was unregulated until the 1980s. As a result, rival companies struggled to kill the most fish in the least amount of time. Australia, New Zealand, and Japan tried to slow the damage by imposing strict weight quotas on fishermen. The resulting loss in income forced companies to catch more, smaller fish and raise them in farms to sizes previously unseen in the wild. Ultimately, this only ravaged the wild bluefin population even further and left tuna fishermen in even worse circumstances.

The eastern Atlantic bluefin, found in the Mediterranean Sea, appears to be in the greatest peril; a recent study from the National Institute of Aquatic Resources in Denmark predicted the species’ demise will occur sometime in the next ten years. The UN has tried, with limited success, to impose quotas and regulations on the region.

In Australia, Stehr’s work appears to be paying off. The females began laying eggs in March of this year and the mating continued for more than a month. Although there are still details to work out, Clean Seas intends to produce at least a quarter of a million fish by 2015, effectively replenishing the annual catch of Australian fishermen. According to Stanford marine science professor Barbara Block, “If Hagen Stehr can solve the issues surrounding breeding predacious fish, he’ll have a sustainable product that will last forever.”

You can watch the video about Jon’s visit to a tuna auction house in Tokyo here.

You can also check out ICCAT’s website to find out how this branch of the UN is trying to help. – ALEX NELSON