Wildlife of the James

The Amazing American Eel
Anguilla rostrata

By Gabe Silver, JRA Environmental Educator

On this winter’s day, let’s abandon the cold banks of the James and journey southeast. If you would, step aboard a flight that will carry us over Bermuda and out over a million square miles of warm, calm ocean water known as the Sargasso Sea. Bordered by ocean currents like the Gulf Stream but without actual shores, this protected sea supports the growth of Sargassum algae, which in turn supplies food and habitat to many species of the ocean’s fauna, such as white marlin and hawksbill turtles. We are here to search for a particular serpentine fish with a close connection to rivers like the James. We are hoping to see something which has never been observed by human eyes, something only guessed at based on the discovery of tiny larval fish found in these waters. We are looking for the amazing American eel.

To understand why we have taken the trouble to journey so far, let’s return to a small tributary stream of the James River in the early fall. Here, in the darkness of night, a mature female eel is feeding actively on crustaceans and small fish, using her unique snake-like body to capture prey in places other predators can’t access. After a freshwater life of up to 18 years, she has grown to a length of over 4 feet and has begun storing up fat reserves for a very long swim. Departing in October, she will carry hundreds of thousands of eggs inside her body toward the Sargasso Sea. As she leaves the James her body will change; her body re-coloring itself for the ocean, her eyes able to perceive more blues, and her digestive organs degenerating, as she will never again feed.

Illustration by Duane Raver/USFWS

How and where the American eel reproduces was a mystery until 1922, when after 20 years of research, Johannes Schmidt found that the smallest larval eels occurred in samples from the Sargasso Sea. It has since been accepted that eels from all East Coast rivers and estuaries congregate and spawn here in the winter. But no one has actually observed this activity or documented what becomes of the adult eels after the spawn. It is known that they do not return to freshwater, and it is assumed that they die.

If we were to drop you off here with a well-provisioned raft, you could continue to journey with the life-cycle of the eel. The tiny larval eels resulting from the spawn will drift passively in the ocean currents for nearly a year before metamorphosing into clear, free-swimmers of about 2 inches known as glass eels. As they begin to actively migrate toward the coast and upriver, they will darken into a form known as “elvers” before reaching the juvenile stage of “yellow” eels in which they will spend most of their lives. Males tend to stay nearer the ocean, grow smaller and mature and reproduce sooner. Females grow larger by spending long lives feeding upriver where population density is low. Upon sexual maturation, eels undergo a final metamorphosis into “silver” eels and soon depart for the sea.

While the eel is often spurned in the U.S., it is considered a delicacy in parts of Europe and Asia. Catching eels for export is lucrative in some areas and puts pressure on eel populations already effected by the great enemy of the eel-dams. Dams on the James River have affected many fish species, and the American eel is no exception. The number of dams historically placed on the middle and upper James gradually wore down the eel population. Work on improving fish passage has re-opened access to much of the watershed, and eels have begun to turn up in greater numbers upriver of Richmond. Many more dams that no longer serve a purpose present many opportunities to restore this fascinating creature’s habitat.

Learn more:

More Eel Information

A Plea for the American Eel

Is the Eel Endangered?

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