Diatom distribution and its relationship with water quality in the Mahi River Basin

Abstract

This study was conducted to determine the diatom distribution pattern in a changing physicochemical environment in the Mahi River Basin, western India. Results showed the dominance of bottom-dwelling pennate forms of diatoms over floating centric forms of surface waters, which otherwise prefer pond water, suggesting control of physicochemical conditions, which further is a function of local lithology. The lower reaches of the Mahi Basin, where mixing through industrial effluents is significant, show higher frequency of Cymbella spp. and Synedra capitata suggesting slightly increased eutrophic conditions. This can also be used effectively as a tool for monitoring ecological/environmental conditions. The CCA test in most cases confirms the direct relation of physico-chemical components with the diatom population. The contemporary diatom assemblages of different water bodies of the upper and lower Mahi River Basin provide recent analog, which can be further applied on much older successions for precise palaeoenvironmental and palaeoclimatic interpretation. However, this would require a more detailed study.