Recreational use and toxin advisories went into effect at Keyhole State Park this month after more of the harmful cyanobacterial blooms, otherwise known as blue-green algae, were spotted in two separate parts of the reservoir last month.
Recreational use advisories were issued on Aug. 19 for the Rocky Point and Wind Creek areas of the reservoir, based on samples collected Aug. 16, according to the Wyoming Department of Environmental Quality map of statewide algae blooms.
The bloom advisories in Keyhole are two of 26 harmful cyanobacterial bloom advisories issued throughout Wyoming this summer.
Those same Keyhole blooms also warranted toxin advisories, which were issued on Sept. 3 and indicate the algae bloom samples tested conclusively for dangerous levels of toxins, which also means that people and pets should avoid contact with the blooms.
The toxin advisories at Keyhole are two of five toxin advisories issued by the state Department of Environmental Quality this summer.
Park goers and their animals are advised to avoid water in the areas with harmful cyanobacterial blooms. The park remains open through the advisories, which remain in place until the blooms dissipate or the end of summer recreation season comes on Sept. 30.
The Wind Creek area of the reservoir also tested positive for harmful cyanobacterial blooms this winter, in a rare instance of blue-green algae being discovered beneath the ice.
The blooms, which also occurred in Keyhole Reservoir last August, more typically occur in late summer when a combination of warm temperatures and still water create an environment for the bacteria to proliferate.
People are advised to avoid water in the area of the blooms, especially where it can be seen densely. They shouldn't ingest the water. Boiling, filtering or otherwise treating the water will not remove the toxins, according to the recreational use advisory.
Animals are especially at risk and should avoid the water near the blooms. If they do come into contact with the algae or nearby water, their owners should rinse them off and contact a veterinarian, the advisory warns.