It cost $9 million to construct an electronic barrier to keep Asian carp out of Lake Michigan. Asian carp can weigh up to 100 pounds and can daily eat up to 40 percent of their body weight.
Over-fishing and gravel mining in riverbeds have wiped out 99 percent of the population of sturgeon, the largest native fish in the Great Lakes.
Thomas Kitchin & Victoria Hurst/All Canada Photos/Getty Images
Billions of gallons of sewage runoff is dumped into the Great Lakes every year.
43 hot spots There are 43 pollution hot spots in the Great Lakes region that the United States and Canada call areas of concern.
Pulp and paper mills, such as the one pictured here on the Kaministiquia River at the head of Lake Superior, are contributors to point-source pollution that leaches harmful chemicals into nearby water, altering water quality and the overall health of the ecosystem. According to Health Canada, a Canadian government department that works to promote the health of Canadian citizens, the “whole bleached pulp mill effluent� that these mills produce has been linked to harmful biochemical and physiological changes in fish downstream.
1 dead zone One dead zone develops in Lake Erie nearly every summer.
fall 2009 LSA n 15