Filamentous Algae
Many species of filamentous algae are found throughout Maryland in both fresh and brackish water. The genus most common to the freshwaters is Hydrodictyon, while the most common nuisance filamentous algae found in brackish water is Entermorpha. Better known as waternet, Hydrodictyon is a filamentous type which resembles a net with five- to six-sided cell meshes-these nets are generally in the form of a flat sheet, although in some species they can form a cylindrical pouch. Waternet grows well in small ponds and in swamps; it occurs for the most part in hard water systems and is associated with high pH. Populations can become so dense as to interfere with fishing and swimming. Dense populations can cause oxygen depletion and give rise to offensive odor.