Flame Retardants in Wild Juvenile Chinook
PBDEs in all 11 Major Puget Sound Estuaries
In the spring of 2016, WDFW’s long term contaminant monitoring program found PBDEs in juvenile Chinook salmon at all of the 11 major Puget Sound estuaries they sampled.
Why PBDEs are a Problem
PBDEs (polybrominated diphenyl ethers) are a class of flame retardant used since the 1970s in consumer and industrial products including textiles, polyurethane foam, wire insulation, and plastics.
By the end of 2013, the use of PBDEs in new products was largely phased out, but many older products and some new products continue to release PBDEs into the environment which can eventually end up in our waterways. PBDEs are a long lasting pollutant, similar to PCBs (polychlorinated biphenyls).
Low levels of PBDEs can harm juvenile salmon by increasing disease susceptibility and altering hormone production. In the spring of 2016, WDFW’s long term contaminant monitoring program found PBDEs in juvenile Chinook salmon at all of the 11 major Puget Sound estuaries they sampled. In parts of the Snohomish Estuary, PBDE levels in wild Chinook were significantly higher than other areas of the river basin, and in some cases, above the level known to cause health problems for juvenile salmon. Wild Chinook, versus hatchery raised, are known to spend more time in the estuary, subjecting them to higher risk of PBDE exposure.
For juvenile Chinook undergoing a critical growth period before migrating through Puget Sound, we predict that high contaminant exposure likely impacts survival during their seaward migration.
PBDE Focus Area
Long Live the Kings and our partners are working to identify PBDE hotspots in important salmon habitat in order to focus our efforts.
The Snohomish River Estuary is an area where threatened wild Chinook are known to linger during an important stage in their lifecycle. Wild juvenile Chinook caught in the lower mainstem portion of the Snohomish river estuary had higher levels of PBDEs compared to hatchery Chinook collected at the same location and Chinook caught in other areas of the Estuary. Additional analysis suggested that PBDEs in wild juvenile Chinook are associated with municipal wastewater, but we are still working to confirm the pathway(s).
Two wastewater facilities have discharge pipes in the estuary, but the most contaminated fish were caught in the area where the City of Everett discharges a portion of its wastewater. There may be a number of explanations for this, such as that other unidentified pathways exist, the Everett facility experiences higher PBDE inputs than other facilities, wild Chinook behavior in the lower Snohomish results in greater PBDE exposure, suboptimal water treatment is occurring, or a combination of these or other factors.
Finding Solutions
Over the past decade, scientists have learned more about the effects of PBDEs on aquatic species, especially salmon and orca which are federally protected. Further, they have learned that one of the largest pathways for PBDEs in Puget Sound appears to be publicly owned water treatment facilities.
Currently, in Washington State there are no regulatory requirements to monitor or limit PBDE levels in effluent from municipal wastewater treatment facilities, although National Marine Fisheries Service has recommended PBDE monitoring in another treatment facility in the state.
In the short-term, Long Live the Kings is working with the City of Everett, Tulalip Tribes, Dept. of Fish and Wildlife, Snohomish County and Dept. of Ecology to further investigate PBDEs in the Snohomish Basin and develop strategies to evaluate and address the problem. Initial actions include: piloting steps to minimize PBDE loading in the lower Snohomish and additional PBDE testing. Ultimately, the group will gain a better understanding of how juvenile Chinook adsorb PBDEs, how PBDEs are distributed throughout the watershed, and potentially, identify PBDE sources.