A range of chemicals, including pharmaceuticals and flame retardants, have been discovered in young chinook salmon residing in the Fraser River estuary. Over 80 contaminants were identified solely in the salmon tissue from samples collected between 2019 and 2021, with the suspected sources being industrial and wastewater facilities located upstream. The research team also analyzed water samples from the salmon habitat, uncovering 130 contaminants.
According to David Scott, the lower Fraser research and restoration director for the Raincoast Conservation Foundation (RCF), the wastewater that enters rivers contains various pollutants that end up in fish, affecting their growth, behavior, and overall well-being. The team focused on the Harrison River chinook stock that matures in the Fraser River estuary, investigating multiple sites for tissue and habitat samples.
A recent study funded mainly by the Department of Fisheries and Oceans, in collaboration with the RCF and Simon Fraser University, revealed 16 “priority” contaminants with potential adverse effects, such as organic chemicals and pharmaceuticals. Notably, the flame retardant PBDE-penta-total was found in the salmon tissue, while the other 15 priority contaminants, including cocaine and pesticides, were detected in the habitat water samples. Additionally, eight “watchlist” chemicals, associated with increased biological risks, were found in the salmon tissue samples, comprising pesticides, pharmaceuticals, and other organic substances.
Tanya Brown, a study co-author and assistant professor at Simon Fraser University, emphasized that there are likely more chemicals affecting the fish that were not screened in the study, which primarily focused on organic compounds. The combination of these various chemicals poses a significant concern for the well-being of the fish.
In a related study conducted in Washington state’s Puget Sound, researchers have monitored contaminants in fish habitats for over three decades. Their findings suggest that synthetic organic chemicals may impede the growth of chinook salmon, potentially leading to long-term impacts on their population dynamics. Furthermore, the research underscores the importance of managing chemicals effectively, whether through public policies or individual actions, to mitigate the risks posed to the environment and human health.