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 phosphorous 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 |
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.
(NASA)
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