Let’s Not Shatter the Glass Eel

By Dr. John Waldman and Dr. Merry Camhi

With the exception of sushi aficionados devouring unagi in rolls of avocado, rice, and a dab of wasabi, American eels do not get a lot of love today. Once a dietary mainstay of native peoples and early colonists, these nutritious animals have been devastated over the centuries by growing fishing pressure and the construction of dams along rivers where they once swam in abundance.

Although a petition to add the American eel to the U.S. endangered species list was denied in 2007, a second petition will be considered in 2015. In the meantime, fishery managers can take critical steps to secure a better future for what many consider the most mysterious fish in the sea.


American eels lead a singular existence of sweeping geographies. Spawned deep in the Sargasso Sea—a two million-square mile becalmed region of the Atlantic between the Azores and West Indies—their larvae hitch a hemispheric ride for half a year on the Gulf Stream as they transform into ‘glass eels.’

Julie Larsen Maher 8760 Glass Eel 06 15 11
By Julie Larsen Maher

Each spring, millions of these transparent, four-inch-long baby eels exit the Atlantic to enter estuaries and rivers from Greenland to northern South America. Once in fresh water they darken, drive upstream, and spend the next decade or two maturing, until the spawning imperative stirs them to migrate thousands of miles back to the Sargasso, where they reproduce just once and die.

For millions of years this unique life cycle was wildly successful. In the 1800’s, eels that had migrated  up the St. Lawrence River and into Lake Ontario aggregated at the foot of Niagara Falls. Nineteenth-century naturalists commented that “hundreds of wagonloads . . . would hardly be considered excessive by those who have visited the spot.”

Only a few decades ago Lake Ontario held five to ten million eels. Today some 84 percent of their historic habitat in East Coast watersheds and the Lake Ontario Basin is no longer accessible due to dam construction. Before the Conowingo Dam blocked almost the entire Susquehanna River, nearly 1 million pounds of eels were caught annually. By 2000, they fell to zero.

elvers in ME 6-13
Eels for sale in Maine

In recent years, glass eels have been undertaking a migration of another kind: Caught in nets as they enter East Coast tributaries, live eels are sold and shipped half way around the world to aquaculture pens in China, where they are fattened up for the Japanese sushi markets.

With relentless fishing, dams, habitat loss, and pollution American eels now find themselves “at or near historically low levels” according to a 2012 scientific assessment.

It’s as bad in Europe. By the end of the twentieth century, the number of glass eels entering rivers there declined to 1 percent of historical numbers. To fuel their recovery, the Convention on International Trade in Endangered Species (CITES) banned the export of all European eels – hence the Chinese imports of American glass eels for their aquaculture pens.

The Atlantic States Marine Fisheries Commission, charged with managing shared fishery resources in U.S. waters, will soon decide on new regulations for the American eel, including closure of all glass eel fisheries along the East Coast. They are currently legal only in South Carolina and Maine (other states closed their fisheries to spur recovery).

In the wake of European and Canadian glass eel fishery closures, the price per pound for American eels jumped ten-fold in the past decade, reaching as high as $2500 per pound. This has led to a veritable gold rush in Maine, with fistfights, thefts of catches, and considerable poaching in other states.

American eels need relief, not intense fishing of young eels that are the future of the species. In 2007, Ontario put the American eel on its Endangered Species List, and Canada declared it Threatened in 2012. The European eel is now Critically Endangered.  Just this February, Japan listed its own Japanese eel as Endangered. Eels worldwide need more friends.

It’s time for the Atlantic States Marine Fisheries Commission to step up to protect the American eel here in our own waters. At their August 7 meeting, rather than bow to pressure to open fisheries in other states, the Commission should vote to close all glass eel fisheries to give this once bountiful and still mysterious species relief before it’s too late.


Dr. John Waldman is Professor of Biology at Queens College  and the author, most recently, of Running Silver: Restoring Atlantic Rivers and Their Great Fish Migrations. Dr. Merry Camhi directs the New York Seascape Program at the Wildlife Conservation Society’s New York Aquarium.



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