MICROFOSSILS RECORD THE SUCCESS OF REMEDIATION IN THE WESTERN FINGER LAKES, NY

Conesus Lake, a mesoeutrophic lake located in the Finger Lakes region of New York, has experienced cultural eutrophication over the 19th and 20th centuries. In the early 21st century, remediation was implemented, to reduce the large amounts of nutrients introduced to the lake by various land-use practices in the surrounding watershed. Conesus Lake contains six species of ostracods, including Cypridopisis vidua, Candona candida, Ca. ohioensis, Ca. ellipitica, Darwinula stevensoni, and Limocythere verrucosa. This study aims to show the effectiveness of remediation efforts using the diversity and abundance of ostracodes found in Conesus Lake. Piston and Bolivia cores were collected from the south basin of Conesus Lake. The cores were sampled at 1.8 meters depth and contained 154 cm of sediment. 1cc sub-samples of sediment were collected at one-centimeter intervals from 3 cm to 154 cm. Calcareous subfossils separated from the sediments and sorted. Using a stereomicroscope, the subfossils were identified to the lowest possible taxonomic level. A total of 601 ostracodes (1202 valves) were separated, counted, and identified from 50 horizons in the core. Six species of ostracods were determined, of the six, Cy. vidua and Ca. candida were the most prevalent throughout the core. Cy. vidua gradually increased toward the core-tops (recent) whereas Ca. candida showed elevated abundance at the base of the core followed by lower abundances throughout the core until reaching peak abundance near the core-tops. D. stevonsoni and L. verrucosa were rare throughout the archived sediments. Abundances of Ca. ohioensis were relatively low throughout the core. Ca. elliptica displayed lower abundances near both core-bottom and core-top with peak abundance near mid-core. Based on previous analyses, we propose that Ca. candida and Cy. vidua may be indicators of mesotrophic conditions, while Ca. ohioensis and Ca. elliptica may indicate eutrophic conditions. The return of Ca. candida and Cy. vidua to high abundances near the core-top reveals the positive impact of remediation on the ecosystem. We suggest that the monitoring of live ostracodes can be used to indicate Finger Lake trophic state.