Danielle A. Greco
Alexandra McClymont

Salinity is increasing in freshwater lakes worldwide, driven by the overuse of road salt, unsustainable agricultural practices, mining operations, and climate change. Increasing salinity is detrimental to biodiversity and overall lake health and a new study suggests that current governmental guidelines are insufficient to protect freshwater organisms. Queen’s University Biology Dr. Shelley E. Arnott, along with graduate students Danielle A. Greco and Alexandra McClymont, and collaborators around the world recently published their findings which illustrate the need for governmental reassessment of current water quality guidelines.

This striking study leveraged the results from an extensive network of experiments conducted across North America and Europe involving freshwater lakes. A collective loss of zooplankton taxa, the pillars of lake food webs and ecosystems, occurred in response to increased salinity even at the lowest water quality guideline thresholds. This loss of zooplankton leads to cascading changes in other components of the food web, resulting in the loss of water clarity and potential declines in fish populations. Overall, this research underscores the need to re-evaluate water quality guidelines in freshwater lakes worldwide to protect lake ecosystems. Likewise, these results show the need for innovative solutions to road de-icing, sustainable agriculture, and mining operations. Read the paper in PNAS.