Alaskan fish are showing traces of pesticides that likely were never used in the state, according to new research.
A study by the National Park Service found the chemicals in fish at three Alaska parks — Lake Clark National Park, Wrangell-St. Elias National Park and Katmai National Park. The contaminants are carried from distant points on atmospheric currents, then brought down to earth with precipitation.
The study also examined contaminant levels in five national parks in the western US. It also found PCB concentrations, with loads in Alaska fish exceeding those in the Lower 48 sites. The Lower 48 parks in the study were Yosemite, Great Sand Dunes, Rocky Mountain, Lassen Volcanic and Sequoia and Kings Canyon.
The study was published in the April issue of the Journal of the American Water Resources Association. It reported results from several varieties of trout and some samples of Arctic char.
Contaminants found in the fish studied in Alaska’s parks tended to be dominated by older pesticides, while those in current use were more likely to show up in the fish in the Lower 48 parks, the study said.