Scientists: Remove dams to help fish
pressherald.com
By MEREDITH GOAD, Portland Press Herald Writer
Remove the dams. That's the top recommendation of the National Research Council in a new report that examines strategies for restoring the endangered Atlantic salmon in Maine.
Priority should go to downstream dams that, if removed, will open up the greatest amount of habitat for salmon, the report said.
Restoring natural river flow wherever possible is one of three "urgently needed actions" identified by the independent panel of researchers who wrote the report.
The scientists also suggest the state begin an experimental program of adding lime to rivers and streams to neutralize water chemistry that has become so acidic it is killing young salmon as they move from freshwater to the ocean.
And hatcheries should be used sparingly, the report says, to supplement wild salmon populations and serve as a genetic storehouse of fish from different rivers.
The report stops short of detailing exactly how these goals should be reached, leaving room for "a lot of thinking and expertise," said Lewis Incze of the Bioscience Research Institute at the University of Southern Maine, who was a member of the panel.
"We don't spell out which dams should go, and we don't say they absolutely should go," Incze said. "We're saying dams remain one of the things we can manage that are a primary obstacle to the return of salmon . . ."
The report does say emphasis should be put on the Penobscot River because that is where most of the remaining wild salmon live.
Maine's Atlantic salmon was listed as a federally endangered species in eight Maine rivers in November 2000. Once a vibrant fishery, Atlantic salmon delighted generations of anglers and was an important part of the Penobscot Indian culture for hundreds of years. But now salmon populations have declined to alarming levels. In 2002, just 871 salmon returned to spawn in Maine rivers.
During the controversy that followed the endangered species designation, Maine's congressional delegation asked the National Research Council, the principal arm of the National Academy of of Sciences, to help answer the question of whether Atlantic salmon in Maine rivers are genetically distinct from salmon bred in captivity.
That question was answered in a report published in January 2002 that determined Maine salmon are indeed unique. The final report released Tuesday offers options for helping the population recover.
Conservationists and state officials working on salmon restoration were largely pleased with the report. They said it validates actions already being taken by the state, such as the proposed removal of two of the four dams on the main stem of the Penobscot River.
"The focus on the Penobscot River confirms what all of our groups believe - that the single most important thing that can be done for Atlantic salmon is to restore the Penobscot River," said Laura Rose Day, director of the Penobscot River Restoration Project, a coalition of conservation groups and the Penobscot Nation.
The National Research Council estimates a dam-removal program could cost between $300,000 to $15 million annually, assuming three to five dams are removed each year, but others said that seemed low. The purchase of the Penobscot dams is expected to cost $25 million, plus another $20 million to $25 million to complete the project.
The liming project may cost $100,000 per stream initially, the report said, followed by another $50,000 to $100,000 a year for each stream treated.
The Baldacci administration is already drafting legislation that would allow the liming project to go forward, according to Dick Davies, a senior policy adviser to the governor. The bill should be submitted to the Legislature within the next week or two.
Pat Keliher, director of the Atlantic Salmon Commission, said the first river to be treated may be the Dennys.
"This type of work is being done in many different places," he said. "It's being done in Nova Scotia, it's been done in Norway, it's been done in some southern states with trout waters, and there's been a lot of success associated with it."
Keliher said he also liked the panel's recommendation that Maine hatcheries re-evaluate their stocking strategies.
"Having a hatchery in place to just produce a lot of fish may sound great, but maybe we can produce fewer fish that are better quality," he said. "We need to cut to the chase and say OK, what is the best for the fish that we're producing? I think that was one of the recommendations that was really right on target."
Keliher wasn't happy, however, with a recommendation that the salmon fishery remain closed to recreational fishing. Keliher has floated the idea of reopening the Penobscot to a limited catch-and-release salmon fishery, "if it can pass a straight-faced scientific test."
The National Research Council also recommended other actions designed to reverse the decline of salmon populations in Maine, including:
Don't stock Maine's streams with salmon or non-native fish that may out-compete wild salmon.
Curtail research that increases the risk of death to wild fish.
Make more of an effort to stop the escape of farmed salmon that pose a threat to wild fish.
The report also includes recommendations that carry broad environmental benefits, such as better water-quality monitoring and the creation of forest buffer zones. Such measures ensure that even if the Atlantic salmon does go extinct, "we've given back to the natural system some of those things we took away," Incze said.
"I do think it's possible that whatever else we do here, climate change may actually put an end to the salmon," he said.
Incze said the next step should be putting together the expertise the state needs to take salmon restoration to the next level.
"We would like to save the salmon, and we do know that can't be done everywhere," he said. "Where do we have our best chances of doing that? You need to put together a serious team of people to answer those questions." |
