US Geological Survey


Date of this Version



Freshwater Crayfish 16:97–111, 2008


Mining has occurred in the New Lead Belt of southeast Missouri, one of the largest producers of lead ore in the world, since the 1960s. We studied populations of the crayfish Orconectes hylas at 13 sites to assess the ecological effects of mining-derived metals in the Black River watershed, which drains much of the New Lead Belt. Crayfish density, physical habitat, and water quality were examined at one reference site with no known upstream mining activities and at sites downstream of mining areas. Metals (Pb, Zn, Cd, Ni, Co) were analyzed in sediment pore water and whole crayfish. Mean crayfish densities were significantly greater (P < 0.05) at the reference site compared to mining and downstream sites. Crayfish densities were negatively correlated (P < 0.05) with sediment pore-water metal concentrations, Cd concentrations in whole crayfish, and temperature, but not with any measured physical habitat variable. These findings indicate that metals associated with current mining activities in the New Lead Belt have negative impacts on crayfish populations in Ozark streams.