A diatom-based assessment of multiple stressors over the past ∼220 years on shallow Cranberry Lake in the Rideau Canal (Ontario, Canada)

A significant shift in diatom communities around 1980 marks the most pronounced ecological change in Cranberry Lake's history, linked to accelerated warming and prolonged ice-free periods. This study reconstructs the lake's environmental history using a sediment core, revealing transitions from marshland to lake formation (ca. 1800 CE) and subsequent ecosystem alterations due to canal construction (ca. 1830 CE). Diatom shifts since 2012, coinciding with nuisance algal blooms, suggest warming-driven limnological changes, despite stable nutrient levels. The research combines diatom analysis with historical records and modern monitoring data to uncover the impacts of multiple stressors—flooding, settlement, invasive species, and climate change—on this UNESCO-listed system.

Gallinger, M., Rühland, K. M., Graves, E. L., Paterson, A. M., & Smol, J. P. (2026). A diatom-based assessment of multiple stressors over the past ∼220 years on shallow Cranberry Lake in the Rideau Canal (Ontario, Canada). Botany, 104, 1–14. https://doi.org/10.1139/cjb-2025-0102