Freshwater mussels are disappearing at an alarming rate throughout North America, where scientists consider over 70 percent of all mussel species to be imperiled. Nearly half of Missouri’s mussels are species of conservation concern. The Kansas City Zoo, in cooperation with the Missouri Department of Conservation, U. S. Fish and Wildlife Service and Missouri State University, participates in the Fresh Water Mussel Propagation and Reintroduction Program. This important conservation program has been ongoing since 2007. With the help of Zookeeper Tracy Divis, young mussel species that are of either endangered or threatened status are grown out to adulthood right here in the Kansas City Zoo’s lagoon. Once they are a suitable size, the mussels are returned to their native rivers. As of Jan 1, 2017 this project has reintroduced over 19,000 specimens over 4 states. In addition to the work with the endangered and threaten mussel species, this project also works with common non-threatened species of mussels. Because mussels are sensitive to various pollutants, long lived, and often remain in one place their entire lives, their presence is often a sign of a healthy river or stream. Mussels can also accumulate pollutants from the environment. Scientifically analyzing them can be used to help us understand what chemicals or pollutants are affecting mussels and, more importantly, what water-quality standards should be established to protect our rivers and the organisms that live in them for future generations of Missourians to use and enjoy.