Stormwater Monitoring with Mussels

From Salish Sea Wiki

Wiki Rules

Link to List of Workgroups Link to List of Topics Link to List of Places

Link to List of Efforts Link to List of Products Link to List of Documents Link to List of Graphics Link to List of Websites

Link to Delta Sites Link to Embayment Sites Link to Beach Sites Link to Rocky Headland Sites

Link to Headwater Sites Link to Lowland Watershed Sites Link to Floodplain Sites

Stormwater runoff carries heavy metals and organic contaminants like oil and road grime unfiltered into Puget Sound. Since the timing and intensity of rainfall strongly affects the transport and dilution, the tradition method of grabbing and testing water samples does not reliably describe the amount of hazardous substances being released into the nearshore. Filter feeders like mussels continuously sample nearshore water, building a body burden of organic toxins and heavy metals. By testing mussel tissue, you can identify relative influx of hazardous substances in the nearshore water column at a point over time. Toxin concentrations over 73 sites across Puget Sound were shown to correlate with impervious surfaces in adjacent shoreline landscapes.


  • WDFW has been leading work in extensive monitoring using mussels, and organizes the Stormwater Action Monitoring program, which is a collaborative program funded by municipal stormwater permits.
  • Stormwater Action Monitoring (SAM) characterizes the extent of tissue contamination within Urban Growth Areas (UGAs).
  • File:Lanksbury et al 2017 mussel monitoring survey 2015-2016.pdf summarizes findings of extensive monitoring using mussels over the 2015-16 stormwater season. The most abundant hazardous substances observed where PAHs, PCBs PBDEs, and DDTs.
  • Mussels grown in UGAs had significantly higher concentrations of organic pollutants than those grown at Penn Cove.