Field Notes

We encourage you to make the best decisions for your family and pets over the upcoming Fourth of July weekend… and enjoy the lakes as much as possible! Here are some things you should know about blue-green and green algae in order to do that:

When aquatic weed control specialists spray for plants, they are typically targeting rooted plants and not blue-green or green algae. When those plants die, they decay in the water. That leads to extra nutrients that can lead to future algae growth.

Not every algae bloom on our lakes has toxin in it, but some do. (It’s not completely clear under what circumstances algae produces toxin, and that’s what the Lilly Center is studying.) If you see a bloom, IDEM recommends that you stay out of the water. The toxin level is unknown. This is especially true for pets, because they are more likely to accidentally drink lake water or eat algae, and they’re more susceptible to blue-green algae toxin.

Green algae does not produce toxin. There are ways to tell blue-green and green algae apart! Green algae can look like stringy or silky mats attached to or caught up in other aquatic plants on or beneath the surface. Blue-green algae tends to look like a paint spill on the surface, or greenish blobs of “paint” made up of microscopic algae cells. Here’s a helpful website that shows pictures of each.

You can learn more about what blue-green algae is and what circumstances it tends to thrive in by visiting the following posts:

If you want to keep learning, we’re covering all of this and more in a free webinar in late July. Sign up today!