George A. Irwin Elmer G. Pearson 1972 <p>Big Bear Lake exhibited seasonal changes in physical, chemical, and biological variables from June 1968 to June 1969.</p><p>Dissolved-oxygen concentrations were depressed during the summer resulting in anaerobic conditions near the bottom of the lake. Water temperature decreased with depth in spring and summer, although classical thermal stratification was not observed. The nutrient standing crop was sufficient to maintain two distinct seasonal phytoplankton blooms. There were phytoplankton growth periods during the winter of 1968 and the summer of 1969, but the maximum populations that were observed were not excessive.</p><p>During the study Big Bear Lake exhibited periods of biochemical stress symptomatic of organically enriched lakes; however, no attempt was made to determine the magnitude or rate of the eutrophicational processes occurring in the lake.</p> application/pdf 10.3133/ofr72295 en U.S. Geological Survey Limnological studies of Big Bear Lake, California reports