Effects of Water Diversion on Freshwater Mussels in the Pearl River Near WalkiahBluff, Mississippi and Louisiana, 1995

摘要

A survey to assess community characteristics, density, population demography ofdominant species, and the presence of endangered species of mussels (family: Unionidae) was conducted in the. Pearl River near Picayune, MS, August-October 1995. Work was done for the U.S. Army Engineer District, Vicksburg, and results are being used to assess the environmental effects of three proposed water diversion alternatives designed to increase discharge and water levels in the Pearl River near Walkiah Bluff, Mississippi and Louisiana An increase in water level in Reaches 1-4 of the Pearl River will be brought about by a decrease in discharge and water levels in Wilson Slough and areas downstream (Reaches 5-7). Low flow will be maintained in the river near Walkiah Bluff with a weir and closures in Reaches 1 and 2. Reaches 1 and 2 contain a rich and diverse assemblage of mussels. Recruitment is high, and where suitable substratum exists, high-density populations of mussels were found. Shells of the threatened inflated heelsplitter were found in Reaches 6 and 7, although no live specimens were collected. This species was not found in Reaches 1-4.