Harmful Algal Bloom Confirmed in Bair Reservoir
Public Urged to Take Caution
A Harmful Algal Bloom (HAB) has been confirmed in Bair Reservoir near Checkerboard, Mont. When in doubt, stay out. Signage has been posted warning recreators to take precautions when swimming or wading in the water. Blooms can impact human health and sicken or kill livestock or pets.
Montana Department of Natural Resources and Conservation observed the bloom on June 28, 2023, and Meagher County collected water samples the following day. Three samples were collected at varying distances from the dam. Nostoc sp., a type of harmful algal species that can produce cyanotoxins, was identified in each sample. The samples were tested for anatoxin, a common type of cyanotoxin, and all samples returned “non-detect”.
Despite a lack of cyanotoxins present on June 29th, cyanotoxins can be produced at any time when a bloom is present and remain in the water column even after the bloom has visually dissipated. When in doubt, stay out. Do not drink, swallow, or swim in water that shows signs of a HAB and keep kids and pets or livestock out. Direct contact, ingestion, or inhalation of cyanotoxins may irritate the skin, eyes, nose, throat and respiratory system, or cause nausea, vomiting, diarrhea, headache, dizziness, muscle weakness, or liver and kidney damage. Rinse off with tap water immediately if you think you or a pet have come in contact with a HAB. If you suspect a HAB-related illness in a person or animal, including livestock, call your health care provider or veterinarian, or if it is an emergency, call Poison Control immediately at 1-800-222-1222.
Harmful algal blooms most often occur in Montana’s reservoirs and lakes, although water users should also be cautious about water flowing immediately downstream of a HAB. Common characteristics of HABs include green, blue, or gold coloration and the appearance of grass clippings or paint spilled on the water’s surface.
Harmful algal blooms happen when cyanobacteria, also known as blue green algae, rapidly grow out of control. These organisms are native to Montana and are naturally found at low, safe densities in many freshwater systems. HABs can form under certain conditions including when too many nutrients are available, when winds are low and water is calm, when the sky is clear and sunny and when the growing season is long or hot.
The Montana Department of Environmental Quality and Department of Public Health and Human Services maintains a website where people can submit reports of suspected HABs at: HAB.mt.gov
Before recreating in a waterbody, Montanans and visitors can check the website and view a map of all blooms reported, any health advisories or monitoring data associated with that report, and plenty of photos and information to educate yourself and others on what to look for. If you suspect a HAB, submit a report and state agencies will work with the local jurisdiction to monitor the incident. These reports are important for the health and safety of recreators and water users in the state, and they also help state agencies track where nutrient pollution may be an issue.
Tags: Press Release