Juvenile chinook salmon in the Fraser River estuary have been found to contain a range of chemicals, including pharmaceuticals and flame retardants, according to a recent study. Researchers gathered samples from hundreds of fish over a two-year period and discovered more than 80 contaminants in the salmon tissue alone, believed to originate from industrial and wastewater sites upstream. Water samples from the salmon habitat also revealed the presence of 130 contaminants.
The research team expressed concerns that these chemicals could be negatively impacting 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 diverse array of pollutants found in the fish, ranging from pharmaceuticals and personal care products to pesticides and flame retardants.
The study, which focused on organic chemicals, identified 16 priority contaminants with potential adverse effects, such as the flame retardant PBDE-penta-total found in salmon tissue samples. Additionally, 15 other priority contaminants, including cocaine and pesticides, were detected in the habitat water samples. Eight “watchlist” chemicals posing elevated biological risks were also discovered in the salmon tissue samples, including pesticides, pharmaceuticals, and other organic chemicals.
Funded mainly by the Department of Fisheries and Oceans and conducted in collaboration with the RCF and Simon Fraser University, the study revealed that there may be more chemicals affecting the fish that were not screened for. Tanya Brown, a study co-author and assistant professor at Simon Fraser University, emphasized the alarming combination of chemicals the fish are exposed to, pointing out the vast number of high-volume use chemicals in the marketplace that are not thoroughly monitored.
Similar research conducted in Washington state’s Puget Sound has shown that synthetic organic chemicals can inhibit chinook growth, potentially leading to long-term impacts on the population. This has implications not only for the salmon themselves but also for marine mammals like the southern resident killer whales that feed on them. The research findings on chemical contamination in salmon could help shape future management strategies, whether through public policies or individual actions to mitigate the effects of these pollutants.