A study conducted on juvenile chinook salmon residing in the Fraser River estuary revealed the presence of various chemicals, including pharmaceuticals and flame retardants. Researchers gathered samples from numerous fish between 2019 and 2021, identifying over 80 contaminants solely in the salmon tissue, likely originating from industrial and wastewater sites upstream. Water samples from salmon habitat were also analyzed, uncovering 130 contaminants.
The research team expressed concerns that these chemicals may be adversely impacting the growth, behavior, and overall health of the chinook salmon. David Scott, the lower Fraser research and restoration director at the Raincoast Conservation Foundation (RCF), highlighted the connection between wastewater pollutants and fish contamination, citing a range of pollutants from pharmaceuticals and personal care products to pesticides and flame retardants.
The team monitored the Harrison River chinook stock, which matures in the Fraser River estuary, collecting samples from their tissue and habitat at various locations. The study identified 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 the other 15 priority contaminants, such as cocaine and pesticides, were detected in habitat water samples.
Additionally, eight “watchlist” chemicals posing elevated biological risks were discovered in salmon tissue samples, including pesticides, pharmaceuticals, and other organic chemicals. The study, primarily funded by the Department of Fisheries and Oceans and conducted in collaboration with the RCF and Simon Fraser University, underscored the significance of ongoing monitoring efforts.
Tanya Brown, a study co-author and assistant professor at Simon Fraser University, emphasized the likelihood of additional unmeasured chemicals affecting fish health, raising concerns about the combined exposure to various chemicals. Similar research in Washington state’s Puget Sound has shown that synthetic organic chemicals can hinder chinook growth, potentially leading to long-term impacts on the population and ecosystem.
The study’s findings may prompt improved management of chemicals through policy interventions and individual actions. Researchers stressed the importance of responsible pharmaceutical disposal as part of individual efforts to mitigate environmental contamination. The implications extend beyond the fish population, as these contaminants can impact marine mammals like southern resident killer whales, emphasizing the interconnectedness of environmental health across different species and ecosystems.