Here’s some general information about blue-green algae from the DNR:
- Blue-green algae are in all water bodies in Wisconsin. Waters with high nutrient levels are more susceptible, but even lakes with excellent water quality may experience surface blooms, especially after periods of calm weather when wind can blow blue-green algae into 1 area of a lake.
- Blue-green algae can also grow on lake bottoms and rivers as mats, which sometimes float to the surface.
- It’s always a good idea to avoid swimming in areas with a lot of tiny particles in the water, opaque “pea soup” water, or dark-colored floating mats. All of these may be blue-green algae. Always avoid swallowing untreated surface water because it may contain bacteria, viruses, and parasites that could make people sick.
- If small children and dogs are swimming, choose the clearest water possible for them to swim in.
- Don’t let dogs swim or play in shallow, stagnant areas where blue-green algae mats may be growing on the bottom and dislodged by disturbance.
- Don’t let dogs eat floating material in the water, or material washed up on shore.
- In dogs, water intoxication (from swallowing too much water) and heat stroke share symptoms with blue-green algae poisoning. Give dogs plenty of breaks from playing and retrieving in lakes, and give them flat objects for retrieval instead of balls. Always provide shade and fresh, clean water to drink, and wash them off with clean water after they swim, so they don’t lick blue-green algae from their coats.
There’s more information at:
https://dnr.wi.gov/lakes/bluegreenalgae/ and
https://www.dhs.wisconsin.gov/water/bg-algae/index.htm.
Margaret Gesner, MS Health Officer, Central Racine County Health Department
10005 Northwestern Avenue Franksville, WI 53126 Phone: 262-898-4460 (main number)