Harmful algal blooms (HAB) are one of the greatest threats to fresh water in the world. HABs happen when nutrients pollute water and feed algae or bacteria, causing them to multiply wildly, especially in warm, calm waters.

In the past, some lakes like Lake Erie were so polluted that policy makers had to act. In 1972, the United States and Canada signed the Great Lakes Water Quality Agreement, which resulted in yearly municipal phosphorus loads in Lake Erie to drop from 14,000 metric tons in 1972 to 2,000 metric tons in 1990.

Michigan EARTH Professor Gregory Dick weighed in on the issue."It was a great success story for science," Dick said. "We identified the nutrients, we used these policy interventions to reduce inputs to Lake Erie, and the blooms were dramatically reduced."

However, today Lake Erie faces a new problem: cyanobacteria.

"It could kill cows" in extreme doses, Dick said. "Large, large, large mammals. Livestock would be keeling over after drinking from a contaminated source of water. So, it's pretty toxic."

To read more about the issues affecting Lake Erie and possible solutions, read the full article at The Detroit News by clicking the button link below (requires subscription).