Video: The pond scum that can kill
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: