August 11, 2021

Protecting Eels is One Goal of the County’s Efforts to Help ‘Stream Critters’ During Water Quality Month

American eels are the only fish found in the Montgomery County area that begins life in seawater (Bahamas and Bermuda area) and travel to freshwater streams for adulthood. During its campaign to protect at-risk stream critters during National Water Quality Month in August, the County Department of Environmental Protection (DEP) eels are among the at-risk stream critters that DEP is working to ensure their survival.

The American eel is a smooth, snake-like fish with a greenish, yellowish-brown or blackish body. It lives in rivers, streams and other freshwater areas throughout the Chesapeake Bay watershed. Eels live long and grow quite large. Females, which can spend 20 years in freshwater before undertaking their long spawning migration to saltwater, reach 52 inches and may exceed seven pounds. Although they do bite, eels are nonvenomous.

The American eel has a greenish, yellowish-brown or blackish body with a whitish belly. Its continuous fin stretches around its rounded tail from its back to its belly. The eel feeds at night on worms, small fish, clams and other mollusks and crustaceans, such as soft-shelled crabs.

According to the Chesapeake Bay Program website, eels are “catadromous,” meaning they live in freshwater rivers and spawn in the ocean. In October, sexually mature eels swim out of the Chesapeake Bay to the Sargasso Sea, an area of the Atlantic Ocean east of the Bahamas. In January, the eels spawn there, then die. Tiny eel larvae drift in the ocean for nine to 12 months. During this time, larvae transform to the “glass eel” stage. Ocean currents carry the transparent glass eels thousands of miles to the U.S. coast. Before entering the Bay, the glass eels become pigmented. These brown eels, called elvers, are only about 2.4 inches long. Some elvers stay in the Bay, but most continue to swim many miles up the Bay’s rivers to freshwater. After a few months, the elvers transform into the adult “yellow eel” stage. Adults remain in freshwater rivers and streams for the majority of their lives. Once they reach sexual maturity, they return to the Sargasso Sea to spawn and die. American eels usually live for at least five years, though some eels can reach 15 to 20 years old.

“Water is essential to life, but far too often we take clean water for granted," said County Executive Marc Elrich. "I appreciate our Department of Environmental Protection's innovative efforts to promote National Water Quality Month by highlighting the immediate danger poor water quality has on our ecosystem. We need to minimize pesticides and other runoff into our waterways and we need people to understand the importance of cleaning up our waterways.”

Throughout August, DEP will be releasing a series of blogs and videos on social media and on highlighting unique stream critters such as the eel. The series will focus on their histories, what makes them unique, how residents can help protect them and DEP’s approach to improving their habitats. 

“There is a direct connection between the quality of water in our streams and wildlife,” said DEP Director Adam Ortiz. “Clean water allows for wildlife to thrive and flourish. Unfortunately, pollutants, pesticides, and even pet waste that wash from our streets and lawns flow into our County creeks and streams. The result is stream critters that should be thriving, but instead are at risk because of human actions.”