Streams across British Columbia are going to be closely monitored for salt levels as part of a new study to determine if salt negatively impacts Pacific salmon.
Researchers at Fisheries and Oceans Canada, UBC, SFU and BCIT — plus local volunteers with a stream-keepers group — are studying levels of salt in more than 20 streams over the next five years.
“When when we put salt on the roads or on our driveways or on sidewalks, to melt ice, it can leach into the water and end up in streams where it has the potential to impact salmon,” says Patricia Schulte, a professor in UBC's zoology department.
Early data already collected suggests high levels of salt is present.
“We already know that there are times in Stoney Creek in Burnaby, where the salt gets to levels that are seven times higher than what's called the acute toxicity limit,” says Schulte, adding that amount would harm salmon quickly.
"It's 28 times higher than the chronic toxicity levels that are sort of mandated by the government and that's the sort of thing where lower levels might harm salmon over a long period.”
For the research project, automated loggers have been placed into the streams. Data from the loggers can be accessed in real-time by the volunteers on their cellphones and captured over time.
“Then the graduate students on our team will be analyzing the data,” she says. “We'll be sharing all the data publicly on a website. We'll be able to go to a map and kind of click on a stream in your area.”
There is not a lot of research on Pacific salmon, the native salmon in B.C., but data suggests salt is impacting Atlantic salmon on the East Coast.
“We have a pretty good idea that salt can be harmful,” the professor tells Glacier Media. “The question is, is it reaching those kinds of harmful levels regularly here in B.C. or is it just occasional?”
Studying the salt levels over five years will give insight into the impact of exposing salmon to low levels for a long time compared to a short amount of time but with high pulses.
“Our research is going to try and figure that out,” she says.
Beet juice instead of salt?
Some communities in Canada have switched to using beets on their roadways and sidewalks as an alternative to salt, but it’s not clear yet if that would negatively impact salmon.
"That's actually a really interesting question,” says Schulte. “People are trying a bunch of different things and certainly, beet juice is probably the most widely used.”
Back in 2017, Castanet News reported that 500,000 litres of beet juice was sprayed on the Coquihalla Highway to keep ice at bay.
Beets can reduce the amount of salt that's used, but has an ecological impact as well.
“Some of the sugars in the beet juice, what happens is the little microbes in the water eat the sugar and grow quickly, and then they use up oxygen, and that's oxygen that the fish need,” explains Schulte.
The B.C. researcher notes the salt-monitoring project will provide local governments and municipalities with valuable data.
“By working with the stream keepers, we'll be able to really get a sense of what's actually happening in our in our local streams,” she says.