What are Algae?
Algae Types Before and After
Algae are a wide variety of photosynthetic plants that occur in a wide
range of environmental habitats. As plants they contain chlorophyll and
have simple reproductive structures. Unlike most plants, their tissues are
not differentiated into true roots, stems or leaves. They range from single
cells to fairly complex multi-cellular organisms. Some algae, like Chara,
have such a complex structure that they are mistaken for vascular plants.
An individual microscopic single cell algae plant is about 0.001 mm in
diameter or about 25 times smaller than a human hair. Algae are found
throughout the world and are a general nuisance in water treatment plants,
drinking water supplies, irrigation reservoirs, fish ponds, water impoundments,
water gardens, swimming pools, and cooling towers.
These microscopic single-celled forms of plant life thrive in sunshine.
They are present on vegetation, in the air, in the soil, and in water.
Their microscopic spores are continuously introduced into pools and other
bodies of water by wind, dust storms, rain showers, etc.
They grow rapidly in stagnant waters when exposed to sunlight and temperatures above 39ºF. They can form
objectionable slime and odors. They can interfere with filtration systems and irrigation nozzles. They can greatly increase
chlorine demand in pools and cooling tower systems. Phosphates and nitrates in the water from fertilizer and land runoff
encourage their growth.
Algae have three basic forms: Planktonic, filamentous and macrophytic. Planktonic algae are single-celled, microscopic
plants that float freely in the water. When these plants are extremely abundant or an algal bloom occurs, they make the
pond water turn green. Less often, they can turn the water other colors, including yellow, gray, brown or red.
Filamentous algae are sometimes referred to as "thread algae" or "pond scum." Filamentous algae occur as fine green
threads that form floating mats, which are often moved around the pond by wind. These algae are also commonly found
attached to rocks, submerged trees, other aquatic plants and boat docks.
Macrophytic algae resemble true plants in that they appear to have stems and leaves and are attached to the bottom. A
commonly-occurring macrophytic type of algae is called chara or musk grass due to its strong musky odor. Chara feels
coarse to the touch, because of lime deposits on its surface, earning it another common name -- stonewort.