Researchers investigate impact of road salt on salmon
A group of researchers, including staff from the Department of Fisheries and Oceans, UBC, SFU, BCIT and volunteers with local stream-keepers groups, is beginning a study to look into the impact of road salt on salmon in creeks around Metro Vancouver.
According to the group, there's already research showing that high concentrations of salt in freshwater — where salmon begin their lives — can be harmful, but it's not known exactly how much salt is winding up in streams around Metro Vancouver, and it hasn't been established that the effects on Pacific salmon are the same as those on Atlantic salmon that have already been studied.
"Some of the levels of salt which have been measured already in Vancouver-Lower Mainland creeks, we think, could easily damage, if not kill the fish," said Chris Wood, adjunct professor of zoology at the University of British Columbia and principal investigator on the five-year study.
Salmon are seen spawning in Stoney Creek in Burnaby, B.C. (Credit: UBC)
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According to Wood, Pacific salmon are in an alarmingly precipitous decline, which is believed to be the result of many different causes. But he says road salt making its way into the water could be one of the factors.
When road salt is washed off the streets by rain or melting snow, it goes into storm drains, which go untreated into waterways.
Volunteers carrying out the work
According to Wood, volunteers with 13 different local stream-keepers groups are expected to take on more than 7,000 hours of work for the study over the next five years.
One of those volunteers, Alan James, a member of the Stoney Creek Environment Committee, and his group have been looking into the issue for more than 15 years in Stoney Creek, which begins at the Simon Fraser University campus before draining into the Brunette River and then into the Fraser River.
On Saturday, James and his fellow volunteers counted as many as 400 chum and 30 coho salmon in Stoney Creek during a spawning survey. For the new study, they'll do regular water conductivity measurements, which reveal the concentration of salt, as well as invertebrate counts, to determine how healthy the streams are and what sort of food the salmon are eating.
"It's very exciting for me. I'm really looking forward to it," said James, who said members of his group have been doing citizen science for several years, but they needed academics like Wood to repeat the research and get it peer-reviewed.
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Wood said that based on work carried out last year, they know that salt levels in Stoney Creek were seven times the provincial guideline for acute toxicity and 28 times the provincial guideline for chronic toxicity.
"We suspect that there could have been damage," he said.
"Salt input [in streams] is something we could potentially manage better. We're not saying that salt is all bad — salt is good in many ways. It makes our lives safer when we salt roads — but we do think there is a tendency to overuse salt and not apply it in the most thoughtful manner," said Wood, adding that if you can see the salt in clumps or even the crystals on the road or sidewalk, there's too much being used.
