Juvenile chinook salmon in the Fraser River estuary have been found to contain a variety of chemicals, including pharmaceuticals and flame retardants. Between 2019 and 2021, researchers collected samples from hundreds of fish and identified over 80 contaminants in the salmon tissue alone, believed to originate from industrial and wastewater sites upstream. Water samples from salmon habitat also revealed the presence of 130 contaminants.
The research team expressed concerns that these chemicals could be adversely affecting the growth, behavior, and overall health of the chinook salmon. David Scott, the lower Fraser research and restoration director for the Raincoast Conservation Foundation (RCF), highlighted the wide range of pollutants found in the fish, from pharmaceuticals and personal care products to pesticides and flame retardants.
The study, conducted on Harrison River chinook stock in the Fraser River estuary, detected 16 “priority” contaminants with potential adverse effects, including organic chemicals and pharmaceuticals. Notably, the flame retardant PBDE-penta-total was found in salmon tissue samples, while other priority contaminants, such as cocaine and pesticides, were identified in habitat water samples.
Furthermore, eight additional “watchlist” chemicals posing elevated biological risks were discovered in salmon tissue samples, including pesticides, pharmaceuticals, and other organic chemicals. The study, largely funded by the Department of Fisheries and Oceans and conducted in collaboration with the RCF and Simon Fraser University, emphasized the need for continued monitoring and research to understand the full extent of chemical exposure in fish populations.
Tanya Brown, a study co-author and assistant professor at Simon Fraser University, expressed concerns about the presence of potentially unmeasured chemicals affecting the fish. The combination of various chemicals to which the fish are exposed was described as alarming, given the vast number of chemicals in the marketplace.
Similar research in Washington state’s Puget Sound has shown evidence of synthetic organic chemicals inhibiting chinook growth, with potential long-term impacts on salmon populations. The implications extend to the broader ecosystem, as chinook salmon serve as a vital food source for southern resident killer whales, which are known to have high contaminant loads. Additionally, human consumption of chinook salmon from Puget Sound raises concerns, as the organic chemical levels exceed human health thresholds set by authorities.
Scientists on both sides of the border emphasized the importance of this research in shaping future chemical management strategies, whether through public policies or individual actions. Addressing the disposal of pharmaceuticals was highlighted as a practical step individuals can take to minimize chemical impacts on the environment and food chain.
