BANGOR – Two organizations filed suit in federal court Monday to force Maine officials to take additional steps to prevent trappers from inadvertently capturing Canada lynx.

Last year, the Maine Department of Inland Fisheries and Wildlife settled a federal lawsuit by agreeing to ban larger foothold traps throughout northern Maine.

But the number of Canada lynx reported caught by trappers increased despite the new regulations. All eight of the lynx were released alive, but their mere capture is technically a violation of federal law because of the lynx’s status as a threatened species.

On Monday, representatives of the Wildlife Alliance of Maine and the Animal Welfare Institute argued they had no choice but to file another lawsuit to pressure DIF&W to take additional steps to protect lynx.

“Our Department of Inland Fisheries and Wildlife is in violation of the Endangered Species Act, a federal law,” Daryl DeJoy, executive director of the Wildlife Alliance of Maine, said outside U.S. District Court in Bangor.

“They continue to allow the incidental take of Canada lynx by state-sanctioned trappers and will not do what the federal government has asked and requires of them, and what the citizens of Maine want from them,” DeJoy said.

Representatives from DIF&W and the Attorney General’s Office declined to comment on the lawsuit. But a spokesman for the Maine Trappers Association said he believes the groups are using the lynx to attempt to ban all trapping in Maine.

“There’s no question that’s what this is about,” said Skip Trask. “I’m just a little surprised that the same people who were involved in the last lawsuit are back.”

Maine is home to the only self-sustaining population of Canada lynx in the eastern United States. Medium-sized cats, lynx are similar to bobcats but with longer legs and large, fur-covered feet that allow them to pursue prey in deep snow.

DIF&W biologists estimate there are at least 500 lynx in Maine, although there is concern that number may be falling because of a decline in snowshoe hares, their primary prey.

Last October, DIF&W officials and the Maine Trappers Association agreed to size restrictions on traps in northern Maine and to codify several other recommendations that trappers should follow to avoid catching lynx.

The settlement came after U.S. District Judge John Woodcock warned Maine officials that the state was likely liable for any lynx harmed during the state-regulated trapping season.

That lawsuit was brought by the Animal Protection Institute. Camilla Fox testified as an independent expert witness for the Animal Protection Institute. Fox is now a wildlife consultant for the Animal Welfare Institute.

DeJoy and the Wildlife Alliance of Maine were not party to last year’s lawsuit. But DeJoy did provide information to the Animal Protection Institute on lynx caught in traps.

Both Fox and DeJoy said last season’s trapping figures show more needs to be done.

“With eight lynx trapped in just 29 days, this means that on average at least one lynx is trapped every four days during the trapping season,” Fox said. “Again, these figures only include the lynx that are reported.”

Maine is applying to the U.S. Fish and Wildlife Service for what’s known as an “incidental take permit,” which would shield the state from liability whenever a lynx is accidentally trapped or killed. DIF&W has submitted several drafts to the federal agency, which has responded with suggested modifications.

Mark McCollough, an endangered-species biologist with the USFWS in Old Town, estimated that it would likely take up to a year to issue the permit once the state submits a final version. That means the permit will not be complete in time for this fall’s trapping season.

Walter Jakubas, who heads DIF&W’s mammal group, declined to comment on the lawsuit. But he said Monday that DIF&W staff carefully check trapped lynx for injuries before releasing them. Most of the lynx suffer only scrapes or minor swelling, he said.

The elusive lynx is easily the most controversial protected species in Maine. Last year, the USFWS exempted all of Maine from its critical habitat designation for the lynx but later revoked the entire rule amid a political meddling scandal.

The agency is developing a new critical habitat designation for the lynx. But again, Maine’s large commercial forest landowners are expected to seek an exemption on grounds that they already work cooperatively with state and federal biologists to protect lynx populations. Environmental groups are expected to fight an exemption.

The lynx also has figured heavily into debate over Plum Creek Timber Co.’s development proposal for the Moosehead Lake region, particularly for resort and housing plans near Lily Bay.