Potomac passageways to aid upstream migration of eels

HAGERSTOWN, Md. — The Potomac River is being readied for a starring role in the restoration of the American eel to Eastern U.S. waterways.

By the end of this year, fishery biologists hope to complete passageways for upstream eel migration around two dams that the National Park Service owns. The proposed eelways would open up 120 miles of “the nation’s river” as a habitat for eels, which once accounted for a quarter of all aquatic life in the Chesapeake Bay watershed.

The projects at dams four and five in the Chesapeake and Ohio Canal National Historical Park are the latest in a series of eelways planned or already built in the Chesapeake Bay watershed, which holds the greatest abundance of eels along the East Coast.

Eel populations have diminished, though, prompting the U.S. Fish and Wildlife Service and the National Marine Fisheries Service to consider whether they should be protected under the Endangered Species Act. The agencies will publish the results of their two-year review in the Federal Register this month, said David Sutherland, a marine biologist in the Annapolis office of the Fish and Wildlife Service.

The national commercial eel harvest was less than a million pounds in 2005, down from about 3.5 million in the mid-1970s, federal officials say.

Mr. Sutherland said dams are thought to be one factor in the decline of the snakelike fish, which historically were a dietary staple for American Indians and early settlers. The dams obstruct young eels’ 1,000-mile journey from their birthplace in the Sargasso Sea, an area of warm water in the middle of the Atlantic Ocean, to the freshwater rivers of North America. Eels return to the Sargasso once before dying to spawn but spend most of their lives — up to 24 years — in brackish and fresh waters. They have been found in every state east of the Rocky Mountains, Mr. Sutherland said.

“By providing passage, we’re bringing them back to historical habitats where they’ve existed for a long time,” he said. “It’s a wonderful story, a restoration story. We’re looking to open up the entire main stem Potomac as well as its tributaries.”

Eelways are essentially 24-inch-wide ramps with rough-textured bottoms that help give the slithering creatures traction during their moonless night migrations. Many eelways have been built in Massachusetts and Maine but there were none in the Chesapeake watershed until 2004, when Allegheny Energy Inc. paid $75,000 for an eelway on the Shenandoah River at its Millville, W.Va., hydroelectric plant. Another was built last year at Allegheny’s Warren, Va., hydroelectric plant on the Shenandoah, a Potomac River tributary.

Maryland’s first eelway was installed in August on at a 10-foot-high dam on the Unicorn Branch, a Chester River tributary in Queen Anne’s County.

Allegheny Energy, based in Greensburg, Pa., is funding the Potomac River eelways and three others planned for the Shenandoah in Virginia at Luray, Newport and Shenandoah. All told, the company has committed about $1 million to eel migration and related studies under an agreement with federal regulators.

“We felt it was important to protect them and help them breed,” Allegheny spokesman Michael Grandillo said.

At the Potomac dams, which date to 1834, care will be taken to retain the scenic integrity of the national park, officials said.

Mr. Sutherland said overfishing of American eels, mostly for export to Europe and Asia, is also thought to have contributed to the drop in numbers. The creatures are netted in river mouths in their translucent larval stage in the spring and served as glass eels. Yellow juvenile eels, called elvers, are used for sushi and sell for about $600 a pound, Mr. Sutherland said.

Adult eels can easily reach 3 feet in length and are eaten by some Potomac River anglers who catch them during their downstream migration in the fall.