2022 Salish Sea toxics monitoring synthesis: A selection of research

A 2023 report from the Puget Sound Ecosystem Monitoring Program presents an overview of selected recent monitoring and research activities focused on toxic contaminants in the Salish Sea. 

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The Puget Sound Ecosystem Monitoring Program (PSEMP) toxics workgroup aims to improve collaboration and information exchange among professionals working to understand the impacts of toxic contaminants in the Salish Sea. One way we achieve this is by compiling and publishing a synthesis report that includes brief updates on the monitoring, research, and management of toxic contaminants.

This is the third synthesis published, with those prior in 2016 and 2018. Together they provide a suite of snapshots of activities that document progress in our investigation, understanding, and management of anthropogenic chemicals.

Our main goal is to provide a summary of toxics-related monitoring and research in a single document to 1) communicate the range of efforts currently underway, 2) provide a brief summary of findings to managers and policy makers, and 3) form a basis to develop an inventory of research needs and monitoring gaps.

This 2022 version represents a compilation of activities of almost 50 groups in both the United States (U.S.) and Canada. We would like to note our appreciation to the contributors and applaud their dedication to their work.

Key messages

  • Some contaminants impact the health and safe consumption of fish and shellfish, particularly benthic species in urbanized areas, and pelagic fish from throughout Puget Sound. Persistent legacy contaminants, such as PCBs, are still widespread and cycle through the pelagic food web. PBDEs have been declining but are still affecting juvenile salmon in the Snohomish and Puyallup basins.
  • A number of regional monitoring groups are providing important exploratory and baseline data on legacy and emerging contaminants potentially impacting Orca and their main food source, Chinook salmon.
  • Although Puget Sound nearshore sediments are relatively clean, mussel tissue monitoring shows higher contamination in urban centers. Temporal trends of legacy contaminants in mussel tissues show an overall decrease in concentrations from 2017/18 to 2019/20.
  • Contaminants in roadway and stormwater runoff negatively affect the health of salmon and forage fish. More is being learned about the toxic effects and treatment of tire wear particles and 6PPD-quinone. For example, bioretention using soil-based media is a highly effective means of protecting biota from contaminant exposure and impacts.
  • Laboratory studies indicate that wastewater treatment plant effluent could cause adverse effects in fish where it enters the Salish Sea.
  • CECs, including pharmaceuticals and personal care products, have been detected in Salish Sea waters, and some like PFAS are being found widely in freshwater. Some of the CECs occur at levels high enough to harm fish and wildlife.
  • Pollution prevention efforts and cleanup, particularly those that include local community engagement and clear connections with human health, are effective strategies that can reduce contaminant exposures. Upstream strategies are also more cost effective and signal to manufacturers and processors to find alternatives.


This effort was organized through the Puget Sound Ecosystem Monitoring Program Toxics Workgroup with support from the Puget Sound Institute, University of Washington Tacoma, under the cooperative agreement PC-01J32201 from the US Environmental Protection Agency.

Suggested citation

PSEMP Toxics Work Group (2023). 2022 Salish Sea Toxics Monitoring Synthesis. Colton, J., Era-Miller, B., Godtfredsen, K., Hobbs, W., James, C.A., Luxon, M., Siegelbaum, H., eds. Puget Sound Ecosystem Monitoring Program. Tacoma, WA. 97 pgs

Download the full report

About the Author: 
The Puget Sound Ecosystem Monitoring Program is a collaboration of state, federal, tribal and local government agencies, non-governmental organizations, watershed groups, business, academic researchers, local integrating organizations, and other private and volunteer groups and organizations - all dedicated to monitoring environmental conditions in Puget Sound. The objective of PSEMP is to create and support a collaborative, inclusive, and transparent approach to regional monitoring and assessment that builds upon and facilitates communication among the many monitoring programs and efforts operating in Puget Sound. PSEMP’s fundamental goal is to assess progress toward the recovery of the health of Puget Sound.