Eels found off the coasts of the U.S. are often called glass eels because of their translucent skin. They come from the Sargasso Sea, a weedy breeding ground in the middle of the Atlantic. From there, the little eels swim to the coasts of the Americas and Europe, where they play crucial roles in marine ecosystems.
“Once eels return to the coast, they stock estuaries with food and become a predator of fish in freshwater streams,” Kilduff said. “While swimming upstream, mussel larvae hitchhike on eels, which means eels deserve some credit for the filter-feeding role of mussels.”