Swimming beach at Green Lake closed after discovery of toxic algae
Aug 11, 2023, 6:16 PM

Sunset over Seattle's Green Lake (Photo courtesy of City of Seattle)
(Photo courtesy of City of Seattle)
The swimming beach at Seattle’s popular Green Lake has been shut down until further notice after toxic algae was discovered in the water.
Seattle Parks and Recreation released a statement Friday informing the public that King County Public Health had discovered the presence of the algae in the lake.
The county has yet to confirm how long the algae bloom will be present.
Park officials are asking residents and guests to not swim or water ski, not drink any lake water, keep pets away, clean fish well and discard guts and to avoid areas of scum when boating.
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For people, toxic algae can lead to skin rash, hives, and itchy eyes and throat, according to the Washington State Department of Health. For pets, exposure can lead to vomiting, seizures and convulsions.
City employees used a skimmer — a vacuum-like machine used to remove algae — when toxic algae appeared in other local bodies of water.
“We’re trying a couple of different approaches, very low-cost approaches – kind of quick and easy ways of greatly reducing the toxicity of this naturally occurring bacteria that’s in the water right now,” Doug Williams with the King County Department of Natural Resources previously told KIRO Newsradio.
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The county regularly tests the lake water for both toxic algae and bacteria at swimming beaches between June and September, according to The Seattle Times.
“The recent warm weather and rain events we’ve had make a really comfortable environment for cyanobacteria to grow,” Wafa Tafesh, a water quality planner at King County Department of Natural Resources and Parks, said, the paper reported.
Algae blooms look like a paint spill, slimy scum, foam, or clumps growing on the water, with colors varying from blue-green to reddish-brown to “pea soup green,” according to the state of Washington’s Department of Ecology.