Blue-green algae blooms have been observed in Lake Nokomis and Powderhorn Lake in the last week

Potentially harmful algae blooms (HABs) may occur in other lakes this fall

September’s hot and sunny weather has contributed to blue-green algae blooms that have been observed in Powderhorn Lake and Lake Nokomis in the last week; other lakes have the right conditions for blue-green algae blooms, as well.

Some types of blue-green algae can produce toxins can make humans and animals sick: These are known as Harmful Algae Blooms (HABs). Blue-green algae blooms are often described as looking like pea soup or spilled green paint (images and info here).

Most blooms are not harmful, but it’s not possibly to tell if a blue-green algae bloom is toxic just by looking at it. That’s why it’s recommended that people and pets stay out of the water when these blooms or algae scum are visible. Water conditions change quickly and wind can easily move scum around a lake, so it is not possible to post all locations where blooms occur.

Seasonal weather and algae blooms

Fall algae blooms are unusual but are becoming more common as the region becomes seasonally warmer on average. This is not a Minneapolis-only phenomenon. Other lakes in the metro area and region are having the same issue.

Protect people and pets: Learn to recognize blue-green algae

To reduce your exposure or your pet’s exposure to blue-green algae:

Don’t let animals swim or drink where there is noticeable algae in the water or scum on the shore.

* Note: Dogs are not allowed in Minneapolis water bodies, per MPRB ordinances.

More information 

MDH: Preventing Harmful Algal Bloom-Related Illness
www.health.state.mn.us/diseases/hab/prevention

MDH Fact Sheets [PDFs}

English: Harmful Algal Blooms (HABs)

Español: Harmful Algal Blooms (HABs)

Hmoob: Harmful Algal Blooms (HABs)

Soomali: Harmful Algal Blooms (HABs)