Bluefin tuna farms fill demand as fishing ban restricts catches

At a bluefin tuna reserve in Aso Bay, it takes only about 50 seconds to remove a fish from the water and prepare it for shipment to market.

Hundreds of bluefins swim counterclockwise in a water-filled pen, 20 meters in diameter and 10 meters deep, in the bay located in Tsushima, Nagasaki Prefecture.

A 1-meter bluefin weighing 30-40 kilograms receives an electric shock and is hauled out of the water. In a series of swift moves, a fisherman shoves a spike into the fish's head and uses a plastic wire to severe its spinal cord.

The skilled hands of the fisherman then produce a knife and slice open the bluefin's silvery belly and remove its entrails before tossing it into an container of ice water, destined to become tomorrow's sashimi.

And it all takes less than a minute.

Fish farming is the key industry on Tsushima Island. About 200 fish preserves line Aso Bay.

Local fisheries farm various kinds of fish, from yellowtail to red sea bream.

Nowadays, the biggie is bluefin tuna.

A bluefin tuna can fetch more than 100,000 yen ($1,116) when sold to department stores and retail stores in the Kanto area.

The tuna farmers here breed young fish they catch offshore in fish reserves for three years.

They raise the young fish on sand lance, switching to sardines and mackerel as they mature.

They also feed the mature fish bonito at the final stage to restore the redness of their meat, which can fade as they grow older because of fat deposits.

It's an efficient assembly line-like system in which fishers don't have to worry about finding tuna in prime condition in the vast waters of the Pacific.

“With farming, you don’t have to worry about it," says Fumitoshi Nishiyama, president of fish farm Nishiyama Suisan. "We can provide marbled tuna in line with consumers’ taste."

Takaki Kusakabe, 49, fishes north of Tsushima in the sea near the border of Japan’s exclusive economic zone for juvenile tuna that can be raised on farms.

"Catching young tuna is a breeze," Kusakabe says.

His boat left the island at 2:30 a.m., heading north. Three hours later, it was in the sea near the border of Japan’s exclusive economic zone.

Dropping his line, Kusakabe says, “To catch (tuna) juveniles is the gravy train.”

The radar on his boat showed dozens of green dots. They were Japanese and South Korean fishing boats, most of them targeting juvenile tuna, he says.

Working until the afternoon, Kusakabe caught 25 bluefins.

With a young fish being sold for about 4,500 yen, the catch of the day was worth more than 110,000 yen.

Once traded at almost giveaway prices, bluefin tuna are now the driving economic force of the southern island.

Sixty percent of the 40,000 tons of bluefin tuna marketed in Japan during 2011 were from fish farms.

The man behind the fish-farming craze is Hideo Hirahara, who came up with the idea in the mid-1990s.

“Everyone said it would not be successful,” says the 78-year-old resident of Funabashi, Chiba Prefecture.

Hirahara had spent years in charge of tuna at a major consignment company at Tokyo's famed Tsukiji fish market.

After he retired from the firm in 1995, he moved to Spain.

There, Hirahara was soon pulling huge 200-kilogram bluefins out of the Mediterranean Sea by seine-haul fishing, a type of fishing that uses a net held down by weights and often used from a boat.

But the only time he was able to catch the tuna in large numbers was during their spawning period, when the young fish were so small and thin that they could only be used for canned tuna.

One day, Hirahara decided to save his large catch of young tuna and raise them for several months before shipping them to Japan.

His method involved nurturing the tuna carefully, as tuna that are moved violently often do not grow bigger or die.

The method enabled him to successfully raise "toro," or marbled tuna, and it attracted the attention of many Japanese and local business operators to try tuna farming.

With a spread of large-scale fishing, involving searching for schools of fish by plane, tuna exports to Japan quadrupled in eight years from 1998.

“Planned and massive exports enabled Japanese people to eat more tuna,” Hirahara says. “Otherwise, tuna can be extremely pricy.”

Hirahara's innovative method, however, has not come cheap.

The International Commission for the Conservation of Atlantic Tunas decided to restrict fishing quotas for tuna in the Mediterranean from 2007. And in 2010, at the meeting of signatories of the Washington Convention, also known as the Convention on International Trade in Endangered Species of Wild Fauna and Flora, a ban on international trade in Atlantic bluefin tuna was discussed.

The ICCAT decision on bluefin fishing in the Mediterranean Sea contributed to an explosion of tuna farming in Japan.

According to the Fisheries Agency, there are 137 bluefin tuna preserves in 14 prefectures, which produce 9,000 tons a year.

Most of them were captured young wild tuna raised in fish preserves, the agency said.

Building tuna farms requires approval from prefectural governors every five years.

In 2008, many trading companies and major fisheries companies were licensed or granted expansion.

On Dec. 29, 2012, Daisuke Takeuchi’s fishing boat arrived at a port in Oma, Aomori Prefecture, with a huge bluefin tuna weighing 218 kilograms.

To see a fish weighing more than 200 kilograms occurs once a day at Oma port, if that.

“It's a good size. It could fetch a lot of money,” says Yukihiro Ito, a sales official at the Oma fishermen’s cooperative.

Takeuchi's big bluefin was auctioned off for a record $1.76 million at the Tsukiji fish market on Jan. 5, to Kiyoshi Kimura, president of a nationwide sushi chain.

But tuna populations are continuing to drop.

The fish catch at the Oma fishermen's cooperative this season has been less than half that of five years ago.

Fish that are able to sell for huge amounts of money are becoming harder to find. And with the spread of tuna farming, tuna prices are getting lower.

Many fishermen and those in the fishing industry blame the overfishing of juvenile tuna for farming.

The Fisheries Agency plans to instruct prefectures, which license fish farming, not to permit any further expansion this year.

At Kimura's sushi restaurants, otoro, the best slices of bluefin from the New Year auction was served for the usual price--398 yen, with chutoro, the next best slices, for 298 yen each.

"You feel happy if you can serve sushi at a reasonable price," Kimura says. “In the past, we rarely had tuna. Even at a festive occasion, we could have no more than a few slices.

“(Our service) is a realization of everyone’s dream. Bananas used to be very expensive, you know? It is the same for bluefin.”