The U.S. Fish and Wildlife Service has listed the sheepnose and the spectaclecase, two freshwater mussels found in river systems in the eastern half of the United States, as endangered under the Endangered Species Act.
Sheepnose are currently found in Alabama, Illinois, Indiana, Iowa, Kentucky, Minnesota, Mississippi, Missouri, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin. The sheepnose occurs in 25 streams, down from 76, a 67 percent decline. Very few of these populations are known to be reproducing.
The spectaclecase once occurred in at least 44 streams but now occurs in 20 streams, a 55 percent reduction in the number of occupied streams. Of the 20 remaining populations, six are represented by only one or two known specimens each. Spectaclecase mussels are currently found in Alabama, Arkansas, Illinois, Iowa, Kentucky, Minnesota, Missouri, Tennessee, Virginia, West Virginia, and Wisconsin.
In listing the two mussels, the Service evaluated factors related to the species that could lead to extinction. Threats to both the sheepnose and the spectaclecase include loss and degradation of stream and river habitat due to impoundments, channelization, chemical contaminants, mining and sedimentation. Freshwater mussels require clean water; their decline often signals a decline in the water quality of the streams and rivers they inhabit.
The Service's final rule appeared in the March 13, 2012, Federal Register. The Service will now develop a recovery plan for the two species and work cooperatively with partners to conserve their habitats.
It is illegal under the ESA to kill, harm or otherwise "take" a listed species, or to posses, import, export or conduct interstate or international commerce without authorization from the Service. The ESA also requires all federal agencies to ensure actions they authorize, fund, or undertake do not jeopardize the existence of listed species.
SHEEPNOSE AND SPECTACLECASE IN IOWA
Sheepnose and spectaclecase mussels were originally in most of Iowa's large rivers but are now only found in the Mississippi River, mainly Pools 15 to 19. On a rare occasion they are found in upstream pools.
Iowa Department of Natural Resources fisheries biologist Scott Gritters has led mussel surveys and studies in Iowa rivers for 13 years and said they have not found many of either mussel.
"We have encountered live specimens of sheepnose and spectaclecase in our surveys, but very few," Gritters said. "We know little about their ecology, but for the species to survive, it will be critical to protect their remaining habitat."
More information on mussels and endangered wildlife can be found at www.fws.gov/midwest/endangered