Frustrated by policies that increase overfishing, a San Francisco-based environmental group filed suit in federal court last week against the National Marine Fisheries Service, charging that its most recent rule changes are allowing additional harvesting of bluefin tuna by expanding the fishing season.

Bluefin tuna, a highly prized sport and commercial fish, travels the oceans of the world. One large fish can sell for tens of thousands of dollars in a Japanese fish market. It was once a familiar fish in these waters, harpooned by local fishermen south of the Vineyard. Their population here has dwindled and moved offshore.

On May 27, the National Oceanic and Atmospheric Administration (NOAA), which operates the fisheries service, turned down a petition--filed a year earlier by the San Francisco group, the Center for Biological Diversity--seeking to designate the fish as endangered under the Endangered Species Act. They also initiated a campaign to urge consumers to boycott the consumption of bluefin tuna in restaurants and in fish markets.

Instead, the federal agency designated the fish as a “species of concern” and said it will take new steps to further study the stocks and adjust the fishing effort.

In announcing the new designation, Eric Schwaab, assistant NOAA administrator for the fisheries service, said: “Based on careful scientific review, we have decided the best way to ensure the long-term sustainability of bluefin tuna is through international cooperation and strong domestic fishery management.”

In June, the federal fisheries agency set the bluefin tuna allocation for the coming year, which allowed expansion of the fishing season to more fishermen on the Eastern seaboard. The allocation also permitted the continuation of longline fishery, which because of its indiscriminate methods has drawn the concern of environmentalists for years. Conservation groups, including the San Francisco center and Coastal Conservation Association, responded that rule changes will continue to put the fish in greater harm.

According to the suit: “The Final Rule loosens controls on fishing for bluefin tuna. Specifically, it increases retention limits and lengthens the fishing season.”

Catherine Kilduff, an attorney for the biological diversity center, said that years ago, anglers went fishing for bluefin tuna off Cape Cod, and the season was but a few months long. The fishermen caught the biggest of the fish and the quota would be closed. Through changes in management, fishermen are now allowed to pursue the fish for months, during the fall and winter when the tuna begin their winter migration to southern waters. Fishermen can now pursue the fish continuously as they migrate all the way down to Florida. They spawn in the Gulf of Mexico in spring. The fishing season ends now on the last day of March.

“This rule enables fishermen to chase the remaining bluefin tuna down the Atlantic Coast on their way to reproduce in the Gulf of Mexico,” she said. “At some point, the last bluefin tuna will be caught, and there’ll be no fishery left at all.” Despite efforts to conserve the fish by her organization and others, she said: “It is very frustrating they are still increasing fishing for tuna, when there is such an obvious problem.”

According to the complaint, “The Final Rule for the 2011 Atlantic bluefin tuna regulations...is arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with the law, in violation of the Administrative Procedure Act.”

Further, Mrs. Kilduff said even in the best of circumstances, the management process is so slow, it will take more than a year before the federal agency can take any additional action to protect tuna.

Most commercial rod and reel fishermen in this region fish east and south of Chatham for the adult sized bluefin tuna. Some bluefin tuna fishing was done in the waters south and east of the Vineyard during the warmest days of last summer. They caught fish from 20 to 40 miles south of the Island, mostly south of Noman’s Land.

And there were reports that recreational anglers did catch small 20- to 30-pound bluefin tuna, at “The Hooter,” a buoy that marks the Muskeget Channel, which is south and east of the Vineyard.

“Western Atlantic bluefin have declined by more than 80 percent since 1970 due to overfishing,” according to the center Web site. “The Fisheries Service’s latest rule nearly doubled 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.”

Even though Vineyard anglers may feel comfortable with the current management regimen for bluefin tuna, Mrs. Kilduff warns there are fewer fish out there, and soon enough all anglers will suffer from the decision.

Years ago, highly pelagic swordfish were harpooned off New England by local fishermen. Through changes in management, the fishing effort and harvesting moved south to southern states where the fish spawn. Now, very few fishermen see swordfish in these waters. Most of the fishing has shifted to southern waters.

The problems with bluefin tuna, according to the center, are further exacerbated by the fishing authority that oversees all bluefin tuna fishing in the Atlantic, the International Commission for the Conservation of Atlantic Tunas (ICCAT). The organization oversees the fishing management of member countries. Mrs. Kilduff said there is large-scale overfishing of bluefin tuna on the eastern side of the Atlantic.

Greenpeace, a worldwide ocean conservation group that is often fighting for protection of whales and marine mammals, has long campaigned for better worldwide management of bluefin tuna, more specifically in the Mediterranean.

Even though ICCAT is allowing substantial overfishing on the eastern side of the Atlantic, Mrs. Kilduff said it is no excuse for the United States not taking a more conservative approach.

Last July the International Union for Conservation of Nature and Natural Resources, in updating their “red list,” put bluefin tuna in the critically endangered category. Writes the Union: “Bluefin tuna: The western Atlantic stock has experienced severe declines in the past, is also below maximum sustainable yield, and has not recovered under current fishing regimes. Management of the eastern Atlantic stock is essential to the future of this species, as it represents the majority of this species global population.”

The Center for Biological Diversity may be found on the web at bluefinboycott.org.