Algae Outbreak in NE Montana Waters

Thursday, July 30, 2020

Last week, Montana Department of Environmental Quality (DEQ) notified Montana Fish, Wildlife & Parks of a blue-green bloom at Bailey Reservoir Fishing Access Site in Hill County. These algal blooms are not uncommon in waters across northeast Montana as we head into late summer and early fall. These outbreaks are known as Harmful Algal Blooms (HABs), as they sometimes pose health risks for people, pets, livestock, and wildlife.

HABs are caused by blue-green algae that are native to Montana’s freshwater lakes and reservoirs, according DEQ, They are not Aquatic Invasive Species. Scientists believe the blooms are occurring at more locations, however, with increased frequency and longer duration than they have in the past. Causes may include warmer water temperatures, longer summer growing seasons and increased nitrogen and phosphorus runoff from a variety of human activities.