Harmful algal bloom warning issued for Beaver Creek Reservoir

Montana Department of Environmental Quality issued an update Friday on caution advisories on harmful algal blooms that included Beaver Creek Reservoir on the north end of Beaver Creek Park about 8 miles south of Havre.

People are warned to use caution at the reservoir to avoid exposure to potential harmful algal blooms and to keep pets out of the areas where they see algae.

Harmful algal blooms, commonly called blue-green algae, can potentially be harmful to both people and animals, she added.

The blooms are created by accumulations of cyanobacteria and can create toxins. If the toxins make contact with the skin they could possibly cause skin irritation, rashes, hives or blisters on the skin. If they are ingested it could also cause liver and kidney issues, respiratory symptoms and in some animals can cause seizures. 

Toxins do not always occur with a harmful algal bloom, but it's impossible to tell without taking water quality samples. When in doubt, it's best to stay out, officials warn.

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.

The algae is naturally occurring and also breaks down naturally, if conditions are good. If an area has elevated levels of nutrients, such as runoff from fertilizer or grazing areas, along with warmer temperatures, stagnant still water and sunlight the algae could grow rapidly.

Harmful algal blooms have been reported in the area, including at Beaver Creek Reservoir, multiple times in recent years.

The algae can be identified by its colors, like pea soup or grass clippings, and an oily ring around the algae. The algae also floats on top of the water, with a very distinct look to it.

If anyone spots the blue-green algae they should not touch it or be near it. They should report it immediately to the county.

People can learn more about harmful algal blooms and also report suspected occurrences of harmful algal blooms online at https://dphhs.mt.gov/publichealth/Epidemiology/hab .