Bryozoans—Possible Indicators of Environmental Quality in Bear Creek, Mississippi
1984
Cooper, Charles M. | Burris, John W.
Collections of samples of water and substrate materials from lakes and stream sections of Bear Creek, Miss., were studied to determine the species of Bryozoa present in different habitats of an aquatic ecosystem with an intensively cultivated flatland watershed (440 km²). Bear Creek (83 km long), a tributary of the Yazoo River in the Mississippi River alluvial delta, is actually a series of six riverine lakes connected by a sluggishly flowing stream. The watershed also includes several other oxbow lakes connected to the stream only during periods of high discharge. Water quality as characterized by total and suspended sediments, deposited sediments, pH, and coliforms deteriorated in a downstream direction. Four species of the sessile colonial invertebrate were indigenous to the three lakes in the system having the lowest total solids, sedimentation rates, and pH. These included Plumatella fruticosa (Allman), Lophopus crystallinus (Pallas), Fredericella sultana (Blumenbach), and Pectinatella magnifica (Leidy). Absence of bryozoans, especially environmentally sensitive Pectinatella magnifica, in downstream areas correlated with degradation of downstream habitat and increased total solids. Selective habitation of these invertebrates in the Bear Creek stream system indicates the possible use of these organisms as environmental indicators of habitat quality.
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