Thursday, August 18, 2011

Adirondack Fish: American Eel

The mysterious, unique, native populations of the American Eel (Anguilla rostrata) have drastically declined in the Adirondacks from historic populations. Surprisingly, individuals can still be found in tiny creeks buried in gravel and mud or under rocks. It has been recommended that the American eel be placed on the Endangered Species list due to alterations to migration routes and loss of habitat, mainly caused by dams along the migration routes.

American eel’s are elongate and very flexible. They have no pelvic fin and their anal and dorsal fins are joined forming one fin that runs around their body. The mouth is terminal, with a projecting lower jaw.

Eels are catadromous, meaning they live most of their adult life in freshwater and return to the sea to spawn and die. American eels are among the longest-lived fish species in North America. A female American eel held in captivity was recorded to be 88 years old prior to her death. The females are larger than the males, averaging three feet long while the males generally reach 1.5 feet long. The females, which have not yet reproduced, are generally what are caught in freshwater systems. The largest eel taken in New York State was seven pounds and 14 ounces, from Cayuga Lake in 1984. At maturity a female can lay between 10-20 million eggs.

The migratory nature of eels means that they can travel thousands of miles upstream, lakes, up and around waterfalls and small dams. They can even travel overland during rainy nights, creating the myth that they come out of the water and crawl across the land. Larval eels that are located out at sea are called leptocephali, they are transparent, ribbon-shaped and are poor swimmers. At age one, the leptocephali swim to shore along the coast of the United States and transform into elvers or glass eels. During this process, they gain their coloring and shrink in size. At this time females will migrate great distances upstream to mature, while males will stay closer to the coast.

After 20-50 years in freshwater the eels transform again into silver eels and move back out to the spawning area, the Sargasso Sea in the Atlantic Ocean to spawn and then die. The mating behavior of the American eel has never been witnessed. The diet of eels varies by size; the smaller eels eat insects such as mayflies and caddisflies, the larger eels will eat fish and crustaceans, They are most active at night, spending their days hiding under rocks and in the mud.

Eels are considered commercially important in New York and are frequently caught by anglers. American Eels were historically caught for their skins, which were used to bind books or for their oils which were used for medicinal purposes. Today Eels may contain high levels of PCB’s and cannot be commercially sold. Throughout New York State, except the Hudson River, St. Lawrence River, Niagara River, Lake Ontario, and tributaries to these waters, you can fish for American Eel all year. The minimum length is 6 inches with a daily limit of 50.

Corrina Parnapy is a Lake George native and a naturalist who writes about the environment and Adirondack natural history for the Adirondack Almanack.

Photo: An American Eel caught by US Fish and Wildlife Service Biologist Steven Smith holding an eel caught while night electrofishing for salmon in Whallon Bay, Lake Champlain. Photo courtesy USFWS.

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Corrina Parnapy, an Adirondack native  transplanted to Vermont with her husband and son, is the District Manager for the largest Natural Resources Conservation District in the State of Vermont.  She is the lead Aquatic Biologist/ Phycologist for Avacal Biological, and writes about the natural world for the Adirondack Almanack and other Northeast publications.

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