A recent study has revealed the presence of numerous chemicals in juvenile chinook salmon residing in the Fraser River estuary, including pharmaceuticals and flame retardants. Researchers conducted extensive sampling between 2019 and 2021, identifying over 80 contaminants solely in the salmon tissue, suspected to originate from industrial and wastewater sources upstream. Water samples from the salmon habitat also showed traces of 130 contaminants.
The team expressed concerns that these chemicals could be adversely affecting 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 wide range of pollutants found in the fish, ranging from pharmaceuticals to pesticides and flame retardants.
Monitoring the Harrison River chinook stock in the Fraser River estuary, researchers collected tissue and habitat samples from various sites. The study identified 16 “priority” contaminants, such as organic chemicals and pharmaceuticals, with potential adverse effects. One priority contaminant detected in salmon tissue samples was the flame retardant PBDE-penta-total. Additionally, 15 other priority contaminants, including cocaine and pesticides, were found in the water samples from the habitat.
Furthermore, eight “watchlist” chemicals posing elevated biological risks were observed in the salmon tissue samples, consisting of pesticides, pharmaceuticals, and other organic compounds. The study was primarily funded by the Department of Fisheries and Oceans and conducted in collaboration with the RCF and Simon Fraser University.
Tanya Brown, a study co-author and assistant professor at Simon Fraser University, emphasized that there could be additional unexplored chemicals affecting the fish, beyond the research’s focus on organic chemicals. She stressed the alarming nature of the combination of chemicals the fish are exposed to.
Similar research in Washington state’s Puget Sound has indicated the inhibition of chinook growth by synthetic organic chemicals. Molly Shuman-Goodier, a research scientist with the Washington Department of Fish and Wildlife, highlighted the potential long-term impacts of these contaminants on chinook salmon.
The study’s findings have implications for higher trophic levels, such as southern resident killer whales that prey on chinook salmon. These whales exhibit high contaminant levels, reflecting the accumulation of pollutants through the food chain. The study suggests that managing these chemicals, whether through public policies or individual actions, is crucial for environmental and human health protection.