Changes in Diatom Assemblages in Canoe Lake: Climate Change and Watershed Influences

Long-term sediment records from lakes provide a valuable historical perspective for comparing recent environmental changes with past conditions. This study reconstructs the environmental history of primary production and nutrient dynamics in Canoe Lake, located adjacent to the west side of Frontenac Provincial Park, Ontario. Although minimally impacted today, Canoe Lake was historically affected by settlement-related disturbances, including logging and damming. It is classified as oligotrophic, with low phosphorus levels (<10 µg/L), and supports a natural Lake Trout population. A paleolimnological approach was used to reconstruct past environmental conditions by dating the lake core and analyzing the diatom assemblages preserved in the lake sediments as proxies of changes in primary production and past levels of nutrients. Diatom species assemblages were identified and analyzed to determine whether shifts occurred over the past ~200 years and if these changes correlate with known watershed disturbances. I hypothesize that shifts in diatom assemblages will reflect changes in primary production due to both anthropogenic and natural forces. The findings will contribute to ongoing research efforts to understand how ongoing climate change has impacted primary production in aquatic ecosystems in the region, specifically in Trout lakes.