Lakes, Secchi disk transparency, Eutrophication, Phytoplankton
Secchi disk transparencies, chlorophyll a concentrations, and total phosphorus concentrations were studied in Lake West Okoboji, Iowa, in the summers of 1971-7 3 and 1987-89. The average summer Secchi disk transparencies varied from a low of 2.5 to a high of 5.5 m during the study. The variations in the transparency of lake West Okoboji from year to year seem to be related to climatic factors such as the amounts of spring precipitation in the watershed and probably reflect changes in the annual inputs of plant nutrients. There is some indication that climatic conditions that cause the period of deep mixing to extend into the early summer lead to a greater Secchi disk transparency, but more data are needed to confirm this hypothesis. Other than these fluctuations related to climatic variables, there is no indication of any systematic changes in water quality in the period from the early 1970s to the late 1980s.
Journal of the Iowa Academy of Science
© Copyright 1990 by the Iowa Academy of Science, Inc.
Bachmann, Roger W.
"Climatic Influences on Annual Variations in Water Transparency in Lake West Okoboji,"
The Journal of the Iowa Academy of Science: JIAS: Vol. 97:
, Article 10.
Available at: http://scholarworks.uni.edu/jias/vol97/iss4/10