Trout contain high levels of mercury

BOISE - Idaho is known for its pristine rivers.  But one of its most protected is polluted.

Silver Creek, south of Hailey, appears crystal clear but the trout within it are carrying dangerous levels of toxins.

Ironically, much of this popular river is owned by the Nature Conservancy of Idaho -- an agency whose sole purpose is to protect ecologically important lands and waters.

This was the Conservancy's very first project in Idaho, dating back to 1975 when it bought its first 500 acres along the river.

As part of its stewardship of Silver Creek, it regularly monitors the water and the fish. 

Results of a recent study it commissioned showed elevated levels of mercury in some brown trout -- levels up to four times higher than what's considered healthy.

"It is alarming, but I think it also show that if you hunt, if you fish, if you breath...clean water and clean air matter and so we have to find solutions to address those clean water and clean air problems," said Matt Miller, Nature Conservancy.

The Nature Conservancy this week asked the Department of Environmental Quality to figure out where this mercury is coming from.

One possible source could be coal-fired power plants that emit mercury into the air -- which then lands on the water and is eaten by the fish.

Silver Creek attracts anglers from all over the world because it has one of the highest densities of trout in North America -- 5,000 trout per mile -- and that agency would like to maintain bragging rights that those fish are fresh and healthy.