Late Summer at the Lake? Watch for blue-green algae

by Jani Gilbert, communication manager, Eastern Regional Office

Photos: Lake Spokane

Caution!

Go ahead! Enjoy your late summer swim in the lake! But avoid areas where the water looks like scummy green paint. It's probably a bloom of blue-green algae and sometimes it contains toxins.

The algae blooms show up every year in many of our lakes and even rivers, often in late summer or early fall when the water is warm, sunshine is abundant and the weather is calm. Although many blue-green blooms are not toxic, some blue-green algae produce nerve or liver toxins.

People should stay away from it, kids should not be allowed to play in it, and livestock should be kept away too. Dogs should not be allowed to play in water that has a bloom and has not been tested.

Here is what to look for:

Blue-green algae cells are very small and they don’t clump together, although they can look like a mat. They are hard to pick up or hold.

• In calm weather, the paint-like scum forms on the water surface. It can be either bright green or blue-green.
  
  
• If the weather turns windy, the algae will be mixed in the water, making it look like pea soup.

Blue-green blooms can float to the surface of the water and be several inches thick near the shoreline.

See more information about freshwater algae.

Read complete news release.

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