The Wyoming Department of Health has issued recreational use advisories for Boysen Reservoir, Ocean Lake, Saratoga Lake, Wheatland Reservoir #3, and Leazenby Lake due to harmful cyanobacterial blooms (HCB). 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 waterbody 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.

Potential blooms were identified by satellite imagery from the Cyanobacteria Assessment Network (CyAN) or reported to the Wyoming Department of Environmental Quality. The Wyoming Department of Environmental Quality visited the lakes and reservoirs on July 29, 2020 and collected water samples. Cyanobacteria densities exceeded the 20,000 cells/mL recreational use threshold 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 lakes and reservoirs. 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 This email address is being protected from spambots. You need JavaScript enabled to view it. or (307) 777-5825.

Questions regarding cyanobacteria sampling can be directed to Michael Thomas, Natural Resource Analyst, Wyoming Department of Environmental Quality, at This email address is being protected from spambots. You need JavaScript enabled to view it. or (307) 777-2073, or Lindsay Patterson, Surface Water Quality Standards Coordinator, Wyoming Department of Environmental Quality, at This email address is being protected from spambots. You need JavaScript enabled to view it. or (307) 777-7079.