For the Endangered American Eel, A Long, Slippery Road to Recovery

Ted Williams / June 24, 2016 /First Appeared on Yale e360

For the Endangered American Eel, A Long, Slippery Road to Recovery



The American eel isn’t just a U.S. native. It’s also indigenous to southern Greenland, Iceland, eastern Canada, inland to the Great Lakes, Central America, northern South America, and Caribbean islands. Despite this expansive range, the International Union for Conservation of Nature (IUCN) lists the species as “endangered.”

It would be in even worse shape without the Delaware River, which flows unimpeded 330 miles through New York, Pennsylvania, New Jersey, and Delaware. Few, if any, eel refuges are more important, and management on the Delaware provides a global blueprint for eel recovery.

American eels are “catadromous,” meaning they live in brackish and fresh water and spawn in salt. They thrive in the Delaware because there are no dams on the main river to block migration from and to the sea and because water quality is excellent.

Maintaining that water quality are the eels themselves and the role they play in sustaining the Eastern elliptio mussel. These mussels, which filter out silt and other pollutants, abound in the Delaware because they depend on eels for distribution, parasitizing them with “glochidia,” their larvae, which eventually detach. Some mussel species attract fish by waving appendages that resemble worms or minnows, then they blast them with glochidia. The eastern elliptio disperses glochidia in a mucus web that eels swim through.

More:
http://daily.jstor.org/endangered-american-eel-a-long-slippery-road-to-recovery/