Utah and local officials issued a fish consumption advisory for channel catfish caught in the Green River's Desolation Canyon.
"Elevated mercury levels have been found" in the channel catfish there, posing a health concern. Levels of the contaminant were not high enough to justify an outright ban. Instead, officials said adults should limit consumption to no more than two 8-ounce servings per month.
Also, "women who may become pregnant, pregnant women, nursing mothers and young children should not eat more than one 4-ounce serving per month" from this source. A 4-ounce serving is about the size of a deck of cards.
Earlier, limits were advised on consuming largemouth bass from Gunlock Reservoir in Washington County, and brown trout from Mill Creek, Grand County. In September state officials recommended against eating northern shoveler and common goldeneye ducks from the Great Salt Lake's marshes because of mercury.
The element is found in rocks and minerals, and is released when coal is burned. It can work its way into waterways and concentrate in some fish species.