Tuesday December 12, 2023
Oregon Public Broadcasting —
A popular catch for anglers on the Snake River in Idaho and Oregon could have higher levels of mercury, depending on where it’s reeled in. A new study found mercury concentrations in smallmouth bass are affected by some dams.
The U.S. Geological Survey’s study was published in the journal “Environmental Science & Technology.”
Researchers with the USGS found smallmouth bass behind reservoirs in the Snake River had twice the amount of mercury concentrations as fish found in free-flowing stretches of the river, higher than U.S. Environmental Protection Agency standards. The study also found some fish up to 10 miles downriver from dams showed higher mercury levels.
The study tested 31 sites along 530 miles of the river, just upriver from Lewiston to Pocatello, both in Idaho.