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 collected samples from hundreds of fish over a two-year period and identified over 80 contaminants in the salmon tissue alone. The pollutants are believed to originate from industrial and wastewater sites upstream. Water samples from salmon habitat were also analyzed, revealing the presence of 130 contaminants.
The research team expressed concerns about the potential negative impacts of these chemicals on 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 range of pollutants found, including pharmaceuticals, personal care products, pesticides, and flame retardants.
The study identified 16 priority contaminants with harmful effects, such as organic chemicals and pharmaceuticals, with the flame retardant PBDE-penta-total being detected in salmon tissue samples. Additionally, 15 other priority contaminants, including cocaine and pesticides, were found in the water samples from the salmon habitat. Eight additional “watchlist” chemicals that pose elevated biological risks were also discovered in the salmon tissue samples, consisting of pesticides, pharmaceuticals, and other organic chemicals.
Funded by the Department of Fisheries and Oceans, the study was conducted in collaboration with the RCF and Simon Fraser University. Tanya Brown, a study co-author and assistant professor at Simon Fraser University, emphasized the need for continued monitoring of the chemicals affecting the fish, pointing out that there may be additional undisclosed chemicals of concern beyond the ones studied.
In a related initiative, research in Washington state’s Puget Sound has been tracking contaminants in fish habitat for over three decades. Molly Shuman-Goodier, a research scientist with the Washington Department of Fish and Wildlife, highlighted the inhibitory effects of synthetic organic chemicals on chinook salmon growth, potentially leading to long-term impacts on the population.
The study’s findings are crucial not only for understanding the impacts on chinook salmon but also for considering the implications for other species, such as southern resident killer whales that feed on these fish. The high contaminant levels found in the chinook salmon could have repercussions for human health as well, exceeding the human health threshold set by the Washington State Department of Health. Researchers on both sides of the border emphasized the importance of managing chemicals effectively, whether through public policies or individual actions, to mitigate the risks posed by these contaminants.