Eelways help eels live full lives

July 17, 2002|by ANDREA ROWLAND

Construction of two "eelways" at Dams No. 4 and No. 5 in the Potomac River near Clear Spring and Williamsport will make the task of swimming upstream less slippery for American eels.

Allegheny Energy is funding the $150,000 project as part of a dam usage agreement with the U.S. Department of the Interior.

Dams block eels' passage to important aquatic habitats, such as portions of the Potomac River.

The eelways, or eel ladders, are ramp-like structures that will be attached to Dams No. 4 and No. 5 to make upstream migration easier for eels, according to Kathy Reshetiloff of the U.S. Fish and Wildlife Service.


The eelways will enable more eels to swim upstream, where many will live for decades before beginning their long journey back to the Sargasso Sea, a 2-million-square-mile section of deep, algae-riddled water adrift in the central North Atlantic.

Female American eels spawn and then die in the Sargasso Sea between August and December, according to Reshetiloff.

Ocean currents then carry the eel hatchlings, which look like transparent ribbons, to the Chesapeake Bay and other Atlantic Ocean inlets - a trek that can take months or years, Reshetiloff said.

The hatchlings become tiny, unpigmented eels, or glass eels, after about a year. They begin to turn dark brown as they swim through coastal waters, and these "elvers" then wiggle their way upstream into brackish and freshwater streams, rivers and creeks, Reshetiloff said.

Elvers go through a growth spurt when they stop migrating, turning into yellow eels. These mature eels live eight to 24 years in the bay and its tributaries - feeding mostly at night and burrowing into mud and other cover by day - before reaching sexual maturity and swimming downstream to spawn, Reshetiloff said.

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