By Ophelia Océane
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The Great Lakes hold 20 percent of the world’s fresh surface water. The good news is that legacy contaminants are decreasing more quickly than previously reported in three of the Great Lakes, but have stayed virtually the same in two other lakes, according to new research. Polychlorinated biphenyls (PCBs), the pesticide DDT and other banned compounds dropped about 50 percent in fish in Lakes Michigan, Ontario and Huron from 1999 through 2009, although there were no significant changes in Lakes Superior and Erie fish, according to the study to be published this month in Science of the Total Environment.

 

“These are very positive results. The lakes are improving and slowly cleaning themselves up,” said Thomas Holsen, co-director of Clarkston University’s Center for the Environment and co-author of the study. “Even with the decreases, it will be 20 to 30 years until the decades-old contaminants in Great Lakes fish decline to the point that consumption advisories can be eliminated,” Holsen said.

 

All good news, except as we clean up the old chemicals like Polychlorinated biphenyls (PCBs), the pesticide DDT and other banned compounds they are being replaced by newer ones, such as flame retardants that are building up in fish and wildlife and chemicals we are not yet even looking for from oil and gas development.

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