Hydrodictyon
Hydrodictyon is usually found as floating masses in hardwater lakes and slow flowing streams of temperate and tropical environments. It has not been found in colder regions. In the springtime, Hydrodictyon sometimes forms noticeable but harmless blooms on the surfaces of freshwater ponds and small lakes. Eutrophic conditions often contribute to excessive growth. Visible masses are common near rice paddies, fish farms, irrigation ditches, and other areas with high nutrient levels, and can accumulate along the edges of waterbodies and clog boat intake valves. These growths can be difficult to control since Hydrodictyon is relatively tolerant to the copper treatments used to prevent blooms. Hydrodictyon reticulatum is the most common of the several described species.
Research has shown that cells of Hydrodictyon and the other mat-forming green algae Pithophora and Spirogyra are composed of 18-26% protein, which is comparable to the amounts found in certain vegetables and cyanobacteria. Although presently harvested only for use as mulch and fertilizer, these and other algae may represent a potential food source for the future.