Evaluation of the Trophic State and Potential Occurrence of Musty Odor in Tropical Lakes

Abstract

Two products of cyanobacteria, 2-methylisoborneol (MIB) and geosmin, are responsible for the musty odor of some lakes in Japan and the United States. I confirmed the correlation between the intensity of the musty odor and the population of certain cyanobacterium by analysis of the results of field surveys of Lake Kasumigaura and Lake Kouzogawa, Japan. My objectives were to identify how natural conditions such as temperature, nutrients including organic and inorganic substances, pH, and light influenced the production of musty odor and to predict the occurrence of musty odor by correlation analysis between the causative cyanobacteria and environmental factors (temperature, pH, COD, TN and TP) with the aim of applying this information in Vietnam. Among the cyanobacteria, Phormidium tenue, Anabaena, and Oscillatoria were the major producers of MIB during their proliferation periods. The seasonal occurrence of the musty odor was a result of influences of temperature on the activities of musty odor producers. I discuss here the relationship between environmental factors and musty odor production associated with aquatic microorganisms with the data from lake Kasumigaura and Kouzogawa. I also analyzed data on the environmental conditions (water quality and temperature) and presence of microorganisms in the inland waterbodies of Vietnam in order to predict the potential occurrence of musty odor in the lakes of northern Vietnam.