STREAM Project Studies Salmon-Killing Tire Toxin

STUDENT SCIENTIST
STREAM Project Studies
Salmon-Killing Tire Toxin
Protecting Metro Vancouver's urban salmon
from toxic tire runoff. BY SIMON DREW
NEW $1.8-MILLION research project called Salmonid Toxic
Runoff Exposure and Mitigation (STREAM) aims to identify
salmon streams and rivers affected by the newly discovered tire
toxin 6PPD-quinone (or 6PPDQ) and test new ways of protecting
salmon from 6PPDQ using newly designed green infrastructure.
The project is being led by UBC researchers in partnership with researchers
at Simon Fraser University and the Department for
Fisheries and Oceans (DFO), which is also providing
the funding.
For many years it has been known that something in
road runoff is killing salmon in the U.S. Pacific Northwest and B.C.’s south coast. After some rain events,
large numbers of dead salmon (especially coho salmon)
could be found in the water and along the banks of
nearby rivers and streams. Local salmon hatcheries reported incidents where nearly all their new releases were
found dead almost immediately after they had been
released. In 2021, research at the University of Washington discovered that the culprit is 6PPDQ. The toxin is
produced from the transformation of 6PPD, a chemical
added to car tires to prevent them from breaking down.
6PPDQ leaches out of tires and tire debris when it
rains, and then is delivered into nearby streams through
the urban drainage system.
“Road runoff poses a big risk to salmon, so we are
For many years it
looking to understand where the problem is worst in
the Metro Vancouver area and create new ways in which
has been known that
we can protect our salmon,” says Dr. Rachel Scholes,
something in road runoff
the lead researcher on the project in the Department of
Civil Engineering at UBC.
is killing salmon in the
The discovery of 6PPDQ immediately raised a number
of urgent research questions. Are all salmon species
U.S. Pacific Northwest
vulnerable? What about other fish and aquatic animals?
and B.C.’s south coast.
Is this toxic effect seen in other parts of the world? These
A
Simon Drew
The author is an
environmental scientist
who has worked on nutrient
pollution in coastal waters
of Europe and Australia as
well as carbon management
of peatlands in Scotland,
England and Asia. He is the
Research Manager of the
STREAM project.
28
WATER C AN ADA • M ARCH/APRIL 2024

Paperturn flipbook