AUGUSTA — A legislative committee has endorsed a measure that would open most of the St. Croix River to alewives, a small schooling fish, by the end of this month.

L.D. 72 received unanimous support from the Marine Resources Committee on Monday. As an emergency bill, it needs two-thirds approval from the full House and Senate and would take effect immediately. The votes could come as early as Wednesday.

The bill would end the state’s 18-year blockade of the fish, allowing spring runs of alewives through the fishway at the Grand Falls Dam near Princeton and through much of the St. Croix watershed.

Scientists expect alewives’ numbers to increase from tens of thousands to 10 million or more, and predict benefits for the St. Croix and eastern Maine marine ecosystems.

“It’s the right thing to do for Maine, it’s the right thing to do for the (Indian) tribes, it’s the right thing to do for the fish,” said a visibly pleased Jeffrey Pierce, executive director of the Alewife Harvesters of Maine. “It will create food to help bring back cod and haddock and silver hake and pollock.”

The bill is bitterly opposed by fishing guides from interior Washington County, who fear alewives will harm smallmouth bass. Don Kleiner, executive director of the Maine Professional Guides Association, said he was “disappointed,” but had no further comment Monday.

Alewives, also known as “river herring,” spend most of their lives in the ocean, but swim up freshwater rivers in spring to spawn.

An important source of food for larger fish, the alewife population crashed after dams were built on Maine’s rivers in the 19th century.

After fishways were built and pollution was reduced in the early 1980s, the annual run grew 13-fold, to more than 2.6 million.

In 1995, however, Maine legislators passed a law at the behest of fishing guides that ordered the fishways at the Woodland and Grand Falls dams closed to the fish, whose run fell to just 900 fish in 2002, a decline of 99.7 percent.

The Legislature revisited the issue in 2008, but ultimately decided to open only the Woodland Dam in Baileyville to the fish, depriving them of an estimated 94 percent of their habitat.

L.D. 72, sponsored by Passamaquoddy Rep. Madonna Soctomah, would effectively undo the 1995 and 2008 laws, letting the fish pass through the two dams.

It has the support of lobstermen, groundfishing interests, environmental groups, Indian tribes and the U.S. and Canadian governments, which share sovereignty over the watershed straddling the Maine-New Brunswick border.

Canada has made it clear that it intends to let the fish pass the upstream Vanceboro dam, which Canada controls. That would give the fish access to the entire eastern branch of the watershed. On the western branch, the alewives would have access as far as West Grand Lake Stream dam.

“Many of my colleagues in New Brunswick will be very happy when they hear this news,” said John Burrows, director of New England programs for the Atlantic Salmon Federation. “They have been upset for two decades by the unilateral action of Maine in closing the St. Croix.”

The Marine Resources Committee unanimously rejected the LePage administration’s compromise proposal to allow a phased reintroduction of the fish.

A third measure, similar to L.D. 72, also was rejected.

Scientific studies have shown alewives and smallmouth bass successfully cohabit dozens of lakes, ponds and rivers in Maine.

“It’s nice to see the science come out a step ahead of the politics and help make a good decision for the watershed and for the fish,” said Theodore Willis, a research scientist at the University of Southern Maine.

Colin Woodard can be contacted at 791-6317 or at:

cwoodard@pressherald.com