Of the 300 freshwater mussel species native to the United States, 35 are extinct and 70 are listed as threatened or endangered. Mike Davis / Minnesota Dept. of Natural Resources

Norman, Okla.–Biodiversity in freshwater systems is impacted as much or more by environmental change than tropical rain forests, according to University of Oklahoma Professor Caryn Vaughn, who serves as director of the Oklahoma Biological Survey. “When we think about species becoming extinct, we don’t necessarily think of the common species in freshwater systems, many of which are declining,” says Vaughn. “We need to be concerned about these declines, because these common species provide many goods and services for humans,” she states. “Factors underlying these declines include water pollution, habitat destruction and degradation, and environmental changes, such as overexploitation of water and aquatic organisms, all of which are linked to human activities. Freshwater biodiversity is also threatened by climate change which is predicted to alter species ranges and abundance.” Vaughn studies freshwater mussels, or clams, that live in Oklahoma’s rivers. North America contains the highest diversity of freshwater mussels in the world with over 300 species, but over 50 percent of these species are declining. Oklahoma contains 55 mussel species, mainly in rivers in the eastern portion of the state. …