Hot Lake Turns Green

Harmful algae in Lake Erie, Monroe, MI, 22 July 2011 (photo from NOAA Coast Watch Great Lakes Node)
Harmful algae in Lake Erie, Monroe, MI, 22 July 2011 (photo from NOAA Coast Watch Great Lakes Node on Flickr)

If you’re planning to swim in Lake Erie anytime soon, check the harmful algae advisories before you do.

This summer the toxic algae bloom near Toledo got a head start in late June. It usually doesn’t get thick until September but the bloom started early this year.  The photo above, from July 2011, shows what the water can look like this early in the season.

A 1 July 2018 satellite photo shows how much of the lake turned green.

Satellite MODIS image of Lake Erie, 1 July 2018 (image from NOAA Coast Watch Great Lakes Node)
Satellite MODIS image of Lake Erie, 1 July 2018, 18:18 GMT, 2:18pm EDT (image from NOAA Coast Watch Great Lakes Node)

(Click here for the above image with locations marked including Presque Isle, Cleveland, Magee Marsh, Toledo.)

It even closed beaches near Cleveland.

Harmful algae blooms are triggered by a combination of factors, one of which is water temperature. Lake Erie is certainly hot.  The surface temperature from Toledo to Cleveland was 80+ degrees F yesterday, as warm as bath water.  (Purple is bad on this map.)

Great Lakes Water Temperature, 5 July 2018 (image from NOAA Great Lakes CoastWatch)
Great Lakes Water Temperature, 5 July 2018 (image from NOAA Great Lakes CoastWatch)

The problem at each beach comes and goes, however, because the wind moves the algae around.  By July 5 the harmful algae bloom had moved away from shore to the middle of the lake (except in Sandusky Bay).  Click here for the 5 July 2018 bulletin.

What should you do?

This poster from Ohio EPA shows how to recognize harmful algae blooms. Click on the graphic to download the poster.

How to Recognize Harmful Algae Blooms, poster from Ohio EPA

Harmful algae blooms aren’t only a problem at Lake Erie.  They can happen in a pond near you.

p.s.  What about Lake Erie at Presque Isle State Park, Pennsylvania?
As of this writing there wasn’t a problem for humans, but they issued a dog swimming advisory on 29 June 2018 for two bayside locations because dogs are susceptible to a lower toxin level and they drink while they swim. Click here for the dog swimming advisory.

(images from NOAA Great Lakes CoastWatch; click on the images to see the originals. Or click here for the latest satellite images and here for photos on Flickr)

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