Algae Scum
Various genera
Visible colonies
Aquatic ecosystem
In the summertime, many bodies of water in the temperate zone contain a population of algae, appearing as coloration in the water from associated pigments. These can be scummy and look like paint spilled on the surface of the water.
“Innumerable microscopic algae help anchor aquatic ecosystems; they turn sunlight into food, and themselves serve as food for water-dwelling frogs, fish, snails, and insects.” – Marion Renault