Hows The Water

3.21.12 Endangered Mussels

Harbors and bays are not the only bodies of water that benefit from the filtering actions of shellfish.  Two species of mussels have been placed on the federal Endangered Species List.  Despite their silly names – sheepnose and spectaclecase mussels – they fulfill the vital role in the ecosystem of filtering water, and helping to preserve water quality in our nation’s rivers.

The sheepnose and spectaclecase mussels will be protected following an agreement reached last summer between the U.S. Fish and Wildlife Service and the Washington, D.C.-based Center for Biological Diversity. Under that legal settlement, Fish and Wildlife agreed to expedite listing decisions on 757 imperiled species by 2017.

The spectaclecase has been eliminated from 20 of the 44 streams where it historically lived. Those habitats include parts of the upper Mississippi, Ohio, Cumberland and Tennessee rivers.  The sheepnose has been eliminated from 25 of the 77 waterways where it historically lived. Its former habitat included thousands of miles of the Mississippi, Wisconsin, Illinois, Ohio, Cumberland, and Tennessee rivers.

Freshwater mussels, which eat by filtering small particles from the water, are considered key indicator species. Because they need clean water to survive, their health reflects the health of the waterway.  Many of the nation’s shellfish, amphibians and reptiles are experiencing declines in their populations, and are disappearing from where they historically lived.  This is an ominous sign for the environment.

The sheepnose, once commercially harvested for jewelry and buttons, is oval and 5 inches long. It’s now found in Alabama, Illinois, Indiana, Iowa, Kentucky, Minnesota, Mississippi, Missouri, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and Wisconsin.

The spectaclecase is about 7 inches long and is found now in Alabama, Arkansas, Illinois, Iowa, Kentucky, Minnesota, Missouri, Tennessee, Virginia, West Virginia and Wisconsin.

Both species are threatened by pollution, dams and mining, but protection through the Endangered Species List has a 99 percent success rate.

More than 50 mollusk species in the eastern U.S. have already become extinct.