NDSU Extension warns of green, blue-green scum
FARGO, N.D. (AP) -- The North Dakota State University Extension Service is warning residents and ranchers to watch out for green or blue-green scum in livestock water supplies, lakes and other recreational waterways.
Water quality associate Roxanne Johnson says algae blooms can have an offensive odor and appearance, but they also can be fatal to livestock, pets and people. She says not all algae blooms are toxic, and it's impossible to identify poisonous species without laboratory analysis.
Johnson says the seasonal event is not algae but a photosynthetic bacteria called cyanobacteria that rely on sunlight for energy. As they store energy, they create a tiny cavity of air that allows them to move up and down in the water to areas with more nutrients.
Bacteria numbers increase with warm weather, calm winds and nutrients.