About Algae

Algae are primitive plantlike organisms that are capable of photosynthesis but lack true leaves, stems, roots and vascular systems. Photosynthesis is the process by which green plants transform light energy into chemical energy. Photosynthesis uses light to split water, amounting to the same thing as irradiation. A catalyst such as chlorophyll gives ordinary sunlight the destructive potency of x-rays. The waste product is oxygen.

During respiration, oxygen is used and carbon dioxide is released. While respiratory release of carbon dioxide can depress pH, carbon dioxide removal by photosynthesis reduces acidity and can increase pH of water. pH scale is logarithmic. A pH of 5.5 is 10 time more acidic than water at a pH of 6.5. Thus, changing the pH by a small amount (suddenly) is more of a chemical change than might first appear.

All algae have chlorophyll a, but differ in their accessory pigments, pigments that trap wavelengths of light to which chlorophyll a is not as sensitive. The mixture of pigments in the chloroplasts lends characteristic colors related algae. Many scientific and common names of algal phyla are based on these colors (the Chlorophyta, or green algae, for example).

Characteristics of Some Phyla

Blue-green algae are often mistakenly classified as algae because of the chloroplasts contained in the cells. These organisms are photosynthetic bacteria and fall under the group of Cyanobacteria.

Chlorophyta (green algae) and Cyanobacteria (blue-green algae) contain species that are fairly common fresh water foulers. An example of Chlorophyta is Sprirogyra, a slimy filamentous algae, and Microcystis is an example of Cyanobacteria. Ultrasonic waves have successfully controlled both of these species.

Web Sites of algae images are posted on the Useful Links page.

- By JoAnn Sanborn, February 2, 2011 -