Leanne Elchyshyn

McGill University
M.Sc. candidate

Supervisor: Irene Gregory-Eaves
Start: 2013-09-03
End: 2016-10-31


Quantifying the effects of water-level drawdown on lake water quality and cyanobacteria abundances using paleolimnological techniques: A case study of Grand Lac Saint François, QC
Grand Lac Saint François is a large lake in southeastern Quebec currently experiencing a number of anthropogenic pressures. One evident stressor is the large seasonal water level drawdown due to the activity of a dam constructed over 100 years ago. The dam’s operations may be a potential source of the present concern of increased cyanobacteria abundance and changing lake trophic status. As no ‘pre-impact’ data on the lake’s conditions exists; the goal of this project is to reconstruct an ecological archive of nutrient concentrations and cyanobacteria abundances for the past 200 years using various paleolimnological techniques to see if construction of the dam has altered the trophic trajectory of this lake. Furthermore, we will look at these results in a regional context by comparing findings to similar studies within the region and the existing literature to note if general conclusions about water level drawdown and trophic conditions are realized. Findings will contribute to the development of better management plans by local organizations for not only Grand Lac Saint François but potentially all temperate lakes experiencing similar water level drawdown.