AN INVESTIGATION OF DIATOM MORPHOMETRY AND POPULATION IN THE SEDIMENTARY ARCHIVE OF CONESUS LAKE IN WESTERN NEW YORK

Understanding anthropogenic impacts on lacustrine environments has become increasingly important due to the scale of human influence on lake ecosystem health. This project is part of ongoing research focused on Conesus Lake in Livingston County, western New York. Conesus is a mesotrophic lake currently undergoing remediation in response to water quality issues, decades of introduced and invasive species, and recent appearances of cyano-algal blooms. The purpose of this research is to investigate the ecosystem health of Conesus Lake by characterizing diatom populations in sediment cores. These cores capture pre-European colonization, pre-Industrial practices, and pre-Remediation signals archived in the sediment. If remediation efforts have been effective then we should see a shift in recent diatom populations from genera associated with eutrophic conditions toward those associated with mesotrophic. Diatoms have previously aided in analysis of lake health and climate based on genus distributions and sizes. For example, small-sized planktonic diatoms indicate gradual lake warming. Piston and bolivia cores were collected from the south basin of Conesus Lake and diatoms were extracted from the cored sediments for study. The cores provided excellent preservation of benthic and planktonic diatoms allowing for morphometric measurements and genus level identification of diatom communities using Scanning Electron Microscopy. Bivariate analysis of width:length ratio compared to depth will be applied to describe significant changes in diatom populations, evaluated by morphology and frustule size. Diatom size for certain species is useful for determining trophic conditions along with environmental changes. These diatom populations will be used to better characterize the environment and lake ecosystem over the past 300 years.