Comparison of seasonal and diurnal patterns of some physico‐chemical parameters of the open and closed parts of Loktak Lake, Manipur, India

A comparative study of the periodic and aperiodic variations of some physico‐chemical parameters of the open and closed parts of the Loktak Lake, Manipur, India, was carried out for a period of three years from 1976–78 to investigate the effects, if any, of human activities on these variations. The closed part of the lake, used for controlled fishing was well protected, whereas the open part was subjected to considerable human activities. The variation in the physico chemical parameters in the open lake were different from those of the closed lake in that (a) there was distinct seasonal variation in DO which was not evident in the closed lake and (b) there was direct relationship between diurnal variation of CO₂ and pH instead of an indirect relationship in the closed lake. The variation in pH, electrical conductivity, bicarbonate, free carbon dioxide and chloride between 1976–78 had a similar pattern in the two parts of the lake.