http://ipraudio.interlochen.org/Mercury.mp3
A new study of mercury in the Great Lakes region says the problem has significantly improved in recent decades. But in a few places it appears to be getting worse. That could include northern Michigan.
Mercury has been a problem in the Great Lakes regions for much of the past century. Coal-fired power plants and incinerators have been the main sources. Mercury accumulates in fish that are eaten by people and birds. It can impair brain development in children.
A newreportfor the Great Lakes Commission says there is a lot less mercury in the ecosystem generally, especially in the Great Lakes themselves. That makes sense because of stricter clean-air laws.
The study draws together findings from 35 different research papers. Dave Evars, from the Biodiversity Research Institute in Maine, was one of the lead scientists on the project.
"I think the great news that I see for game fish species like walleye and largemouth bass is that there's a significant decline," says Evars.
But the research also suggests some places are especially sensitive to mercury pollution. So walleye in Lake Michigan are less toxic these days but mercury levels in walleye in some inland lakes in Wisconsin are up. In general the Great Lakes themselves are faring better than inland lakes. The research also suggests forested areas with wetlands, like northern Michigan, are more susceptible to pollution. The acidity of water also could play a role.
The report was released at the start of an international conference in Detroit this week focusing on the Great Lakes.