And the problem isn’t going away; their PCB levels have stayed the same for about three decades. Similarly, average PCB levels in the fish of the Upper Hudson have not changed significantly in recent years, according to the Environmental Protection Agency.
“There are just a lot of PCBs here and they don’t break down,” Jahn said. “Sediments, water, fish, birds, bats, shrews, insects, mink, everything we study in the Hudson River is contaminated with PCBs.”
The contamination is a concern for the mink farms scattered throughout the region.
Michael Whelan, executive director of Fur Commission USA, a trade association for fur farmers, said chemical concerns are one reason that mink farmers in upstate New York don’t feed much fish to their animals.
“The food is localized in most cases. In some Great Lakes states and the Pacific Northwest farmers may use some wild fish in the feed,” Whelan said. “But in places like upstate New York, they mix in more cheese, beef and poultry now.”
However, domestic mink that escaped farms had higher PCB loads than their wild counterparts along Lake Erie, in a 2012 study from researchers in Canada. While they could have been fed tainted food at the farms, it’s possible that escaped mink aren’t good hunters and eat things more likely to be contaminated, said Jeff Bowman, a research scientist at Trent University and the lead author of the study.
“We watched one mink – an escaped mink that had some of the highest PCB levels – walk up and down the beaches at Lake Erie eating zebra mussels, which filter sediment” that is highly contaminated, Bowman said.
Adult mink also may be at risk. In addition to the kit deaths, researchers linked the PCBs-tainted Hudson River fish to jaw lesions and altered organ sizes in adults.
The mink research will be used to help determine if cleanup efforts at the river should include specific provisions to help the animals recover. Increased dredging of sediment, dam removal and adding more plant cover are all possible remedies, Jahn said. Dredging, funded by General Electric under a Superfund cleanup, already has begun on sections of the upper river.
This article originally ran at Environmental Health News, a news source published by Environmental Health Sciences, a nonprofit media company.