Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Wildlife Management


Physical, chemical, and biological aspects of 45 lakes in South Dakota were studied from July 1965 to July 1967. Maximum water temperature at the surface reached 28 C. Most of the lakes studied exhibited continuous circulation except when ice covered. Thermocline formation was observed in six of the lakes. Light transmission was influenced by turbidity, and varied greatly within individual lakes and among lakes. Dissolved oxygen concentrations ranged from near saturation to less than the recommended minimum for fish life. All likes studied were basic ranging from a pH of 7.1 to 11.3. Specific conductance of lakes occupying open basins was lowest in the un-glaciated area west of the Missouri River (70-590 micromhos at 25 C) and highest in Mankato drift of the Wisconsin ice age (330-1260 micromhos at 25 C). concentrations of major anions and cations tended to follow patterns which were associated with major physical division of the state or various drift types of the Wisconsin ice age. Trace elements were found in most lakes studied. Those lakes which developed dense summer blooms of phytoplankton were usually dominated by the blue-green algae Aphanizomenon or Microcystis. The maximum concentration of Chlorophyll a observed was 19.1 mg/l. Chlorophyll concentrations were generally higher in lakes east of the Missouri River.

Library of Congress Subject Headings

Lakes -- South Dakota
Limnology -- South Dakota


Includes bibliographical references (pages 83-86)



Number of Pages



South Dakota State University


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