Expert Panel Casts Dire Warning for Maine's Salmon

WASHINGTON, DC, January 22, 2004 (ENS) - Maine's once abundant Atlantic salmon are nearing extinction and will not survive without a comprehensive restoration effort, warns a report released Tuesday by a federal panel of experts. The report by the National Academies calls for a program of systematic dam removal along with efforts to improve water quality and limits on the use of hatcheries in order to save Maine's wild salmon.

The decline of Atlantic salmon populations in Maine "has been pervasive and substantial over the past 150 years, bringing them close to extinction in recent years," said Michael Clegg, chair of the committee that wrote the report and a professor of genetics with the University of California at Riverside.

Populations of Atlantic salmon have declined from an estimated half million adult salmon returning to U.S. rivers each year in the early 1800s to perhaps as few as 1,000 in 2001.

Atlantic salmon were listed in 2000 as endangered under the federal Endangered Species Act.

"There is an urgent need to reverse the decline of salmon populations in Maine if they are to be saved," the committee wrote.

Removing dams such as the Veazie on the Penobscot River is key to restoring Maine's Atlantic salmon. (Photo courtesy Maine Atlantic Salmon Commission)

"Although salmon have declined over much of their natural range in Europe and North America in recent decades, suggesting that some factors affecting them operate over large areas, the severity of declines in Maine warrants special attention," the committee wrote. "Maine's rivers and streams once had the capacity to support much larger salmon populations than they do now, so the potential exists to substantially increase the populations of wild salmon in Maine."

The committee found that dams appear "to be the single most important class of impediments to salmon recovery that can be influenced by human actions in the short and medium terms."

The report says that some of the dams in question are no longer economically viable and estimates removal costs to be between $300,000 and $15 million per year. The figure assumes a cost ranging from $100,000 to $3 million per dam and the removal of three to five dams per year.

The committee calls on the state to continue focusing recovery efforts on the Penobscot River, which boasts some 90 percent of Maine's returning salmon population. It hailed an agreement forged last year by a coalition of interests to remove the two lowermost dams on the river - some 20 dams operate in the watershed.

The acidification of Maine's rivers and streams is another threat to the salmon, according to the report. Sulfates and other chemicals are altering water quality and may be increasing mortality among fish making the transition from fresh water to salt water.

The panel calls for immediate trials of a procedure known as liming, which is the addition of limestone to rivers and streams to counteract acidification in streams.

Estimates of the initial cost of liming each stream would be around $100,000, with subsequent costs of $50,000 to $100,000 per year for each stream treated.

Maine has developed a heavy reliance on using hatcheries to increase its salmon population, but the panel says this practice should be used sparingly.

Stocking rivers with hatchery raised salmon remains an unproven way to boost the fish population, according to the committee, and additional research and scientific guidance are needed.

"The evidence from over 130 years of stocking leads to the conclusion that hatchery production has not rescued Atlantic salmon in Maine," the report says. "Reliance on hatcheries as the sole or primary intervention will not be sufficient to prevent extinction for very long."

Hatcheries are not the answer to restoring Maine's wild salmon, according to the report. (Photo by Beth Jackson courtesy U.S. Fish and Wildlife Service)

The report suggests that hatcheries primarily be used to preserve the genetic diversity of remaining wild salmon populations by providing them with a secure place to grow if necessary.

"Aquaculture also appears to have an important and generally adverse effect on wild salmon populations," the committee wrote.

The panel of experts recommended the continuation of a ban on fishing of Atlantic salmon in Maine, improved monitoring of water quality, and better efforts to prevent farmed salmon from escaping.

In addition, they called on Maine to avoid stocking its streams with salmon or nonnative fishes that may mate with or crowd out wild salmon, or out compete them for food.

Climate change also appears to be playing a role in the fate of Maine's salmon, the committee wrote, and "the question arises as to whether the climate changes are so great that attempts to restore salmon are futile."

"The committee cannot answer that question but there is no doubt that the changes make it more urgent to improve other aspects of their environments," according to the report.

The National Academies is a private, nonprofit institution that provides science and technology advice under a congressional charter.

The full report can be found here.