Research highlights | Jun 3, 2022 | By Kerri L Ackerly, Postdoctoral Fellow, Lecturer Department of Marine Science, University of Texas at Austin, College of Natural Sciences , Sumeep Bath, Editorial and Communications Manager
This Is What Tires Can Do to Freshwater Fish … and What We Need to Do About It
Life Is a Highway…
Here in North America, it is no secret that we love our cars.
In fact, in 2021, there were 289.5 million registered vehicles in the United States alone—almost one for every person.
And while we are always balancing the benefits and conveniences that automobiles afford us with the potential impacts on the environment, it seems as though there was one effect—from a chemical we didn’t even know existed—of which we had not even been unaware.
Here Comes the Science…
Just a couple of years ago researchers at the Center for Urban Waters (affiliated with University of Washington-Tacoma) discovered 6PPD-quinone.
To cut a long story short, rubber tires used on cars are strengthened to withstand the road and the elements. Imagine a preservative that lengthens the shelf life of a food product in the grocery store, but for tires.
This preservation process includes using a protectant called N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine—or 6PPD as it is known to its friends. Over the years, as the surface of the tire breaks down, those particles are exposed to the sun and to oxygen in the air and form a newly discovered chemical called 6PPD-quinone.
While we are always balancing the benefits and conveniences that automobiles afford us with the potential impacts on the environment, it seems as though there was one effect—from a chemical we didn’t even know existed—of which we had not even been unaware. Until recently.
It turns out that when this chemical gets washed away from roads—during storms, for example—into surrounding water bodies, it can have some pretty deadly consequences for the wildlife that resides within.
A Fish Out of Water…
For a while, researchers had been pondering why stormwater runoff caused the deaths of swathes of coho salmon across the western coast of the United States. Recently, they were able to make the link to 6PPD-quinone.
This matters for many reasons. Coho salmon are popular among recreational fishers, but they are also an environmentally important species within lake ecosystems, so a change in their populations can have knock-on effects on the whole food web. It now also seems that 6PPD-quinone could be deadly for rainbow and brook trout—although interestingly not for Arctic char or white sturgeon, nor for zebrafish and Japanese medaka, as recent studies have shown.
So … Now What?
This is where IISD Experimental Lakes Area (IISD-ELA) comes in. A series of 58 lakes and their watersheds in northwestern Ontario, Canada, IISD-ELA is the only place in the world where scientists can perform research on and manipulate real lakes to build a more accurate and complete picture of what human activity is doing to freshwater lakes.
The findings from over 50 years of ground-breaking research have rewritten environmental policy around the world—from mitigating algal blooms to reducing how much mercury gets into our waterways—and aim to keep freshwater clean around the world for generations to come.
This summer, researchers from the Nielsen Lab at the University of Texas are making the most of IISD-ELA’s whole-ecosystem approach to freshwater research.
They will be heading up to the site and constructing some small mesocosms in one of our lakes into which they will add some 6PPD-quinone to simulate a storm event.
They will then spend the summer monitoring many aspects of the water column—from the water chemistry to the fish and insect populations—to investigate the impact that 6PPD-quinone has on freshwater bodies at a way broader scale than we already understand.
These types of studies are so important because they give us experimental data that help scientists and policy-makers come together to work out what the risk to the environment really is. Without these data about the levels of risk to organisms, we can’t recommend or implement effective policies and regulations to preserve these sensitive—and highly important—species, habitats, and ecosystems.