Research conducted by the University of British Columbia and partners has revealed that road salt used in the Lower Mainland during fall and winter may be posing a threat to juvenile salmon. The collaboration between UBC, Simon Fraser University, British Columbia Institute of Technology, and Fisheries and Oceans Canada examined 30 streams over three years. Findings indicate that while adult salmon manage to thrive in saltwater, young salmon suffer fatalities and deformities when exposed to high levels of road salt during their early development in freshwater.
The study employed approximately 40 water quality monitors across the region to identify spikes in salt contamination, recreating these conditions in the lab with salmon eggs and juveniles. The data showed that salt levels during certain periods could reach up to 10 times the acute water quality guidelines for freshwater streams, reducing survival rates of salmon eggs significantly.
Preliminary results revealed salt pulses eight times the guideline saw a 70% die-off in salmon eggs, with those surviving salt conditions at three times the guideline showcasing fatal deformities in about 4% of hatched fish. The research suggests the current level of road salting during November and December might be detrimental to coho and chum salmon species.
Going forward, researchers recommend using the minimum necessary amount of road salt for safety and suggest switching to brine, which is more efficient and environmentally friendly. This study highlights the potential impact of road salt on aquatic ecosystems and urges immediate action to mitigate risks to vulnerable salmon populations. Further investigations are planned to explore long-term non-lethal effects of salt exposure on salmon and collaborate with partners to observe its impact on juvenile coho salmon in the upcoming fall season.
