Algae on Water Supplies

By and large the answer is yes. But there are some variations to be included.

Algae and cyanobacteria are tiny organisms that occur naturally in saltwater and freshwater. Individual organisms can often only be seen under a microscope, although with some species, individuals can join together to form colonies visible to the naked eye. It is important to understand the similarities and differences between algae and cyanobacteria as both groups can have distinct impacts on surface water quality.

Algae is beneficial in the simplest manner because algae release oxygen as part of their metabolism, they serve to oxygenate the water. Green algae are preferred because blue-green algae float on the surface and are associated with water quality problems. Algae also play an important part in the aquatic food chain, as they are the main food source for zooplankton and small fish, which in turn serve as food for larger fish and other wildlife. To have more algae in the water means that more carbon dioxide is used from the atmosphere and that more oxygen is released into the atmosphere. Algae require warmth, sunlight, and nutrients to grow and reproduce. They are found in the upper 200-300 feet of ocean water. The upper layer of water, known as the epipelagic zone, is rich in oxygen, penetrated by sunlight, and warmer than water at lower levels.

Algae, specifically the type of algae that exists in a specific water source can also be beneficial in another manner. Algae are good indicators of the atrophic status of a water body, that is, the degree of pollution and nutrients in that water. A lake dominated by green algae and diatoms is relatively "clean" oligotrophic water, whereas dominance by bloom-forming blue-green algae indicates a more polluted or eutrophic condition, typically caused by the troublesome Cyanobacteria.

Cyanobacteria are members of a group known as eubacteria or true bacteria. For a long time they were not recognized as bacteria, more often being referred to as blue-green algae. All bacteria belong to a group of organisms known as prokaryotes, a Latin word meaning 'before nucleus'. Bacteria have no organized nucleus. Cyanobacteria are classified as bacteria, not algae, since their genetic material is not organized in a membrane-bound nucleus. Unlike other bacteria, they have chlorophyll and use the sun as an energy source. They are often referred to as 'blue-green' since the first cyanobacteria identified were bluish-green in color. However, not all members are in this color. Some are olive or dark green, and others are even purplish in color.

Cyanobacteria occur naturally in surface waters. Although their size is usually microscopic, when conditions are ideal, both can undergo a phenomenon known as bloom. This results when the algae reproduce rapidly and the individuals form clumps visible to the naked eye.