Conservation advocates are challenging a new fisheries rule that increases the take of rare Atlantic bluefin tuna, a species already under pressure from overfishing and illegal commerce driven in part by Japan’s nearly insatiable demand for sushi-grade tuna.

Atlantic bluefin are listed as a species of concern under the Endangered Species Act. The species is also listed as endangered on the IUCN Red List. Most other species of tuna are also identified by the IUCN as being in trouble.

The Center for Biological Diversity last week filed a lawsuit against the National Marine Fisheries Service challenging seeking to halt the dramatic expansion of commercial fishing from Massachusetts to Florida in an effort to prevent bluefin from being fished to extinction.

“Bluefin tuna were once the giants of the sea, but overfishing has depleted the ocean of this remarkable fish. It’s completely backwards to ramp up fishing of bluefin tuna at a time when they’re increasingly rare, said Catherine Kilduff, a staff attorney at the Center.

The fisheries service says the rule will convert potential dead discards to live landings and expand fishing commercial and recreational fishing opportunities.

But western Atlantic bluefin have declined by more than 80 percent since 1970 due to overfishing. The Fisheries Service’s latest rule nearly doubles the number of bluefin tuna that can be caught each day, as well as lengthened the fishing season. Because of the longer fishing season, bluefin tuna catches will shift from northeastern waters to include the mid- and south Atlantic states of North Carolina, South Carolina, Georgia and Florida.

“This rule enables fishermen to chase the remaining bluefin tuna down the Atlantic Coast on their way to reproduce in the Gulf of Mexico. At some point, the last bluefin tuna will be caught, and there’ll be no fishery left at all, said Kilduff.

Atlantic bluefin, listed as a species of concern under the Endangered Species Act in June, grow to be as large as 1,500 pounds and can live for more than 30 years. Crossing the Atlantic Ocean in a matter of weeks, bluefin tuna from the Mediterranean Sea visit U.S. waters to feed before returning to the Mediterranean to reproduce. A separate and much smaller population of bluefin tuna spawn only in the Gulf of Mexico.

An international treaty sets the U.S. quota for bluefin tuna, but the treaty has failed to rebuild the imperiled bluefin tuna population. Bluefin tuna are so sought after for sushi that a single fish sold for almost $400,000 in Japan, although more typical prices are $10,000 to $20,000 per fish. The high demand has spurred illegal and unreported fishing, which has prevented the recovery of bluefin tuna populations.

In response to the decline of the bluefin, the Center last year launched a nationwide boycott of bluefin tuna. Visit for more information. More than 35,000 people have joined the Center’s campaign and pledged not to eat at restaurants serving bluefin tuna; dozens of chefs and owners of seafood and sushi restaurants have pledged not to sell bluefin.