Juvenile chinook salmon in the Fraser River estuary have been found to contain a variety of chemicals, including pharmaceuticals and flame retardants, according to a recent study. The research, conducted between 2019 and 2021, involved collecting samples from hundreds of fish and analyzing over 80 contaminants present in the salmon tissue. The pollutants are believed to originate from industrial and wastewater sites upstream. Additionally, water samples taken from the salmon habitat revealed the presence of 130 contaminants.
The research team, led by David Scott from the Raincoast Conservation Foundation (RCF), expressed concerns about the potential negative impacts of these chemicals on the growth, behavior, and overall health of the chinook salmon population. Among the pollutants detected were pharmaceuticals, personal care products, pesticides, and flame retardants.
The study, which focused on organic chemicals, identified 16 priority contaminants with harmful effects, including PBDE-penta-total, a flame retardant found in salmon tissue samples. The remaining 15 priority contaminants, such as cocaine and pesticides, were detected in the habitat water samples. Additionally, eight “watchlist” chemicals posing elevated biological risks were found in the salmon tissue, including pesticides, pharmaceuticals, and other organic compounds.
Funded primarily by the Department of Fisheries and Oceans and conducted in collaboration with the RCF and Simon Fraser University, the study highlighted the need for further monitoring of the chemicals affecting the fish. Tanya Brown, a co-author of the study and assistant professor at Simon Fraser University, emphasized the alarming combination of chemicals the salmon are exposed to, pointing out that there are likely many more unmeasured chemicals of concern.
Similar research in Washington state’s Puget Sound has shown that synthetic organic chemicals can hinder chinook salmon growth. Molly Shuman-Goodier, a research scientist with the Washington Department of Fish and Wildlife, emphasized the potential long-term impacts on the salmon population. The findings also raise concerns about the implications for other species, including southern resident killer whales, which feed on chinook salmon carrying high contaminant loads.
The study’s results may influence future management strategies for chemicals, whether through public policies or individual actions. Researchers suggest that being mindful of how pharmaceuticals are disposed of can help mitigate the impact of these pollutants on the environment and wildlife.
