Several Minneapolis lakes are susceptible to algae blooms in Autumn. Learn to recognize blue-green algae, which can be harmful for people and pets.
Posted on 19 September, 2023Blue-green algae can grow in lakes during many different seasonal conditions. Some species of blue-green algae are stimulated by fall lake conditions.
Currently, Powderhorn Lake, Lake Hiawatha and Lake Nokomis are experiencing algae blooms, with other lakes having the right conditions for potential blue-green algae blooms.
Some types of blue-green algae can produce toxins can make humans and animals sick and are known as Harmful Algal Blooms (HABs). Blue-green algal blooms are often described as looking like pea soup or spilled green paint (images and info here). However, you can’t tell if a bloom is harmful by looking at it, so it is recommended that people and pets stay out of the water when these blooms or algae scum are visible. Water conditions change quickly and scum is moved easily by wind, so it is not possible to post all locations where blooms occur.
Fall algae blooms 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 the region are having the same issue.
To reduce your or your pet’s exposure to blue-green algae:
- Avoid or minimize recreating or making body contact in waters that appear to have a blue-green algae bloom. If you do come in contact with algae-laden water or scum, wash with fresh water afterward.
- Don’t let animals swim in or drink water where there is noticeable algae or scum on the shore.
* Note: Dogs are not allowed in Minneapolis water bodies, per MPRB ordinances.
More information
Blue-green algae and harmful algal blooms (Minnesota Pollution Control Agency)
Preventing Harmful Algal Bloom-Related Illness Minnesota Department of Health (MDH)
MDH Fact Sheets