Duffus in NYT: PCB threat to whales is shocking, but not surprising
Dr. Dave Duffus, founder and Director of UVic's Whale Research Lab, commented on the dire threats facing killer whales in a recent article featured in the New York Times. Duffus has been researching whales over a lengthy field-based and professorial career, looking at whale ecology in the Pacific Northwest, as well as the growing visibility of the consequences of whale-human interactions. The article points to recent research findings in Science, which indicate that whales in more industrialized areas are at particularly high risk of population collapse from PCBs, in addition to the myriad other threats stacked against these animals. Duffus said the conclusions of the study are "shocking," but adds that he doesn't doubt them.
The concentration of PCBs in the whales is a result of bioaccumulation. As explained in the article, "Whales sit at the top of their food chain. Chemicals like PCBs are taken up by plankton at the base of the food chain, then eaten by herring and other small fish, which are themselves eaten by larger fish, and so on. At each step in this chain, PCBs get more and more concentrated." The toxins are stored in the blubber of the whales, who are at the top of this chain. These are then passed from mother to calf. The highly public death of a local calf brings this crisis to mind.
The killer whales in the Pacific Northwest and Clayoquot Sound region, bombarded by underwater noise, contaminants, and changes in their food supply, are no exception. Duffus remarked that "you can see the downtrend in their population."
Read the full article here.
