The shallow, sunny waters of the reflecting pool are an ideal incubator for algae growth in the summertime. Experts say the ...

Glaciers are huge white ice masses that can reflect a lot of sunlight. However, especially where the glaciers are not covered in snow and the bare ice is exposed, they sometimes have dark patches.

Florida officials are asking people to avoid contact with the water in Lake Okeechobee where blue-green algae was tested.

A) Green snow, B) Red snow, C) Snow algae (members of the green algae), which are the main cause of green snow, and D) Parasitic chytrid infecting snow algae. Parasitic chytrids causes host death.