The article discusses the acute toxicity of 6PPD-Quinone (6PPD-Q), a contaminant from urban stormwater runoff primarily attributed to tire rubber, on coho salmon in the Longfellow Creek watershed of Seattle, Washington. Urban stormwater can carry various contaminants into streams, affecting aquatic life, including the documented trend of Urban Runoff Mortality Syndrome (URMS) in coho salmon. The authors utilized the US EPA’s Visualizing Ecosystem Land Management Assessments (VELMA) ecohydrology model to map 6PPD-Q’s fate and transport to identify hotspots within the watershed.
The model’s enhancements allow for high-resolution simulation of hydrology, capturing how environmental conditions influence contaminant dynamics. Findings indicated a strong correlation between modeled and observed 6PPD-Q concentrations at stream locations. Despite some limitations related to the data and parameter uncertainties, VELMA proved effective for visualizing contaminant movement and could inform the implementation of Green Stormwater Infrastructure (GSI) to mitigate future toxic runoff impacts. The work underscores the need for comprehensive strategies to manage urban pollutants affecting sensitive aquatic species in urban environments.
Overall, the study emphasizes the potential of process-based modeling as a tool for developing urban water management practices to protect local ecosystems, especially for vulnerable species like coho salmon.
