Cooling off during 4th? Watch for toxic algae

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You may be thinking about cooling off on the water this July 4th holiday weekend.

But there is something to watch out for before you take that dip: toxic algae.

With hot spring temperatures leading into a warm summer so far, we could see more algae blooms on lakes around the northwest. There have been several beach closures already this season.

Not all blooms are toxic, but if they are, exposure can make people and pets very sick.


“People need to be out watching for themselves,” said Debra Bouchard who leads King County Water Quality. “We only sample 22 beaches in King County, but there’s a lot more access points that people can be getting in the water.”

Bouchard says calm, warm days can create the environment for algae that produces toxins, which then float and accumulate on the surface.

Scientists monitor for two types of toxins. Exposure to one can lead to flu like symptoms, but the other is more serious and can cause breathing difficulties and in extreme cases, death.

Seattle’s Green Lake has been a hot bed of algae blooms.

Toxic algae closed Green Lake to swimming for a time last summer and this year, for the first time in twelve years, the lake was treated with Alum, a chemical that prevents algae.

But other bodies of water, including Lake Washington are too big to treat.

Scientists are relying on people to report any algae blooms they see this summer.

To stay safe, you should never take a dip in the water if you see an algae bloom, and also report it here.

Bouchard says the slogan should be, “When in doubt stay out.”