ASSESSING THE POTENTIAL OF THECAMOEBIANS AS WATER QUALITY INDICATORS IN WETLANDS ESTONOA, VIRGINIA

Since the early 1900s the Wetlands Estonoa area, previously called Lake Estonoa, in the southwestern Virginia town of St. Paul has existed as a wet cornfield, a swimming hole, an illegal trash dump, and, most recently, a reclaimed wetland. Students from the Appalachian ecology and physics classes at St. Paul High School worked with the Corp. of Engineers to have Estonoa certified as a wetland in 2000. Now as Team Estonoa the students continue to work to conserve and protect the area through participation in an innovative service-learning program. Due to its varied history Wetlands Estonoa is the perfect place to assess the potential of a new method for determining water quality. Testate amoebae known as thecamoebians are microscopic invertebrates with a mineralized shell that can be preserved in the fossil record. They are common in areas of muddy, slow-moving, fresh water. Due to their prevalence in many lakes, marshes, and wetlands and their sensitivity to variations in environmental conditions they have been used to determine land-use changes and water quality in Canadian and European lakes. Sediment and core samples have been collected from Wetlands Estonoa. Sediment samples will provide information on current thecamoebian populations and these will be compared with populations from dated core samples to see if changes in the community structure can be matched with the known history of the wetland. Additionally thecamoebian assemblages in sediment and cores from Wetlands Estonoa will be compared with populations found in sediment and cores from Oxbow Lake, also located in St. Paul. This is an artifical lake created when the Clinch River was re-routed after massive flooding of the town in the early 1980s. Preliminary results have identified Centropyxis aculeata from Wetlands Estonoa samples. This species is considered an opportunistic generalist and has been observed as a pioneer form appearing in periglacial lakes immediately after deglaciation.