Where did all the eels go? Why the Potomac River needs this slippery friend.

Eels carry a secret weapon for cleaning water, making them more important than once thought

image courtesy  of USFWS monitoring American eels in Buffalo Creek, Pa. 33, chesapeake bay program flickr

image courtesy of USFWS monitoring American eels in Buffalo Creek, Pa. 33, chesapeake bay program flickr


Coming soon to a river near you: eels, and lots of them if everything goes according to plan.

Centuries ago the Potomac teemed with eels. They were a staple food source of George Washington and Abraham Lincoln’s armies.

But for the last 100 years or so, eels have been all but absent from the upstream waters of the Potomac River. The culprit? A hydroelectric dam originally constructed to divert water in the C&O Canal near Shepherdstown, West Virginia. The dam interrupts the eels’ lifecycle, making it extremely difficult for the species to thrive and survive in the Potomac.

American eels are born in the Atlantic Ocean and migrate into freshwater rivers to mature before returning to the ocean to spawn. Dams, like the one near Shepherdstown, prevent them from swimming upriver. (Interestingly, the eel’s migration pattern is the opposite of American Shad, a native fish that has been successfully restored to the Potomac River. Shad swim from the ocean into freshwater rivers to spawn. Eels do the opposite.)

As creepy as they may seem, eels are actually a river’s best friend! Eels are an important and beneficial part of a healthy river ecosystem.

For starters, eels are an important food source to larger fish and fish-eating birds such as bald eagles. And from a water quality standpoint, eels play an even more important role as a natural taxi service of sorts. Eels transport freshwater mussels, which filter pollution from the water. Without eels, mussels can’t get around, which means dirtier water wherever they aren’t.

Restoring eels, and by extension mussels, could make the Potomac "crystal clear," David Sutherland, a biologist with the US Fish and Wildlife Service told WUSA 9. Here’s an example of what mussels can accomplish:

A new effort is underway that will help restore eels to the upstream waters of the Potomac River. To allow eels safe passage through the Shepherdstown dam, scientists from the US Fish and Wildlife Service are tracking their movements to determine where they try to pass. Once they figure out where the eels naturally swim, they will construct a special passage over the dam, which will allow the eels to get upstream. They expect project to be complete by next spring.

So be on the lookout for eels, and if you spot one, don’t grimace. Remember, eels are a good thing!


Get local wildlife and river news delivered to your inbox.

Sign up to receive our monthly
River Update email

Name *

100% Privacy. We don't spam or share your information. 


You May Also Like