Grays Harbor County officials on Tuesday warned of a blue-green algae bloom at Vance Creek County Park south of Elma.

Cyanobacteria, or blue-green algae, blooms when the temperature, sunlight and nutrient conditions are right. Some blue-green algae cause toxic blooms that can cause serious illness in people or be fatal to pets, birds and other animals, according to the Washington State Department of Health.

The Grays Harbor County Environmental Health Division confirmed the cyanobacteria bloom in Pond No. 2 on Monday at Vance Creek Park.

“When you see algae, don’t swim, wade, paddleboard or fish. Keep in mind as wind direction changes, the algae could move elsewhere in the lake,” reads a warning on the county website.

“Bowers Lake is not affected at this time,” the warning states.

Toxic algae can make you sick within minutes to hours, according to a release from the county. Symptoms include weakness, vomiting, diarrhea, nausea and rash.

If your pets experience lethargy, vomiting, diarrhea, convulsions or difficulty breathing, the release states, you should talk to a veterinarian.

Warning signs at Pond No. 2 tell people not to swim in the areas with scum and not to drink the water. It says to “keep pets and livestock away” and to “clean fish well” and discard any internal organs.