Populations of freshwater mussels have been devastated in Iowa and many other states in recent years by things like loss of habitat, mining, chemical contamination and invasive species.

The U.S. Fish and Wildlife Service recently listed two mussel species as endangered, the sheepnose and the spectacle-case.

In Iowa, they’re found only in the Mississippi River where populations have decreased drastically since the mid-1980s.

Tamara Smith of Bloomington is a wildlife biologist with the U.S. Fish and Wildlife Service and says mussels are an important part of the ecosystem.

“Mussel beds provide habitat for other aquatic invertebrates and also fish. They provide stream-bed stabilization,” Smith says. “Mussels are food items for other animals like raccoons, otters and wading birds. Most importantly, mussels filter water. They’re filter feeders so they’re constantly filtering water thereby benefiting water quality.”

Smith says many populations of freshwater mussels are isolated and small in Iowa and it will take human intervention to increase numbers.

Sheepnose mussels were originally found in the Des Moines and Mississippi Rivers. The last known Iowa River sheepnose was found in 1985.

Smith says listing the mussels as endangered will lead to a road of recovery.

“It raises awareness of their presence,” Smith says. “It focuses conservation planning and funding and provides additional opportunities for partners who are working on them to get more funding and participation.”

Since 1990, sheepnose mussels have left 51 U.S. rivers, including the Des Moines and Iowa rivers. During that same time, spectaclecase mussels left 24 U.S. rivers.