What is that green slime on my lake?

The green slime is caused by Cyanobacteria. Cyanobacteria are microbes that live in water and produce energy from the sun (photosynthesis). They are found almost everywhere on Earth—from oceans and lakes to temporarily moistened rocks in deserts. Cyanobacteria created the first oxygen in Earth’s atmosphere, ultimately making human life possible. Now, due to our actions that are warming the planet and altering water quality, they are blooming more frequently and poisoning our lakes and rivers in the process.

Science Museum of Minnesota scientists are conducting studies of Minnesota lakes to better understand when, where, and why Cyanobacteria cause harmful blooms. This information will help the state protect its beloved waters.

To learn more about Cyanobacteria and human activities, check out the short video below produced by the museum’s St. Croix Watershed Research Station and popular YouTube channel MinuteEarth.

The video was funded by The McKnight Foundation.