Seattle Salmon Death: Scientists Develop Potential Solution by Preventing Up to 96% of Tire Particles from Escaping [Study]

Salmon deaths due to tire pollution have long been a problem in Puget Sound, a complex estuarine system located on the northwestern coast of Washington state. The pollution affects the coho salmon species in the streams of the sound, which consists of interconnected marine waterways and basins. This ecological, and environmental issue is evident in the city of Seattle, based on reports since 2020.

The pollution involves not only the spread of tire particles but also the leakage of toxic chemicals from the industrial rubber material. These hazardous particles lead to large numbers of salmon deaths at Puget Sound every year, particularly coho salmon (Oncorhynchus kisutch) in urban streams. The fish species is native to the northwest part of North America.

To address the freshwater ecological disaster, scientists revealed in their new study published earlier this month of developing a potential solution against Seattle's salmon deaths. This is possible by mitigating tire wear particles and tire-related chemicals in stormwater using permeable pavements, according to researchers based in the state of Washington, United States.

Seattle Salmon Death

In the study published in the journal Science of the Total Environment on January 15, researchers from Washington State University examined permeable pavements due to their ability to treat tire particles and leachable tire chemicals. These pavements have been proven to significantly reduce or prevent Seattle's salmon deaths.

The solution, which involves four different types of permeable pavements, prevents up to 96% of tire particles from escaping. The new research paper highlights these pavements serve as filters for tire pollution. This is not the first time that these structures have been considered for varying real-world applications due to their evident benefits.

According to the U.S. Geological Survey (USGS), a permeable pavement is a "porous urban surface" which filters precipitation and surface runoff. It then stores what it catches in the reservoir while gradually allowing it to infiltrate into the soil below. The USGS in 2019 also cited a study that showed that different types of permeable pavement reduce the number of pollutants and runoff volume.

Tire Pollution

Washington state's Department of Ecology on January 25 mentioned the dilemma of scientists in solving the toxic mystery of the deaths of coho salmon returning to urban streams and rivers in the Puget Sound region. The journey of these fish is supposed to end up with them laying their eggs. However, a previously unknown culprit has been linked to toxic chemicals coming from roads and highways.

The tire pollution involving toxic tire dust contains a chemical called 6PPD-quinone, which is believed to be a deadly compound for the coho salmon, according to the Washington environment agency. It was reported that the toxic chemical is released from automotive tires that ends up in roadway dust and can result in running off into streams.