Several years ago, mercury levels in Great Salt Lake waterfowl were high enough to warrant a human consumption advisory for ducks. Today, the methylmercury is mostly gone. Researchers aren't exactly sure where the methylmercury went or what's to blame for elevated mercury levels in local wetlands.

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Several years ago, mercury levels in Great Salt Lake waterfowl were high enough to warrant a human consumption advisory for ducks. Today, the methylmercury is mostly gone. Researchers aren't exactly sure where the methylmercury went or what's to blame for elevated mercury levels in local wetlands.