ANTHROPOGENIC EFFECTS ON LACUSTRINE FIDELITY: A STUDY OF LIVE-DEAD MACROINVERTEBRATE ASSEMBLAGES IN CONESUS LAKE, LAKEVILLE NY

Modern ecosystems are impacted by anthropogenic activities such as agriculture, tourism, climate and industry. Many lacustrine ecosystems are adversely affected, including shifts in community dominance, invasion of foreign fauna, and introduction and regulation of sediment and nutrients. These effects produce a current living assemblage that is less diverse and successful than death assemblages that precede it. Macroinvertebrates, sensitive to environmental perturbations respond quickly (decades or less) to changes in water quality, sedimentation and ecologic shifts, making them suitable for lake community assessment.To determine the fidelity of a heavily impacted lake, this study focuses on the live-dead and pre-fossil macroinvertebrate assemblages of Conesus Lake, a Finger Lake located in Lakeville, NY.

Our hypothesis is that the preserved skeletal community is more abundant and diverse than what is alive today. Two different locations of Conesus Lake were selected, the North and the South ends. The North is a park and sandy beach largely anthropogenically controlled, while the South is a marsh containing a popular fishing inlet. To compare the live-dead and pre-fossil community, data was collected in three phases. Phase 1: Sampling of lake water along multiple sampling sites tens of meters across, where additional samples were also collected. Chemical properties (temperature, pH, total dissolved solids, dissolved oxygen) were determined from each sample. Phase 2: Surface sample collection at each site, followed by wet sieving, live-dead collection and counts, and grain size analysis. Phase 3: Coring several centimeters (~20-40 cm) of lake sediment, followed by dry sieving, pre-fossil collection and counts, and grain size analysis.

The final aspect of this study includes quantitative analysis of the live, dead and pre-fossil assemblages focusing on changes in diversity and dominance over time. Elemental concentrations in the shells will be estimated using Inductively Coupled Plasma Mass Spectrometry. These analyses could reveal an increased anthropogenic influence on the lake over the last few decades, negatively impacting the living organisms present in the lake today. The outcomes of this study will help support the conservation of Conesus Lake, in addition to the other Finger Lakes in New York.