Conservation and Management of Freshwater Mussels (Bivalvia: Unionoidea) in Missouri

Of the 69 species of freshwater mussels native to Missouri, 29 are Species of Conservation Concern (SOCC), including 11 federally listed or proposed as endangered or threatened.  The greatest abundance and diversity of mussels in the state is associated with the rivers draining the Ozark Plateaus, a distinctive highland biogeographic region with many endemic aquatic species, including the northward-flowing Meramec, Gasconade, and Osage, the southward-flowing White, Black and St. Francis, and the west-flowing Spring river systems.  A few of these rivers have so far escaped major impoundments, while the faunas of others dammed as recently as the early 1970s may not yet have reached equilibrium.  Other important regional impacts include gravel mining, heavy metal pollution from historic lead and zinc mining, nutrient pollution, and ongoing range expansion of zebra mussel. There are a number of conservation initiatives underway in Missouri, including faunal surveys to document species distributions, research into artificial propagation and restoration, population genetics research, ecotoxicological research to document the effects of contaminants on the various life stages of freshwater mussels and provide for more stringent water quality criteria, and working with private landowners to protect mussel habitats. Current research and management efforts in Missouri will be highlighted.