A preliminary ranking of contaminants of concern in juvenile Harrison Chinook and their habitat in the Fraser River, British Columbia.

• Main Author: Lo, Bonnie
• Format: Text
• Language: English
• Published: Western CEDAR 2022
• Subjects: Fraser River; First Nations
• Online Access: https://cedar.wwu.edu/ssec/2022ssec/allsessions/311; https://cedar.wwu.edu/context/ssec/article/3473/viewcontent/360_43d1a7b717ac460cab5bd9aca8cd16f5.pdf

The Fraser River (British Columbia) was once considered one of the world’s most productive salmon rivers. This river is home to 19 Chinook populations which represent an important species not only to First Nations, recreational anglers and commercial fisheries but also to Southern resident killer whales. The Harrison River Chinook stock, which numerically dominate the lower Fraser River stocks, spend 30-50 days in the Fraser River estuary, where they feed and grow prior to entering the marine environment. This stock was selected as a focal stock due to its spawning location origin in the lower Fraser River, and because ocean type Chinook are believed to rely most heavily on estuarine habitat compared to “stream type” Chinook. The lower Fraser River and estuary is heavily impacted by many anthropogenic activities including forestry, mining, pulp and paper, wood preservation, chemical manufacturing, urban and agricultural runoff and wastewater (sewage) treatment. Despite a history of pollution inputs into the lower Fraser River and estuary, little is known about contaminant exposure and their associated health impacts in Chinook salmon. A preliminary ranking of over 600 contaminants of concern, including various pesticides, PCBs, PBDEs, flame retardants, pharmaceuticals and personal care products, and metals in Harrison juvenile Chinook and their habitat (water and sediment) was conducted. Samples were collected from three impacted sites within the estuary and two reference sites. A combination of exposure activity ratios, risk quotients, and toxicity quotients were applied across the different matrices. This initial ranking of contaminants will serve to identify those contaminants suspected of driving observed health effects in the real world that will be further explored in a field health effects study. Results from this research will be used to inform Chinook conservation, recovery, and management efforts, especially as they relate to Fraser River Chinook and Southern Resident killer whales.