An environmental group has filed a lawsuit against the state of Maine, opening a new round in the fight over the future of alewives in the St. Croix River, which separates Washington County from New Brunswick.

The move by the Conservation Law Foundation comes after this summer’s legal sparring between the U.S. Environmental Protection Agency and state Attorney General William Schneider over a controversial state law that ordered the fish passages at the Grand Falls dam in Woodland closed to the alewives’ spring spawning run.

In July, the EPA informed Schneider that this law violated the provisions of the Clean Water Act and directed the state to open the fishways. After consulting with Gov. Paul LePage, Schneider responded in August that the EPA’s directive was irrelevant, because the intention of the state law was to manage fish, not water quality.

The EPA, LePage and Scheider have had nothing further to say publicly on the issue in the months since.

Sean Mahoney, director of CLF’s Maine office, hopes the suit filed in U.S. District Court Monday afternoon will resolve the impasse in favor of the fish. It argues that the state’s position puts it in conflict with the U.S. Constitution, which states that federal law trumps state law when the two are in conflict.

This state law has the specific intent of preventing alewives from reaching their native habitat, and the Clean Water Act has the specific intent of restoring native fish like alewives to their natural habitat,” Mahoney said.

Informed of the suit by the Press Herald, the Attorney General’s Office did not immediately have comment.

The suit names two administration officials, marine resources Commissioner Patrick Keliher and inland fisheries Commissioner Candler Woodcock, as defendants.

If the past is any guide, the court will likely receive a response from the state and then issue a decision in the coming months.

Maine’s 1995 and 2007 alewives laws were passed at the behest of smallmouth-bass fishing guides, who fear that spawning alewives would harm bass populations. The 2007 law was opposed not only by environmentalists, but by fishermen, lobstermen, and the government of Canada, who argued that if alewife populations were restored, they would provide bait for fishermen and food for cod and other commercial fish species.

Prior to the passage of the 1995 law, 2.6 million alewives spawned in the St. Croix each year. After the state Legislature ordered the Grand Falls and Woodland dam fishways closed, the spawning population fell to 900 fish.

The EPA took up the issue in response to an earlier CLF lawsuit filed this past May. charging the federal agency with failing to enforce the act. The federal agency issued its directive to Attorney General Schneider the day after publication of a Maine Sunday Telegram story on the 17-year battle over the alewives’ access to the river.

In his response to the EPA, Schneider said LePage was committed to a compromise plan developed by the International Joint Commission, a US-Canadian body that resolves disputes on the international waterway. Under the plan a limited number of alewives would be allowed to spawn above Grand Falls, but enacting it will require that the legislature change the existing law.

Mahoney says the compromise plan is a farce, as it is based on the notion that spawning alewives will somehow harm smallmouth bass populations in the watershed, for which there is no scientific evidence. (Most studies suggest alewives boost smallmouth bass populations.)

“This plan isn’t a compromise, it essentially is the hostage to the irrational prejudices of people who have an economic interest in maintaining the smallmouth bass,” he says.

The Passamaquoddy – the native peoples of the watershed – strongly support restoration of the alewives to the river. On Sept. 27 their joint tribal council unanimously passed a resolution praising the EPA’s directive and demanding the state open the fishways.

“I won’t rest until I see the alewives swim to their ancestral spawning grounds unimpeded,” said Brian Altvater, a founder of Schodic Riverkeepers, a Passamaquoddy-founded group active in the issue.

If the court sides with CLF, Mahoney says that would compel the state to allow the alewives unimpeded access past the Grand Falls dam. It would not have bearing on the fishways at the next set of dams at Vanceboro (on the river’s east branch) and Grand Lake Stream (on the west), as these were built after the passage of the Federal Power Act, and therefore have never been in Maine’s jurisdiction.

“Those dams have fish passages and they were operating back [before 1995] when the Grand Falls dam was allowed to operate its passage,” Mahoney says. Presumably the dams could open their fishways immediately, giving alewives access to the entire watershed, he said.