Lake Erie: Signs of Trouble

By Sandy Bihn, Western lake erie Waterkeeper

»a green cup of water was the poster child of Lake Erie in 1970, and after nearly three decades, the same green water is back. Phosphorous in Lake Erie waters has increased every year since 1990. Researcher David Baker reports that the 2007 phosphorous readings are the highest in over 20 years.

In 1978 the U.S. and Canada signed a treaty setting limits for phosphorous pollution. The agreement resulted in the elimination of phosphorous in laundry detergents and discharge limits for wastewater treatment plants. As a result Lake Erie phos-

The invasive alga Lyngbya wollei piles up along the shores of Western Lake Erie. This satellite photo vividly shows algae and sediment pollution in the Great Lakes. Lake Erie (lower right) is the shallowest and warmest of the lakes — making it the most susceptible to algal blooms. Lake St. Clair (just above Lake Erie) is also heavily impaired by sediment and algae.

phorous levels dropped and the target was met in 1988. But the lowered phosphorous levels did not last long. In 1990 phosphorous was again on the rise. Today, Lake Erie waters are showing the same signs that harmed the waters and fish decades ago — dead zones and algae blooms.

Algae can take over a lake when fed too many nutrients and, in this case, too much phosphorous. In Lake Erie, a new invasive alga that appeared in summer 2006 called Lyngbya wollei is doing just that. It looks like matted wool and most likely came from boats that winter in the Southeastern U.S. Researchers hoped the February freeze would kill the unwelcome weed. But in April, mounds of algae remained piled up along the shoreline. This algae clogs shallow marinas where it gets into boat intakes and causes engines to shut down.

Lake Erie supplies drinking water to 11 million people and supports local economies with billions of dollars from sport fishing and recreation. But today Lake Erie needs help with phosphorous. Efforts in the 1970s to reduce toxics pouring into the Great Lakes have succeeded in reducing those pollutants. It’s now time to take nutrient pollution seriously. W