Using High-Resolution Mass Spectrometry to Identify Organic Contaminants Linked to Urban Stormwater Mortality Syndrome in Coho Salmon

Abstract

Urban stormwater is a major threat to ecological health, causing a range of adverse, mostly sublethal effects. In western North America, urban runoff is acutely lethal to adult coho salmon ( Oncorhynchus kisutch) that spawn each fall in freshwater creeks. Although the mortality syndrome is correlated to urbanization and attributed to road runoff contaminant(s), the causal agent(s) remain unknown. We applied high-resolution mass spectrometry to isolate a coho mortality chemical signature: a list of nontarget and identified features that co-occurred in waters lethal to coho spawners (road runoff from controlled exposures and urban receiving waters from two field observations of symptomatic coho). Hierarchical cluster analysis indicated that tire wear particle (TWP) leachates were most chemically similar to the waters with observed toxicity, relative to other vehicle-derived sources. Prominent road runoff contaminants in the signature included two groups of nitrogen-containing compounds derived from TWP, polyethylene glycols, octylphenol ethoxylates, and polypropylene glycols. A (methoxymethyl)melamine compound family, previously unreported in North America, was detected in road runoff and urban creeks at concentrations up to ∼9 and ∼0.3 μg/L, respectively. The results indicate TWPs are an under-appreciated contaminant source in urban watersheds and should be prioritized for fate and toxicity assessment.

Hyporheic Process Restoration: Design and Performance of an Engineered Streambed

“…Other researchers studying the water chemistry and biology have shown that this hyporheic restoration has also been effective at significantly reducing concentrations of incoming pollutants [29], and at enhancing both hyporheic microbial heterotrophic production and macroinvertebrate taxa diversity and richness [37]. Table A2.…”

“…Using mass spectroscopy, Peter et al [30] found significant reductions in the number and concentration of organic chemicals, some of which are potentially associated with coho mortality (as identified in [29]) both under both base flow and stormflow conditions through plunge-pool No. 4 at the Kingfisher site.…”

Hydrophilic trace organic contaminants in urban stormwater: occurrence, toxicological relevance, and the need to enhance green stormwater infrastructure

“…123,124 Exposure of healthy coho spawners to untreated highway runoff collected during storm events reproduced the mortality syndrome indicating that coho salmon are vulnerable to one or more chemicals present in runoff. 124,123 Using high-resolution mass spectrometry (HRMS), Peter et al 125 developed a chemical signature for the coho mortality by isolating HRMS features (i.e., exact mass-retention time pairs) that co-occurred in road runoff and field samples that caused symptomatic coho. This "coho mortality signature" was then compared to chemical signatures of several motorvehicle fluids and tire wear particle leachate.…”

“…This "coho mortality signature" was then compared to chemical signatures of several motorvehicle fluids and tire wear particle leachate. 125 The chemical signature of tire wear particle leachate displayed most similarity to waters that caused coho mortality. 125 Prominent chemicals identified in the coho mortality signature were octylphenol ethoxylates, glycols, bicyclic amines, and (methoxymethyl)melamine compounds.…”

Review of and Recommendations for Monitoring Contaminants and their Effects in the San Francisco Bay−Delta

“…Subsequent analyses that incorporated water samples from urban streams where spawning Coho Salmon consistently die prematurely in response to toxic stormwater (Scholz et al 2011) has narrowed the list of causal toxic agents to fewer than 100 chemicals (Peter et al 2018). Moreover, the HRMS approach revealed the presence of a family of (methoxymethyl) melamine compounds in urban waterways, the first such detections in North American surface waters (Peter et al 2018). These contaminants were subsequently linked to urban stormwater-related mortality syndrome in Coho Salmon, until then known to be the causing agent.…”