MOSES LAKE — The Grant County Health District is warning everyone to avoid contact with the waters of Moses Lake after district officials found potentially dangerous blue-tree algae in samples from across Moses Lake.

“It is likely Blue-Green algae is present in all parts of Moses Lake,” said Heather Massart, public information officer for the health district.

On Monday, Sept. 17, the district said it took samples from Blue Heron Park, Cascade Park, Montlake Park, Connelly Park and the Sand Dunes and confirmed the presence of blue-green algae “toxin levels higher than the Washington State recreational guidelines.”

“(The Health District) has posted warning signs around Moses Lake that will be up until the Lake is clear of the toxic algae,” Massart added.

Last week, the district issued a warning for a north-western stretch of Moses Lake from Connelly Park west to the Fish and Wildlife boat launch.

The district is advising people not swim or engage in any recreation activities that would put them in contact with the water. In addition, people are advised not to drink lake water or let their pets or livestock drink the lake water, and are also advised to thoroughly clean any fish caught in the lake, taking special care to dispose of the guts.

The health district said it will continue to test the lake weekly until sample results show toxins are below the Washington State recreational guidelines.

According to the health district, the kind of blue-green algae — which is really a very ancient bacterium — found in Moses Lake produces Microcystin toxin, which can cause severe liver damage.

Symptoms of toxin poisoning include may include jaundice, shock, abdominal pain, weakness, nausea and vomiting, severe thirst, rapid or weak pulse and death, and can appear anywhere from 30 minutes to 24 hours after exposure.

“These algae blooms grow rapidly in fresh water when there is enough sunlight, high temperatures, and nutrients in the water,” the district said in a news release. “It often looks like green paint floating on the water. It is common for Grant County waters to have blue-green algae in the summer and fall, but not all blue-green algae blooms are toxic.”

Charles H. Featherstone can be reached via email at countygvt@columbiabasinherald.com