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How Are Car Tires Driving Up the Price of Salmon?


How Are Car Tires Driving Up the Price of Salmon?

By Noah Whitfield

The Smithsonian National Museum of the American Indian states that the native tribes of the Pacific Northwest “define themselves as Salmon People”, a name that unifies all the diverse people of the area. 

Celio Falls in Oregon, known by local tribes as Wy-am, was a communal salmon fishing spot known by native people for thousands of years. Marketplaces and even entire villages were built near these white water cascades, making it one of the continent’s oldest settlements.

In 1957, Wy-am was flooded due to government interference and the local tribes lost a cultural landmark. The tragic event lives on in the collective memories of northwestern tribes and goes to show that salmon is more than a diet food. For many, it has been and continues to be a way of life.

Nowadays, salmon has become the fish of choice for people all over the world, not just Native Americans. And who doesn’t like a spicy salmon roll, after all?

Since 1980, salmon is three times more widely consumed worldwide and appetites for the fish aren’t going away any time soon. Too bad the same cannot be said about the fish themselves.

In 2019, the commercial fishing industry caught more than $30 million worth of Coho Salmon, or roughly 27 million pounds. Coho Salmon is fished responsibly under U.S regulations, making it a “smart seafood choice” according to NOAA Fisheries. 

Populations of Pacific salmon are slowly declining and shortages in the market will eventually drive prices up. 

Climate change and dam building are commonly known factors affecting the ecosystems where salmon live. What they didn’t explain was the wide-scale salmon deaths occurring when these beautiful fish returned to freshwater to lay their eggs.

Coho Salmon, like most species of salmon, are known to die after laying their eggs to make way for the new generation. But since the 1980s in the Pacific Northwest, an invisible killer has been wiping out huge numbers of salmon with their eggs still inside. The phenomenon has been coined “spawner mortality syndrome”.

At the time, no one knew what the invisible killer was, but it appears that the salmon death mystery has been solved.

A 2020 toxicology study by the University of Washington links unexplained Coho Salmon deaths in Seattle with tire rubber. 

Why is Tire Rubber Lethal to Coho Salmon?

In the study, Zhenyu Tian and his fellow scientists soaked pieces of tire rubber in water and what they found was mind-boggling.

The contaminated water was revealed to contain over 2,000 possibly harmful chemicals.

One of these chemicals is known as 6PPD,  a widely-used preservative that absorbs ground-level ozone, an air pollutant, and stops it from eating away at tire rubber. 

While 6PPD makes tires stronger and longer lasting, it is also the key ingredient to a harmful chemical cocktail.

6PPD and ozone create what is called 6PPD-quinone and it kills Coho Salmon in 4 tragic steps: lethargy, loss of orientation, disequilibrium, and then death.

Thousands die this way each year and will ultimately make salmon much less affordable to the everyday consumer. 

But, what is causing this problem? Are too many people dumping their used tires into the salmon’s habitat? No, not exactly.

Tires wear down over time, leaving tread on roads and particles in the air. When storms sweep through urban areas, the toxic residues left on roadways mix with stormwater. This combination forms the key ingredients in a harmful chemical concoction. To read more about tire pollution here.

During rainstorms, 6PPD is washed away and ends up in lowland creeks, contaminating the water and wreaking havoc on local ecosystems. 

The shocking results also explain why salmon in creeks nearest to the city were dying off on a larger scale.

How Big is the Impact of 6PPD?


NOAA Fisheries report that climate change and dam building are tied to the loss of salmon populations in the Pacific Northwest. But how much of an impact does 6PPD have? Answer: a huge impact.

When more than 50% of fully grown Coho Salmon are dying prematurely, current populations cannot be replaced. This is a matter of sustainability and conservation.

Salmon are anadromous, meaning they are born in freshwater and then migrate to the ocean after hatching, eventually returning to rivers and streams to lay their eggs. After the eggs are laid, these rivers become the final resting place for the salmon that have reached the end of their life cycle. When this new generation of Coho Salmon are born, they swim back down to the ocean and the life cycle repeats.

Salmon migrations happen around the same time as seasonal rainfall, meaning that when these fish return home to breed, their habitats are flooded with rainwater polluted with 6PPD-quinone. 

Experts predict that Coho Salmon populations near Seattle roadways will die off completely in 20 to 30 years.

This is bad news for the price of Pacific salmon nationwide since harvests are lower than ever.

In 2020, Alaska Journal of Commerce reported the lowest landing of Coho Salmon since the 1970s at slightly more than 2 million. As supplies of salmon dwindle, major fisheries raise prices to adjust for the shortage.

What is Being Done to Prevent River Pollution?

Luckily, we are not shooting in the dark when it comes to solving the problem of river pollution. 

Environmental scientists are constantly trying to find ways to preserve river ecosystems from harmful highway run-off and there is even a name given to these strategies: Green stormwater infrastructure (or simply GSI).

One of the most effective strategies happens to be the most simple – soil composting.

In a 2015 study, scientists filtered highway run-off with columns of bioretention soil (60% sand and 40% compost) and found that the filtered water caused no harm to juvenile Coho Salmon. 

Soil with higher organic content acts as a natural water purifier for rainwater and is the cheapest and most practical tool in reducing river pollution and saving Coho populations.

How Can You Help?


Currently, there aren’t laws in place to stop the use of 6PPD in tire rubber. And as long as we use cars and trucks to get from point A to point B, we’ll have to deal with the consequences of tire pollution.

The Osborne Reef is an artificial reef off the coast of Fort Lauderdale, Florida was a huge failure after hurricanes and storms displaced the tires that were placed in 1970. Over 2 million tires were sunk to create an artificial reef.  The government will not allow the tires to be removed however many companies trying to make money are making clams they are removing the tires. 

Regardless, we should do whatever we can to stop tire pollution from reaching salmon in their spawning phase.

The main ways we can help are river cleanups and soil restoration. 

Duwamish River Superfund cleanup

Coho salmon are endemic to the Puget Sound area and for those living in  or near Seattle, there are regular community cleanups to participate in.

South Seattle’s Duwamish River Cleanup Coalition works to clean up the main waterways in the Duwamish valley, of which some are the most heavily polluted in the country. Watch this video to learn more.

These heavily polluted rivers are classified by the United States Environmental Protection Agency as “superfund sites”. This refers to the federal Superfund law that requires toxic waste sites to be cleaned up.

A large part of the coalition’s mission is to empower the Native people of the Pacific territories. Historically, Coho Salmon was the main food source for Western Native American tribes and a sacred animal in their cultures. Even today, Native Americans still fish to supply themselves with food and income.  

By participating in Duwamish community cleanups, you would be doing  your part in taking care of culturally-significant rivers and the salmon that live there.

Ocean Blue Project’s River Restoration Projects Program


Blue Ocean Project launched the Blue Streams & River Restoration Program, now called River Restoration Projects Program in 2012. The goal is to rebuild local ecosystems from the ground up.

Ocean Blue collaborates with the students from the University of Oregon to introduce fungi and microorganisms to the soil at Sequoia Creek in Corvallis, Oregon. Today we are working on the Oregon Coast at the Nehalem bay planting trees and removing nonnative plants for Salmon habitat. 

Not only does the project bring healthy nutrients to the soil, it also prevents nasty chemicals like 6PPD-quinone from poisoning nearby rivers after rainstorms.

Donate here to help fund more projects like this in the future.


Author bio: Noah Whitfield is an Indianapolis-based copywriter. He is also a world traveler, musician, and nature lover.