Tuesday, September 21, 2010

Here come the algae

by Jani Gilbert, communication manager, Eastern Regional Office

It’s that time of year again, when the Washington Department of Ecology (Ecology) asks residents near local lakes to keep children and animals away from the water because of blooms of toxic blue-green algae.

The algae have spread widely in the Suncrest area of Lake Spokane, and could also be in other parts of the lake. Ecology also has reports of blooms in Newman Lake, east of Spokane.

Samples have been taken in Lake Spokane to determine the toxicity of the algae, but algae can change daily into a toxic or non toxic state.

The results of one water sample collected from Lake Spokane early last week indicate algal toxins (microcystin) are present at 58.3 parts per billion. Above six parts per billion microcystin is considered by the state Department of Health to be a level at which warnings should be issued so that people don’t drink the water, swim in the water or let their pets play in the water.

Microcystin is found most often in the scum that people can see on top of the water. As cells die, toxins are released into surrounding waters. Some toxins, such as microcystins, are very stable and can remain in the water for days or weeks after the bloom has disappeared.

The key is to stay away from it, don’t let kids play in it, and don’t let pets or livestock drink from scummy water. They are most at risk.

This time of year blooms are common in Newman and Spokane lakes as well as at Potholes Reservoir and Liberty Lake.

Algae blooms happen mostly in the summer or fall, but can occur anytime. Blue-green blooms can float to the surface and be several inches thick near the shoreline. Sometimes the blooms can be dispersed. They often look like green paint floating on the water.

Blue-green algae blooms pose a human health concern and have killed animals after exposure in some Washington lakes. No illnesses have been reported from the current blooms in Lake Spokane and Newman Lake.

Although many blue-green blooms are not toxic, some blue-green algae produce nervous system or liver toxins, but it's hard to predict. A single species of algae can have both toxic and non-toxic strains.

See the entire news release.

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