Unsustainable sushi

There may be plenty of fish in the sea, but none are quite like the bluefin tuna—the perfect predator by some opinions. Though it lacks the illustrious dentition of many sharks, the bluefin, which lives around the globe, can grow to nearly a ton, accelerate faster than a race car and sustain speeds of more than 50 miles per hour. No smaller fish can escape a hungry adult bluefin, and virtually no larger fish can catch one.

Yet evolution never quite equipped this hunter to evade the pursuit of fishermen, and today the bluefin tuna is a favorite on sushi menus worldwide.

The bluefin’s bright-red muscle meat, cut from the flanks of the fish, is often served as maguro, but it’s the creamy, fat-laden belly that creates such a stir among sushi devotees and fleets of factory-sized vessels. This revered flesh is called toro, and at Ju Hachi on S Street, diners hand over $12.50 for just 2 ounces. At Mikuni on J Street, it’s $19.50. When such a morsel hits the tongue and melts like butter, it may be the climax of the bluefin saga and the most appreciated experience in seafood—but it’s a short-lived pleasure, and activists with Greenpeace, World Wildlife Fund, FishWise and other groups are asking whether it’s worth the price, and they’re not talking dollars and cents. They’re talking the species itself.

Commercial extinction is approaching fast for the Atlantic bluefin. The fish now resides at just 10 percent of its historical biomass, and experts give the industry approximately five years to live. Last fall, biologists warned fishery managers that the dwindling eastern Atlantic bluefin could not withstand catch quotas above 15,000 metric tons per year. The scientists even advised that 7,500 metric tons would be preferable—a catch rate that could actually allow the population to rebuild. The 46 nations that fish for Atlantic bluefin, all part of a group called the International Commission for the Conservation of Atlantic Tunas, considered this advice and convened in Morocco in November to discuss the matter. For several days they scratched their chins thoughtfully and deliberated wisely before deciding to self-impose a generous quota of 22,000 tons of bluefin tuna for 2009.

That, some environmentalists have said, could be lights out for the eastern Atlantic bluefin.

On the west side of the Atlantic, the fishery is managed separately, and the number of tuna also appears to be dwindling. The local quota was recently set at 1,675 metric tons. Shared largely between Canada and the United States, this figure represents approximately 15,000 to 20,000 fish. Thing is, the fleet has failed to catch its limit in years for lack of fish. In 2008, commercial landings equaled just 24 percent of the quota.

As the Atlantic bluefin fisheries fail, the eyes of the industry are turning toward the relatively abundant Pacific stocks. Mikuni serves Pacific bluefin, often caught near Australia. Ju Hachi’s bluefin is also from the Pacific, sourced from near Baja California. The fish are not immediately killed upon capture. Rather, entire schools are rounded up, then transferred to cages anchored near the coast. There, the fish are fattened on sardines. They gain weight, growing thick around the belly, and in several months they attain slaughter size—usually 30 to 60 pounds. This system of “ranching” is growing increasingly popular worldwide and is considered problematic both for its consumption of sardines—20 to 30 pounds for a single pound of toro—and its dependence on young tuna that will never get a chance to reproduce.

Some experts predict that the Pacific bluefin will go the same way as the Atlantic unless consumers quit eating it. Casson Trenor, author and sustainability expert with FishWise, a restaurant-consulting group, addresses the subject in his new book, Sustainable Sushi: A Guide to Saving the Oceans One Bite at a Time. The Zagat-sized guide, available at Borders, discusses each of several dozen marine species that appear under Japanese names on most sushi menus. The handbook advises against eating farmed salmon, hamachi, unagi and other sushi standards, but bluefin tops the list of no-nos.

Trenor says consumers must shift from eating apex predators like tuna to items lower on the food chain, where creatures like squid, anchovies and mackerel grow faster, swim in vaster quantities and usually contain less accumulated mercury.