What are algae? The term ―algae encompasses a wide range of plant life forms of which some grow on land (terrestrial forms which are found in soil, on trees and even on exposed rocks) and some grow in water. Of the latter some algae are marine forms (saltwater / oceanic types which include minute plankton to huge seaweed masses) and some are freshwater forms. Growth of algae appears in many colors from the common green form to yellow-green, blue-green, brown, black, and even red. Algae may thrive in ponds, lakes and municipal reservoirs, especially where water flows are minimal or quiescent. Since most of us are more familiar with the freshwater forms of algae which are commonly known as pond scum or simply as slime, this article will confine itself to a discussion of the still broad spectrum of freshwater aquatic algae, some of its causes for g growth, and probably most importantly to waterway owners: a description of what can be done to control the growth of algae in a subsequent newsletter?

Aquatic algae range from single cell microscopic forms to multi-cellular forms and to the more complicated forms which resemble submersed plants. Many authorities classify algae into (1) the planktonic types, which are the simplest forms and are made up of single cells or small colonies of algae cells; (2) the more complicated filamentous types which consist of chains of algae cells joined together to form thread-like structures and which can attach to waterway sediments where unsightly floating mats may develop; and (3) the macrophytic algae types, the most complex of the aquatic algae, of which some have been confused with aquatic plants since they develop stems and root structures in waterway sediments. Of the many types of algae, the macrophytic Chara and Nitella forms may provide a favorable submersed environment measures to control these algae forms should be tempered with the possible risk of altering the underwater environment.

It should be emphasized that while mankind and especially waterway owners may view all forms of algae (similar to noxious aquatic weeds) as troublesome, as unappealing eyesores, and potentially toxic to other life forms, algae nevertheless provide a number of otherwise beneficial and significant contributions to waterways. In common with most plant forms, aquatic algae’s living processes produce oxygen and utilize carbon dioxide during daylight hours (a process which is ―reversed at night); many types of algae utilize nutrients from within and thereby rid them from waterways; and algae provide food for many forms of animal life.

The negative aspects of excessive algae growth, often referred to by the term algae blooms (primarily attributed to a rapid, uncontrolled proliferation and often harmful overgrowth of both the planktonic and filamentous forms) include the depletion of aquatic oxygen levels in waterways when algae die and decompose. Decreased oxygen levels are detrimental to the survival of other aquatic plant and animal life forms. Some forms of blue-green algae are toxic to animals which drink algae contaminated water; these type algae can also cause public drinking water supplies to become almost non-potable.

Summer in Florida brings Daylight Savings Time along with all the factors required for algae growth and for damaging harmful algae blooms: increased sunlight essential for algae’s photosynthetic life processes; longer days; increased temperatures; and sporadic rainfall. With all those conditions currently in existence, it is almost inevitable for increased algae growth and the potential for harmful algae blooms to occur.

As a result of the aging changes of waterways in conjunction with the possible detrimental effects of excessive algae growth and their decomposition products, those water bodies undergo a recently described process known as eutrophication-a unique process which may present difficult problems for many waterway owners and managers to solve.

Algae exist worldwide in all marine and fresh waters and therefore cannot be totally eliminated from those natural water bodies. To illustrate the adaptability of those prolific plants to a broad range of environmental factors, algae have been found in the boiling temperatures of hot springs as well is in the near freezing waters of the Antarctic. Conditions affecting algae growth are multifold hence many of these need to be considered if any degree of algae control is to be successful. Since algae forms are so diverse and so widespread it may also be more appropriate to consider ―algae control in terms of ―algae management.

Since algae require sunlight for their photosynthetic life processes, specially formulated blue dyes have been utilized to limit the growth of mat forming algae in deeper waters.
The more ―conventional management of the growth of algae and of ―algae blooms involves chemical herbicides which have been made specifically to target algae and are appropriately termed algaecides. Among the more effective cell toxic algaecides are the liquid and granular copper products as well as the contact acting liquid and granular endothall. Algaecide usage, however, must be carefully customized to the type of targeted algae and to the amounts applied since dead and decomposing algae cells and mat producing algae deplete oxygen levels vital for fish survival in waterways being treated.

Physical management of algae can be effected by the use of aluminum sulfate (alum) to precipitate phosphorus, a vital element for algae growth. Another more ―environmentally and esthetically friendly method of physically managing algae growth is by the installation of mechanical aerators. These bubble producing aeration devices, marketed by Charles Aquatics, Inc., increase oxygenation levels of waterways thereby improving fish habitat and aid in preventing the release of certain forms of phosphorus essential for algae growth from waterway sediments.

A newer, environmentally ―friendly, and very effective physical method of managing all forms of algae is with the installation of an electrically powered sonic wave producing device into algae infested waterways ranging in size from lakes, ponds, municipal reservoirs, and swimming pools. The LG Sonic device, also sold by Charles Aquatics, Inc., has been successfully used to manage algae in the Jacksonville area as well as in many other parts of the world.

Mechanical methods to manage algae growth are of limited effectiveness and have been primarily aimed at the collection of dead algae mats which float to the waterway surface.
Of the biological management methods for algae, the manipulation and/or reduction of nutrients essential for algae growth into waterways are currently considered by authorities as the ―environmentally ideal approach for algae control over the long term. While young triploid grass carp may feed on mat forming algae and tilapia have been found to be somewhat effective in algae control, regulation of the amounts of nutrients, particularly phosphorous and to a lesser degree, nitrogen, introduced into waterways have been shown by extensive research to be the most effective means of algae growth management.

Control of algae and algae blooms can be very difficult and requires an aquatic management service which can best be provided by Charles Aquatics, Inc.