"The stock is down over 97 percent from pre-fishing levels, so there is no doubt the species needs to have some protections put in place," Duke University research scientist Andre Boustany tells The Salt via email.
One of the problems with current fishing patterns, says Catherine Kilduff, a staff attorney with the Center for Biological Diversity, is that most – possibly more than 98 percent, she says – of the Pacific bluefin that are caught and processed are immature juveniles that have never reproduced.
"So the baby fish never grow up to be moms and dads, and the adult fish eventually die," Kilduff says. "We feel this is a recipe for extinction."
The international fishery essentially manages itself, setting its own quotas each year, and critics say too many tuna are taken. Boustany, for one, says the fishery managers' population recovery goals are much too modest: By 2024, he says, "the current management measures are only aiming to rebuild the stock to" around 6 percent of what it would be if the Pacific bluefin wasn't fished.
And "almost all of the conservation measures that have been put in place to meet this low target are voluntary," writes Boustany. "There is a reasonable probability that this target will not be met."
The process of considering the petition and eventually listing the Pacific bluefin could take about two years, says Kilduff.
She says an endangered status would make it illegal to catch and kill Pacific bluefin in American waters, which extend 200 nautical miles from shore. Kilduff says it would also forbid Americans from possessing the fish even when outside of the United States, and prohibit the sale or trade of Pacific bluefin within the United States. For instance, most of the Pacific bluefin captured by Mexico, and then fattened in open-ocean pens before being slaughtered, is sent to Tokyo via United States ports, according to Boustany. An endangered listing would ban this activity.
Bluefin tuna travel great distances across the ocean, through waters governed by many different nations – including Japan, where the bluefin's fatty pink flesh is highly prized as sashimi. The migratory nature of the bluefin has made sustainable fishery management a challenge, since it requires the close cooperation of numerous national governments.
It's also part of the reason why protection under the Endangered Species Act would have limited effects on the fishery and the species' population. Of the 37 million pounds of Pacific bluefin caught by fishermen in 2014, American fishermen caught just 2 percent, according to data provided by Michael Milstein, a public affairs officer with NOAA Fisheries. (Japan took about half and Mexico almost 30 percent.)
Likewise, a relatively small amount of Pacific bluefin is consumed in the United States. According to federal catch data, the United States imported only about 3 percent of 2014's landings of Pacific bluefin tuna.
The United States' small role in the bluefin industry is why some conservationists feel listing the Pacific bluefin as endangered would be largely symbolic.
"It would affect fishing for Pacific bluefin in U.S. waters and would also stop imports of Pacific bluefin into the States, and that would send a major signal to the global market" that current fishing trends are not sustainable, says restaurateur and seafood sustainability consultant Casson Trenor, whose San Francisco sushi restaurant group Tataki has vowed never to serve bluefin tuna.
While Pacific bluefin stock assessments show a slight population jump – from 2 percent to 2.6 percent of its unfished size – from 2012 to 2014, Boustany is skeptical that the rough modeling system used to make these estimates is actually capable of detecting such subtle changes. He tells The Salt he believes that, since the species has been in almost nonstop decline for decades, the Pacific bluefin's numbers are possibly still dropping.
The Western and Central Pacific Fisheries Commission and the Inter-American Tropical Tuna Commission are the two organizations that manage the bulk of the Pacific bluefin catch.
The IATTC, which is convening in southern California this week to consider the next year's fishing regulations, said no one was available to comment for this story. The WCPFC, based in Micronesia, did not reply to multiple emails.
Buzz Brizendine, captain of the San Diego-based recreational fishing boat The Prowler, says he thinks listing Pacific bluefin, and thereby banning fishing for the species, would be unfair and relatively ineffective.
"Recreational fishermen have already had their daily bag limit on Pacific bluefin reduced from 10 to 2 fish," says Brizendine, who takes customers fishing for bluefin in the summer months. "We've already made a significant contribution to reducing the catch."
Brizendine sits on the Pacific Fishery Management Council, the advisory panel that makes recommendations to the U.S. government on how to manage many species. He says efforts to reduce mortality of Pacific bluefin must be focused on the western Pacific – the waters near Asia – where more than three-fourths of the catch is taken.
Some depleted but commercially valued fishes, like several strains of Chinook salmon and a handful of rockfish species, have been afforded strict protections by the federal government. Kilduff notes that her organization petitioned the U.S. fisheries service in 2014 to add the Pacific bluefin to its list of species that can't be fished under regulations.
"They denied that petition [two weeks ago]," she says. "So, we've tried to get them to take action before, and they haven't."
That, says tuna researcher and author Carl Safina, is simply because Pacific bluefin are so valuable. He signed the petition but thinks the odds of getting the Pacific bluefin listed are slim.