The Pond Scum that Can Kill (Video) (IMAGE) American Chemical Society Caption You've probably seen that pesky greenish stuff floating on lakes and ponds. Usually this pond "scum" is just a nuisance. But sometimes it is a horde of cyanobacteria -- also known as blue-green algae -- that can blossom into a harmful algal bloom capable of releasing all sorts of deadly poisons into the environment. In the latest Speaking of Chemistry, Sophia Cai jumps in the pond to teach you all about these blue-green menaces: https://youtu.be/kNL99XVJjQo. Credit The American Chemical Society Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.