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Document Type

Research

Keywords

Lakes, Secchi disk transparency, Eutrophication, Phytoplankton

Abstract

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.

Publication Date

December 1990

Journal Title

Journal of the Iowa Academy of Science

Volume

97

Issue

4

First Page

142

Last Page

145

Copyright

© Copyright 1990 by the Iowa Academy of Science, Inc.

Language

EN

File Format

application/pdf