HONOLULU (AP) -- Environmentalists on Friday asked a federal judge to stop the National Marine Fisheries Service from allowing Hawaii-based fishermen to attribute some of the bigeye tuna they catch to U.S. territories.

They argue the agency is enabling the fishermen to circumvent international agreements aimed at controlling the overfishing of a popular tuna species known as ahi.

Earthjustice attorney David Henkin told U.S. District Court Judge Leslie Kobayashi the fisheries service acted illegally when it created a framework allowing Hawaii longline fishermen to record some of their catch as having been caught by fishermen in Guam, the Northern Mariana Islands and American Samoa.

"This is allowing them to fish without limits," Henkin said of Hawaii fishermen during a hearing in federal court for a motion Earthjustice filed on behalf of the Conservation Council for Hawaii and other environmental groups.

Bradley Oliphant, a U.S. Justice Department attorney who argued on behalf of the fisheries service, said the agency carefully studied the environmental effects of the quota transfer. He said the arrangement meets the requirements of U.S. fisheries and environmental laws.

The 26-member nation Western and Central Pacific Fisheries Commission, which regulates fishing from east and southeast Asia to waters around Hawaii, set a limit of about 3,500 metric tons for Hawaii longline fishermen this year. That's about 7 percent less than last year.

The National Marine Fisheries Service enforces these limits in the U.S. This year, the Hawaii fishery reached its annual limit in August, several months earlier than in the past.

The agency has also proposed rules that would allow Hawaii longline fishermen to bring in more bigeye tuna by shifting some of their catch to territorial fleets, which do not face the same limits from the commission.

In exchange, the Hawaii longline fleet would pay the territories money to support the development of local fisheries.

The agency has put similar rules in place in recent years after Congress, in a 2012 appropriations bill, directed the agency to create a quota transfer program. The late Sen. Daniel Inouye of Hawaii was Senate appropriations committee chairman at the time the bill was passed.

Lawyers in the case explained to Kobayashi their views on the validity of the agency's quota shifting rule, whether Congress' directive was still applicable or had lapsed and what federal fisheries laws require the agency to do.

Kobayashi gave the attorneys two weeks to file additional arguments.

The Western and Central Pacific Fisheries Commission counts major fishing nations such as Japan, Taiwan, South Korea and the U.S. among its members along with small island states such as the Marshall Islands. About 40 percent of the global supply of bigeye is caught in waters regulated by the commission.

Hawaii longline fishermen - who string long lines in the ocean from which they run shorter lines with baited hooks -account for only 1.6 percent of the bigeye caught in this region. U.S. purse seine boats also catch bigeye in the area. They use giant nets to surround and scoop up masses of fish.

Bigeye is one of two types of tuna known as ahi. The other is yellowfin.