Juvenile chinook salmon in the Fraser River estuary have been found to contain a variety of chemicals, including pharmaceuticals and flame retardants, according to recent research. The study, conducted between 2019 and 2021, analyzed samples from hundreds of fish and identified over 80 contaminants in the salmon tissue alone. The researchers attribute the contamination to industrial and wastewater sources upstream. Water samples from the salmon habitat also revealed the presence of 130 contaminants.
Researchers 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), emphasized the impact of wastewater pollutants on the fish, noting a range of pollutants from pharmaceuticals and personal care products to pesticides and flame retardants.
The study, which focused on Harrison River chinook stock in the Fraser River estuary, identified 16 priority contaminants with potential adverse effects, including organic chemicals and pharmaceuticals. One such priority contaminant, PBDE-penta-total, was found in salmon tissue samples. Additionally, 15 other priority contaminants, such as cocaine and pesticides, were detected in habitat water samples. Furthermore, eight “watchlist” chemicals, posing elevated risks, were found in salmon tissue samples, including pesticides, pharmaceuticals, and other organic chemicals.
Funded primarily by the Department of Fisheries and Oceans and in collaboration with the RCF and Simon Fraser University, the study highlighted the need for further monitoring due to the presence of unmeasured chemicals that the fish might be exposed to. Tanya Brown, a study co-author and assistant professor at Simon Fraser University, emphasized the alarming combination of various chemicals affecting the fish.
Similar research conducted in Washington state’s Puget Sound over the past three decades has revealed the inhibitory effects of synthetic organic chemicals on chinook growth. Molly Shuman-Goodier, a research scientist with the Washington Department of Fish and Wildlife, stressed the potential long-term impacts on chinook populations due to these contaminants.
The implications extend beyond fish populations, as chinook salmon are a vital food source for southern resident killer whales. These whales, known to have high contaminant loads, are at risk due to the pollutants present in their prey. Additionally, human health concerns arise as organic chemical levels in Puget Sound chinook surpass established thresholds. Researchers on both sides of the border believe that this research can guide better management of chemicals through public policies and individual actions, such as responsible disposal of pharmaceuticals.
