The Temperature Cycle in the Okoboji Lakes

For the past thirty years members of the staff of the Iowa Lakeside Laboratory have been interested in the flora and fauna of the Okoboji region. For a somewhat shorter period of time, whenever equipment has been available, studies have been made of the physical and chemical characteristics of the Okoboji Lakes in the hope of obtaining a better understanding of the environmental factors which affect the biological productivity of these bodies of water. The factors which determine the geographical distribution of any given species and the numbers of individuals of that species which are present at any given time are extremely numerous. The geology and climate of a given region determine the chemical and physical characteristics of the body of water which in turn determine the limits of biological existence