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. Researchers gathered samples from hundreds of fish over a two-year period and identified more than 80 contaminants in the salmon tissue alone, with industrial and wastewater sites upstream believed to be the sources. Water samples from the salmon habitat 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 wide range of pollutants discovered in the fish, ranging from pharmaceuticals and personal care products to pesticides and flame retardants.
The study, which focused on Harrison River chinook stock in the Fraser River estuary, detected 16 “priority” contaminants with potential adverse effects, such as organic chemicals and pharmaceuticals. One of the priority contaminants found in salmon tissue samples was the flame retardant PBDE-penta-total, while the remaining 15, including cocaine and pesticides, were found in the habitat water samples. Additionally, eight “watchlist” chemicals posing elevated biological risks were detected in the salmon tissue samples, including pesticides, pharmaceuticals, and other organic chemicals.
Funded primarily by the Department of Fisheries and Oceans and conducted in collaboration with the RCF and Simon Fraser University, the study raised concerns about the exposure of fish to unmeasured chemicals beyond those screened for in the research, particularly organic chemicals. Tanya Brown, a study co-author and assistant professor at Simon Fraser University, emphasized the alarming combination of chemicals impacting the fish.
Similar research conducted in Washington state’s Puget Sound has revealed a long-term tracking of contaminants in fish habitat, showing evidence of synthetic organic chemicals inhibiting chinook growth. This raises concerns about potential long-term impacts on the fish population and their predators, such as the southern resident killer whales that rely on chinook salmon as a food source. The findings underscore the importance of managing chemicals effectively through public policies and individual actions to protect both marine life and human health.