DETECTING ANTHROPOGENIC IMPACTS ON LIVE-DEAD MACROINVERTEBRATE COMMUNITIES IN HONEOYE AND CONESUS LAKES, NEW YORK

Anthropogenic activities such as agriculture, industry, and tourism influence modern environments. In particular, lacustrine ecosystems are sensitive to large-scale perturbations and are susceptible to human impacts that can leave a record of environmental change within sedimentary archives. Here we assess the anthropogenic impact in two New York Finger Lakes: Honeoye and Conesus, by comparing the time-averaged macroinvertebrate death assemblages to the living macroinvertebrate community. Both lakes are heavily influenced by human activity and show variable levels of productivity. We predict that the outlet region of both lakes represent a more impacted community based on the diversity, evenness and abundance of live-dead macroinvertebrate communities.

Surface sediments and water samples were collected near the lake’s inlets and outlets. Surface samples and water quality measurements were collected along a 40 meter transect at ten-meter increments from shore. From the surface sediments, live macroinvertebrates (soft-bodied and hard-bodied) were identified to the species level and counted. Sediment samples were subsequently dried and sieved to separate whole and fragmented skeletal remains of macroinvertebrates. Dead (hard-bodied) macroinvertebrates were counted and identified to the species level. Due to preservational biases, only hard-bodied organisms were used for analysis of live-dead agreement.

The inlets of both lakes contained greater abundance and diversity of live and dead macroinvertebrates. 36 species were found within the communities of Conesus Lake with a sample size of 1457 specimens. 2374 specimens representing 37 species were sampled from Honeoye Lake. 58% of the species sampled in both lakes are soft-bodied while gastropods and bivalves represent the hard-bodied species. Both lakes had similar species compositions, a few were unique to each location. Some species were especially dominant, including chironomids and zebra mussels both representatives of an impacted ecosystem. Overall, there was greater species diversity from the sample locations at the southern inlet of each lake compared to the less diverse and less even northern outlet communities.