VIU researchers investigating origins of toxic tire chemical that can kill salmon


Vehicle traffic on our roads can lead to all sorts of toxins ending up in nearby rivers and streams and a study being done at Vancouver Island University is trying to learn more about a chemical released from tires.

The chemical is known as 6PPD-quinone, which is released from vehicle tires and is acutely toxic to salmon at extremely low levels.

“Very small particles of tire rubber that when the rain hits they dissolve these compounds out into the streams so in an urban environment this is really important where you have high traffic density,” said Erik Krogh, co-director of VIU’s Applied Environmental Research Laboratories (AERL).

The University of Washington first identified the problem in 2020 so now VIU is trying to determine the critical hot spots on Vancouver Island by testing 53 waterways in 99 locations between Victoria and Campbell River.

“Salmonids in urban streams have multiple challengers not the least of which is climate change and land use in general but on top of that these tire wear toxins,” added Krogh.

One of the graduate students on the projects says streams near higher traffic areas are seeing higher readings of the chemical.

“Victoria is a little more population dense, has a little more traffic so we can see some higher hits there but it was also very location dependent,” said graduate student Angelina Jaeger.

Over 100 volunteers coordinated by the BC Conservation Foundation have collected thousands of water samples over the last year.

“It’s roadway driven and really quite short-lived and so we knew the concentrations were going to be really dynamic over space and time meaning you need to measure a lot of samples to actually characterize where it is,” added graduate student Joseph Monaghan.

Krogh said VIU’s method is significantly faster and more cost-effective than conventional methods. It allows for much greater numbers of samples to be analyzed and the faster turnaround improves engagement with project partners. Ultimately, this project will enable better decisions about stormwater management and help protect salmon habitat on Vancouver Island and beyond.

“This project involves many volunteers who are willing to go out in the rain to collect samples,” said Krogh. “None of us could do this work in isolation. It’s a team effort.”

In the streams, there are a number of fish species that are affected.

“Coho are by far the most vulnerable species that have been tested at least from the papers that I’ve read so far,” said Haley Tomlin of the BC Conservation Foundation. “Some other local species that have been impacted are rainbow and chinook as well but at much higher concentrations than what we’re really seeing in any of the creeks around here.”

Once samples are collected they end up in a chemistry lab at VIU where the actual concentrations are measured.

The information is then shared with city planners and engineers who can plan diversions for roadway runoff such as gardens to act as a filter.

Dean StoltzDean Stoltz

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