Maine’s state legislature is getting ready to debate an emergency bill that could see the St. Croix River re-opened this spring to gaspereau, ending a controversy that has spanned almost 20 years.

The U.S. Environmental Protection Agency struck down the 18-year-old state law last year that has blocked the St. Croix River against the wishes of the Canadian government and environmental groups.

The agency ruled that Maine is violating the Clean Water Act by blocking a native fish from entering the river.

There are now three competing bills going before the state legislature to replace the law, each law proposes its own timeline for opening up the river to gaspereau.

'I hope it's not a party issue because I think it really has to do with science.'— Landis Hudson, Maine Rivers

The first bill is being sponsored by the Passamaquoddy tribe and would see a prompt re-opening of the river.

Landis Hudson, the executive director Maine Rivers, an environmental group, said she hopes that bill will receive bipartisan support in the legislature, so the river can be opened up by May 1.

"I hope it's not a party issue because I think it really has to do with science,” Hudson said.

Paul Bisulka, who helped draft the proposed law, said he hopes the bill can be approved so the fish can be moving up the river later this spring.

"We want the fish now. We want it unrestricted and we want those river herring to move all the way up into Indian territory,” Bisulka said.

But the process could take much longer, depending on which bill is approved by the state legislature.

A second bill favoured by Gov. Paul LePage would limit the number of gaspereau allowed upriver and that proposal would delay the start until 2014.

'Just a matter of time'

Despite the debate over timelines, one New Brunswick group is taking solace in the fact the river blockade will be ending soon.

Geoff Giffin, a director with the Atlantic Salmon Federation in New Brunswick, said he hopes the fish can start moving up the St. Croix River in the near future.

"It is at this point just a matter of time, hopefully sooner,” he said.

The state began blocking the river to gaspereau in 1995 after bass anglers complained they were hurting their sport.

Gaspereau are an important source of food for groundfish like cod and haddock and must travel up rivers to spawn.

The state's law horrified environmentalists and was passed against the wishes of Canada.

The International Joint Commission, a panel designed to resolve water disputes on waterways shared by Canada and the United States, had been trying to mediate the dispute in 2011.

The federal environmental protection agency ruled on the Maine law as a reaction to court challenges launched against the federal government by environmental groups in New England and in Maine.

When Maine blocked the river to gaspereau in 1995, there were more than two million of the small fish in the river. The fish population has dropped significantly since the state's actions.