Bluefin tuna–they’re so delicious, they’re on the brink of extinction. The human appetite for this majestic fish has spurred overfishing that has endangered the wild population, so researchers and aquaculture companies are trying to breed the fish in captivity. But so far bluefin tuna have proved very difficult to farm, since it’s impossible to replicate their natural reproductive cycle–researchers think the fish travel hundreds of miles to their traditional spawning grounds. The best results so far have come from an Australian company that is using hormone injections to get the big fish to breed.

Now researchers associated with a European project called Selfdott (an odd acronym for “self-sustained aquaculture and domestication of thunnus thynnus”) say they can successfully raise fish in captivity without using hormones. The New York Times reports that the first batch of fish, raised in floating cages, died after a matter of weeks or months, but researchers still think that with better food and parents more adjusted to captivity, the next group of fish will survive.

“If the results of this research can ultimately be commercialized, it can improve food supplies and contribute to economic growth and employment while also helping to ensure a sustainable management of bluefin tuna,” Máire Geoghegan-Quinn, the European Union’s commissioner for research, said this week. [New York Times]

(more…)

The media-savvy eco-pirates of the Sea Shepherd Conservation Society have a new target in their sights: commercial fishing boats that illegally scoop endangered bluefin tuna out of the sea.

The Sea Shepherd activists have become famous for harassing Japanese whaling ships; a reality TV show about their exploits documented the many tricks the activists used to slow down the whalers, including shooting stink bombs onto their ships and attempting to disable their propellers. With their new project, dubbed Operation Blue Rage, the activists hope to bring the same level of attention to the fight to save endangered tuna.

Stocks of bluefin tuna have fallen by roughly 85% since the industrial fishing era began…. Yet despite quotas that are arguably too high to begin with, quotas are still being ignored in many places [Ecopolitology].

(more…)

On Monday, we reported that the United States and the European Union were spearheading an effort to ban the international trade of bluefin tuna at the Convention on International Trade in Endangered Species (CITES). Now that the week is ending, so are the hopes for the proposal that could have protected the vanishing fish. It failed by a wide margin, thanks largely to the diplomatic efforts of Japan.

Japan consumes around three-quarters of the globe’s bluefin tuna catch, with almost all of it served raw as sushi and sashimi, of which it is the most sought-after variety [Christian Science Monitor]. It can be an expensive delicacy there. In addition, the transformation of sushi from a luxury dish to a cheap food available at the corner store seems to be one of the factors that has led to quickly diminishing tuna stocks. The Japanese government, while acknowledging that the species is in danger, pledged to defeat the proposal or else opt out of complying with it.

(more…)

Sushi chefs in Japan are keeping a close eye on Doha, Qatar this week as delegates at the Convention on International Trade in Endangered Species (CITES) debate the future of their beloved bluefin tuna. The fish, a delicacy in Japan that can sell for more than $100,000 apiece, is being overfished, and convention delegates aim to prevent the tuna from becoming extinct altogether. The proposal on the table: A complete ban on international trade of the fish to allow stocks to regenerate.

The bluefin tuna ban was proposed by Monaco, and the vote will probably come up next week. Japan has already dispatched a delegation to Doha with the message that Japan won’t comply with a total ban, and would instead prefer a fishing quota. But quotas have failed to help the depleted bluefin tuna stocks thus far. Japan last year pledged to help meet an accord to slash the total catch in the eastern Atlantic and Mediterranean by 40 percent, although environmental groups charge that such quotas are routinely exceeded [AFP].

(more…)

Sushi lovers, we’ve got some bad news. For a study that came out in PLoS One, researchers ordered sushi at restaurants across New York City and Denver, Colorado, and found that an alarming percentage wasn’t made from the fish it was advertised to be. More than half of the eateries weren’t completely clear and honest about the fish they offered, the study says. Some even mistakenly served up escolar, which can give people diarrhea and stomach problems.

Although their results were shocking, exposing sloppy sushi joints wasn’t their main goal. The scientists were trying to improve on a new species-identification technique, called DNA barcoding…. Their goal is to build a catalog of every fish species on earth so that anyone with a handheld DNA reader could definitively identify fish within minutes [Wired.com].

One reason researchers investigated sushi is that so much of it has been made from endangered species like the bluefin tuna. In the restaurants that lead scientist George Amato checked out, the device showed 25 percent of what was labeled as tuna on sushi menus was bluefin, Amato said. The device also has been used to identify the presence of endangered whales in Asian markets and fraud in the labeling of caviar and red snapper [UPI].

This study comes in the wake of an international ruling that reduces the quota for bluefin catch from 22,000 metric tons annually to 13,500 for 2010. But that isn’t enough for many environmentalists, nor for The New York Times editorial board, which this weekend called for the United States to list bluefin under the Convention on International Trade in Endangered Species. The law effectively bars commercial trade in any listed species, and has been helpful in protecting other animals like elephants and whales [The New York Times].

Related Content:
80beats: Scientists Say Ban Atlantic Bluefin Tuna Trade—And Sushi Chefs Shudder
80beats: Documentary on Endangered Bluefin Tuna Reels in Sushi Joints & Celebrities
80beats: Toothy Sea Monsters Need Sanctuary, Too

Image: flickr / avixyz

Atlantic bluefin tuna populations have declined so drastically that trade in the fish should be completely outlawed, says a new report. The population of the Atlantic tuna, a sushi staple, is now about 15 percent of the original stock size, says International Commission for the Conservation of Atlantic Tunas’ (ICCAT). The report has delighted conservation groups, who have criticized ICCAT’s regulation policies. The report was triggered by Monaco’s recent proposal to ban international trade in the Atlantic bluefin under the Convention on International Trade in Endangered Species (CITES) – a proposal that has gathered support from several other European countries [BBC News].

ICCAT has a history of setting quotas higher for the fish than scientists say is safe, while CITES seems to take a more proactive approach.Atlantic bluefin tuna are mainly caught from countries around the Mediterranean Sea, but most of the meat is consumed in Asia, particularly Japan. Japan has previously argued that commercial fish species should be controlled by bodies like ICCAT rather than CITES [BBC News]. In Japan, the fish are so highly prized that a single giant tuna can sell for more than $100,000 at the wholesale fish market. ICCAT will meet in 10 days to discuss the report.

Related Content:
80beats: Human Appetite for Sharks Pushes Many Toward Extinction
80beats: Are Fish Farms the Answer to World Hunger or a Blight on the Oceans?
80beats: Documentary on Endangered Bluefin Tuna Reels in Sushi Joints & Celebrities

Image: Wikimedia Commons

From pandas to polar bears, animals have served as icons for wildlife conservation. Now a new documentary called The End of the Line has helped the bluefin tuna, an endangered species, swim into the limelight by highlighting the overfishing common in fisheries today. Based on a book by journalist Charles Clover, the film has spurred some retailers to remove bluefin from their menus and stores and even moved some celebrities to pose naked with the fish to advocate conserving them.

A growing demand for bluefin tuna, commonly found in sushi and now as endangered as the giant panda, has not only decreased the fish‘s population, but also increased the number of undersized fish that are harvested, preventing the fish from reaching maturity. “Bluefin tuna has become the poster boy for the overfishing campaign. It’s on the buffers – it’s really on the slide down now,” Clover says.  “There are no large tuna anymore. There were bluefins of 250lb in Japanese fish markets when I went there four years ago – there are none now. A third of the catch is undersize” [BBC News].

The solution, experts say, doesn’t necessarily have to entail eschewing tuna altogether. Instead, consumers should stick to skipjack tuna, a more common variety, that has been caught using a method called pole-and-line, which avoids accidentally netting bluefish tuna and other sea life. Most commercial fishing operations that target skipjack use nets, Clover says, but “the skipjack run with all these other tuna species, like bigeye and bluefin. The skipjack are close to the surface and the bluefins swim further down, so there is often bluefin bycatch” [BBC News].

(more…)