Also known as “pond scum” or “moss,” this type of algae can form dense, hair-like mats on the water’s surface. If left untreated, the mats can cover the entire surface of the pond. There are many species of filamentous algae and often more than one species will be present at the same time in the pond.
Planktonic AlgaeChlamydomonas, Chlorella, Euglena, Closterium, Anacystis spp.
This type of algae is actually millions of microscopic plants that give the pond a “pea-soup” appearance. If left untreated, natural die-off in the fall may cause a fish kill.
Chara is easily identified by its crisp, gritty texture, musky odor and green needlelike structures that resemble leaves. These curious underwater plants are actually large algae growing in a form that makes them look like an advanced, flowering plant. Chara is a undesirable in ponds and lakes because it carpets the bottom and crowds out other species.
Pithophora belongs to the family of filamentous green algae. It may be found growing on the bottom or in dense mats on the surface of ponds. This algae is often described as resembling a tangled mass of cotton or wool-like growth which is very course to the touch. It may range in color from lime green to a dark greenish brown. The surface mats generally form in warmer weather when gas bubbles, produced by the plant, are trapped within the dense algal growth, causing them to become buoyant. Disturbance of these mats by high wind or heavy rain events may cause them to temporarily sink to the bottom. This often gives a false impression that the growth has “disappeared”, only to have it return to the surface within several days.