Revisiting lakes within the Rideau Canal system (Ontario, Canada) to assess the impacts of multiple environmental stressors over the past ~25 years using diatom-based paleolimnology

Recent diatom-based paleolimnological analysis of five lakes within the Rideau Canal system (Ontario, Canada) reveals that environmental changes over the past ~25 years, marked by increases in small planktonic diatoms and declines in large-celled Aulacoseira taxa, are best explained by regional warming and declining wind speeds rather than nutrient enrichment. Despite significant historical disturbances such as deforestation and canal construction, the most ecologically notable shifts occurred during this recent period, coinciding with rising chlorophyll-a levels inferred from sediment cores collected in 2019-2020. These findings suggest that climate-driven changes are reshaping lake ecosystems, even in the absence of increased nutrient levels, and may contribute to the emergence of cyanobacterial blooms. The study builds on earlier paleolimnological work by reassessing diatom compositional trends over the past >200 years using visible range spectroscopy.

Balasubramaniam, K., Rühland, K. M., Paterson, A. M., & Smol, J. P. (2025). Revisiting lakes within the Rideau Canal system (Ontario, Canada) to assess the impacts of multiple environmental stressors over the past ~25 years using diatom-based paleolimnology. Journal of Limnology, 84. https://doi.org/10.4081/jlimnol.2025.2192