Mercury increasing in northern pike, walleye
ST. PAUL — The amount of toxic mercury in northern pike and walleye in Minnesota has been unexpectedly rising since the mid-1990s, and a Minnesota Pollution Control Agency scientist says coal burning by other countries or climate changes may be the cause.
The MPCA reported the increase on Tuesday, after publishing a study in last week’s edition of the peer-reviewed journal "Environmental Science & Technology."
"In the decade before the mid-1990s, the methylmercury concentrations in northern pike and walleye from the great majority of Minnesota lakes were decreasing," said MPCA scientist Bruce Monson, who conducted the analysis. "However, the analysis showed that the fish-mercury concentration in the majority of lakes has been increasing since the mid-1990s."
The MPCA says the finding is a concern because methylmercury, the form of mercury in fish, is toxic to humans and wildlife.