Eels part 2: Growing Up

By Jason Beale, Manager, Abbott’s Mill Nature Center

On June 4th DEEC Manager, John Harrod, posted a blog on American Eel elvers.  Elvers, defined as being less than 6″ long, mature into “yellow eels” as they grow and work their way up freshwater streams like Johnson’s Branch at Abbott’s Mill Nature Center.  Eels are catadromous fish, meaning that they breed in saltwater (Sargasso Sea) and migrate into freshwater to spend the majority of their adult lives.  For comparison, Shad and Salmon are anadromous fish, breeding in freshwater, but living in salt water.

Despite the drought-impacted water levels (1-3″ in many sections), American Eels are conspicuous nocturnal residents on Johnson’s Branch during warm summer nights.

Johnson’s Branch is one of the two main streams feeding the Mispillion River in Milford.  In actuality, the river becomes a series of mill ponds as one heads upstream from Milford.  Therefore, an eel at Abbott’s Mill has had to migrate at least 3.5 miles from Milford and over or around 3 dams.  Elvers can and do leave the streambed on occasion to cross obstacles.

A “Yellow” Eel in Johnson’s Branch. This individual kept it self stationary in the current for at least five minutes until I spooked it, quickly disappearing into the stream edge roots and debris.

On July 2, under the light of the full moon, I took a slow walk along the Johnson’s Branch boardwalk at Abbott’s Mill and encountered at least 4 different American Eels, ranging in size from ~12-24″.  The American Eel story becomes more fascinating as the adults morph into “Silver Eels” and prepare for their journey to the Sargasso Sea, but that’s a tale for another blog…


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