Cyanobacteria bloom confirmed at Keyhole

The Wyoming Department of Health has issued a recreational use advisory for Keyhole Reservoir due to a harmful cyanobacterial bloom (HCB).

On August 10, the Wyoming Department of Environmental Quality received a report from Keyhole State Park of dog illnesses that were potentially linked to cyanobacteria exposure. The Wyoming Department of Environmental Quality visited the reservoir on August 12 and collected water samples.

Cyanobacteria densities were found to exceed the 20,000 cells/mL recreational use threshold as identified in Wyoming’s HCB Action Plan. Cyanotoxin results are pending. The Wyoming Department of Health is working directly with resource management agencies to ensure that signs are posted at the reservoirs.

HCBs are also referred to as harmful algal blooms (HABs) since cyanobacteria are commonly known as blue-green algae.

The Department of Health issues advisories to inform the public that there may be health risks for people and animals in areas where HCBs occur. Lakes and reservoirs under a recreational use advisory are not closed since HCBs may only be present in certain areas of the water body and conditions can change frequently.

The advisory will remain in place until the bloom has fully dissipated and cyanotoxin concentrations are below recreational use thresholds identified in Wyoming’s HCB Action Plan, or until the primary recreation season ends on September 30th, whichever comes first.

The status of advisories in Wyoming as well as other HCB resources can be found at WyoHCBs.org.

If you encounter a potential HCB, the Wyoming Department of Health and Wyoming Livestock Board recommend the following:

Avoid contact with water in the vicinity of the bloom, especially in areas where cyanobacteria are dense and form scums.

Do not ingest water from the bloom. Boiling, filtration and/or other treatments will not remove toxins.

Rinse fish with clean water and eat only the fillet portion.

Avoid water spray from the bloom.

Do not allow pets or livestock to drink water near the bloom, eat bloom material, or lick fur after contact.

If people, pets, or livestock come into contact with a bloom, rinse off with clean water as soon as possible and contact a doctor or veterinarian.

Questions about health effects and recreational use advisories can be directed to Dr. Karl Musgrave, State Environmental Health Epidemiologist / State Public Health Veterinarian, Wyoming Department of Health, at [email protected] or (307) 777-5825.

Questions regarding cyanobacteria sampling can be directed to Michael Thomas, Natural Resource Analyst, Wyoming Department of Environmental Quality, at [email protected] or (307) 777-2073, or Lindsay Patterson, Surface Water Quality Standards Coordinator, Wyoming Department of Environmental Quality, at [email protected] or (307) 777-7079.