A recent study revealed the presence of various chemicals, including pharmaceuticals and flame retardants, in juvenile chinook salmon residing in the Fraser River estuary. Researchers gathered samples from numerous fish over a two-year period and identified over 80 contaminants solely in the salmon tissue, with industrial and wastewater facilities upstream believed to be the main sources. Water samples from the salmon habitat also showed the detection 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 at the Raincoast Conservation Foundation (RCF), highlighted the concerning presence of pollutants ranging from pharmaceuticals and personal care products to pesticides and flame retardants in the fish.
The study focused on the Harrison River chinook stock developing in the Fraser River estuary, analyzing their tissue and habitat at various locations. According to the findings, 16 of the revealed chemicals were classified as “priority” contaminants with potential adverse effects, including organic chemicals and pharmaceuticals. Notably, the flame retardant PBDE-penta-total was the sole priority contaminant identified in the salmon tissue, while the remaining 15, including cocaine and pesticides, were detected in the habitat water samples.
Additionally, eight “watchlist” chemicals posing elevated biological risks were found in the salmon tissue samples, comprising pesticides, pharmaceuticals, and other organic substances. The study, primarily funded by the Department of Fisheries and Oceans and conducted in collaboration with the RCF and Simon Fraser University, underscored the need for further monitoring due to potential exposure to unexamined chemicals.
Tanya Brown, a study co-author and assistant professor at Simon Fraser University, emphasized the alarming combination of chemicals affecting the fish, pointing out that there are likely numerous other chemicals not screened in the research that could be of concern. The study’s implications extend to Puget Sound in Washington state, where similar investigations have been ongoing for over three decades, revealing the inhibitory effects of synthetic organic chemicals on chinook growth.
Moreover, researchers warned of potential long-term impacts on the ecosystem, particularly on southern resident killer whales that heavily rely on chinook salmon as a food source. The study findings could influence future chemical management strategies, whether through policy implementation or individual actions, like proper disposal of pharmaceuticals to mitigate environmental contamination risks.
