PALEOLIMNOLOGICAL RECORDS OF HUMAN IMPACT ON BASS LAKE, OH

Bass Lake, Geauga County, Ohio was recently acquired by the Geauga Park District. As part of a preliminary assessment of the lake and its surrounding land-use pressures, we conducted a paleolimnological investigation of recent sediments. Using a hand-driven piston corer, we extracted a 92 cm core from Bass Lake. We oven dried 1 cm sub-samples at 110°C to determine water content and conducted loss-on-ignition analysis for each interval to determine organic carbon content. Based on carbon content fluctuations, we analyzed selected intervals for fossil diatom assemblages. Correspondence analysis was conducted to determine major changes in diatom assemblages and changes in diatom-inferred total phosphorous concentrations were calculated from existing nutrient optima data sets. Written historical records were collected to determine possible human impacts, and compared with LOI carbon and diatom data. Evidence of damming in the 1900s and eutrophication due to recent development is seen in the carbon and diatom record. Future work includes obtaining 210Pb dates, to further evaluate anthropogenic changes in Bass Lake and extracting the entire sediment record to investigate Holocene climate variation in Bass Lake and the surrounding Lake Erie watershed.