Pregnant Pocketbook Mussel

Study chamber containing a pregnant pocketbook mussel (Lampsilis cardium) exposed to an elevated water temperature of 32 degrees Celsius. This mussel is showing signs of stress--lying on top of the substrate and unable to burrow.

The freshwater mussels that provide pearls for jewelry and nutrients to aquatic ecosystems may be further threatened by rising water temperatures in the Upper Mississippi River.

Nearly 70 percent of the 300 species of freshwater mussels in North America are in jeopardy of extinction, a situation that may increase in the future as a result of climate change and other stresses on aquatic ecosystems.  New research suggests that high water temperatures may cause mortality of pregnant females in the Upper Mississippi River, according to the USGS and the University of Wisconsin–La Crosse.