Blue-Green Algae in Lake Superior?? Yes!

Blue-Green Algae in Lake Superior?? Yes!

A news release out of Bayfield, Wisconsin July 23, 2012, reported a blue-green algae bloom had developed from Cornucopia to Little Sand Bay along the south shore of Lake Superior.

Unfortunately, blue-greens can produce toxins in concentrations that can harm people if the contaminated water is swallowed.

Blue-green algae blooms typically develop in warmer waters containing an overabundance of nutrients such as phosphorus.  Although the bloom dissipated relatively quickly, that it developed at all in Lake Superior is sobering.  Lake Superior, with its cold water and few nutrients would seem immune to such outbreaks.

The heavy rain events of June in part of the Lake Superior watershed washed lots of nutrients and sediments into the lake.  That, combined with warmer than normal conditions, apparently triggered the blue-green outbreak.  Blue-green algae often are blue-green in color but can also be blue, green, reddish, purple or even brown.

What to do to reduce risk from these potentially dangerous toxins:

  • Don’t swim in water that looks like pea soup or paint or has scum or puffy floating blobs.
  • Be aware that wading, water skiing, or even windsurfing can also pose risks.
  • The most common symptoms are stomach or respiratory problems and rashes, but more serious consequences are possible, even death in extreme circumstances.

What can we do to reduce the likelihood of blue-green blooms?  Reduce the amount of phosphorus that goes into lakes.

Important note: phosphorus loading into lakes is seven to nine times greater from lakeshore lawns that directly reach the water’s edge without a buffer than lawns separated from the water by a wide buffer of native plants.

Darby Nelson

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