Investigating the effect of water hardness on the toxicity of Sodium Chloride (Salt), Potassium Chloride, and a road salt alternative to larval freshwater mussels

Investigating the effect of water hardness on the toxicity of Sodium Chloride (Salt), Potassium Chloride, and a road salt alternative to larval freshwater mussels is an open dataset from Environment and Climate Change Canada with 5 files (CSV, HTML); catalogue record updated 2026-10-13. On CanQuery you can open 3 CSV or Excel files as tables, filter, chart and export up to 10,000 rows as CSV and follow the original downloads. Files are available in English and French.

Freshwater mussels, one of the most imperiled groups globally, are particularly sensitive to salt, though it was unknown how they would respond to salt in the soft waters where zooplankton experience toxicity at chloride concentrations below water quality guidelines. We found that freshwater mussel larvae (glochidia) are significantly more sensitive to salt in soft water compared to exposures in waters with greater hardness. While an increase in water hardness reduced salt toxicity, protection typically plateaued in moderately hard water demonstrating a limit to the protection afforded by complex waters. This study is the first to examine the toxicity of salt to early life stage freshwater mussels in very soft, ion-dilute waters (< 30 mg CaCO₃/L) and we report that two species, including a Species at Risk, experienced acute toxicity at chloride concentrations below the long-term Canadian Council of Ministers of the Environment (CCME) Water Quality Guideline for the Protection of Aquatic life.

Publisher

Environment and Climate Change Canada

Resources

5

Catalogue metadata updated

2026-10-13