GREEN
11/16/2008 05:12 am ET | Updated May 25, 2011

Endangered Species Sashimi: The Plight Of Bluefin Tuna

Bluefin tuna, one of the world's most highly prized marine species, have met their plight. These tuna, which the Monterey Bay Aquarium's reputed Seafood Watch list describes as "severely over-fished," are native to the Northern Atlantic and the Mediterranean, but are also commercially cultivated off the coast of Japan. Bluefin is particularly prized by sushi lovers, who covet its buttery toro (fatty belly meat). At Tokyo's Tsukiji fish market, a single fish can fetch upwards of $100,000.

Seafood Watch asserts that the species' Atlantic population has declined by nearly 90% since the 1970s, in part because the massive fish are slow to mature, and are often caught before they have had a chance to spawn. Although the EU regulators banned trawling for the fish last spring in the eastern Atlantic and Mediterranean, the stock has recently crept even closer to collapse.

Andrew C. Revkin over at Dot Earth writes that a new study, published by Science Magazine, highlights the ocean-crossing habits of two distinct populations of Atlantic bluefin tuna as a key contributing force to the devastation of the species:

Some fish that originate in the Mediterranean end up cruising the east coast of North America, inflating population estimates there. But commercial catches of large bluefin in those waters -- mostly bound for the sushi trade -- are still almost entirely tuna that originated in the Gulf, according to the study. Carl Safina, a marine biologist and ocean-conservation campaigner, said a strict moratorium on bluefin fishing in American waters was the only way to stave off destruction of the Gulf breeding population.

I asked fisheries officials at the National Oceanic and Atmospheric Administration about the study, and they replied that it provided more evidence of overfishing by Europe. The study, said Monica Allen, a spokeswoman for the fisheries office, "points out that the smaller western stock is 'disproportionately affected by higher fishing rates in the eastern management zone.' The U.S. has pushed for strong international action to stop overfishing of bluefin tuna by eastern harvesters in the Mediterranean and the eastern Atlantic Ocean."

Alarmingly, although the tuna are widely considered critically endangered, they continue to be pursued and consumed with great zeal. Last month, Treehugger's Matthew McDermott reported that undercover investigators have discovered three Nobu restaurants in London serving endangered Atlantic bluefin -- and passing it off as non-endangered tuna:

According to an article which ran in the Telegraph a little over a week ago, undercover investigators from Greenpeace asked the staff at three London branches of Nobu what type of tuna different menu items only described in Japanese came from. Though told that none of them was from Atlantic bluefin, when DNA testing was done on the samples two out of three times the fish was Atlantic bluefin, while the third test was inconclusive.

While it is not illegal to serve Atlantic bluefin, many chefs in London have stopped serving it owing to it being listed as critically endangered by sustainable seafood watch groups

Reuters reports that the Italian government has taken an equally cavalier stance on bluefin:

Italy overshot its quota of bluefin tuna last year by five times, showing that rules meant to save the giant fish from extinction were failing, the conservationist group WWF said on Tuesday in a report.

WWF said Italy was 700 tonnes over quota and has a fishing fleet capable of landing twice what it is legally allowed.

"Italy's illegal activity in the Mediterranean bluefin tuna fishery is not just a threat to this magnificent species, but also jeopardizes the future of those trying to fish this resource in a sustainable and legal way," said Michele Candotti of WWF, formerly the World Wildlife Fund.

WWF is calling for a moratorium on bluefin tuna hunting to allow stocks to recover from what it says are levels that endanger the species' survival.

The actor Ted Dansen, who serves on the board of Oceana, a foundation that researches and campaigns on marine issues, recently wrote an impassioned opinion article for BBC News on tuna. He too calls for an immediate stop to bluefin fishing:

Bluefin need a generational breather to prevent total collapse. In the meantime, the data gathered by researchers aboard Oceana's MarViva Med tells us that the quotas that are in place are not effectively enforced and are ignored by the tuna fleet.

Even as a lay person, not a scientist, it's abundantly clear to me that overfishing is pushing our oceans towards an irreversible collapse. Bluefin tuna is just one species that's already at the brink of extinction. We can bring the tuna back, but only if we act now.

Saving the mighty bluefin will require not just changes in government regulations but also changing people's minds. Only when individuals stop demanding or even accepting the fish on their dinner plates will demand diminish and fishermen take heed. As Fen Montaigne wrote in National Geographic last year,

The world must begin viewing the creatures that inhabit the sea much as it looks at wildlife on land. Only when fish are seen as wild things deserving of protection, only when the Mediterranean bluefin is thought to be as magnificent as the Alaska grizzly or the African leopard, will depletion of the world's oceans come to an end.