Accession Number : ADA067600

Title :   The Role of Algae in Aquatic Ecosystems,

Corporate Author : OFFICE OF THE CHIEF OF ENGINEERS (ARMY) WASHINGTON D C

Personal Author(s) : Gangstad,E. O.

Report Date : 01 APR 1979

Pagination or Media Count : 28

Abstract : Algae occupy a unique position in the aquatic world because they utilize light energy in the process of reducing CO2 to the oxidation state of cellular carbon. Algae are the ultimate source of both cellular carbon and chemical energy for other organisms, and because of this are often called primary producers. The oxygen released by algae and oxygen uptake by aeration are the two major sources of oxygen in flowing surface waters. In addition, algae assimilate large amounts of nutrients and trace metals during the growing season. Detection and analysis of an algal problem can be accomplished by remote sensing, enumeration of phytoplankton, chlorophyll A measurements and carbon-14 uptake measurements. Once a problem is detected, an algicide, such as copper sulfate, is applied. The treatment of a lake with copper sulfate is accomplished in sections, otherwise, treatment of an entire lake may cause asphyxiation of fish due to algal decomposition, or toxicity due to copper or other herbicides. Because of algae importance in the aquatic food chain, endothall used in combination with other herbicides like diquat, silvex and copper sulfate to control certain aquatic plants must be carefully used so toxicity of nontarget organisms does not occur.

Descriptors :   *ECOSYSTEMS, *ALGAE, TEMPERATURE, TOXICITY, NUTRIENTS, OXYGEN, ENVIRONMENTAL PROTECTION, HERBICIDES, AERATION, AQUATIC PLANTS, EUTROPHICATION.

Subject Categories : Biology
      Water Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE