Ecology and Diversity of Zooplankton of the River Ganga at Bihar, India in Relation to Water Quality

Abstract

A study was carried out to evaluate the ecology and diversity of the zooplankton of the Ganga River at Arrah from Bihar, India from January 2018 to December 2019. Varied physical and chemical parameters supporting the zooplankton and corresponding biodiversity indices were studied. The water temperature showed inverse correlation with pH, dissolved oxygen, whereas direct relationship with total alkalinity, hardness, chloride, nitrate and sulfate. A total of 23 genera of zooplankton belonging to 6 genera of Rotifera, 5 of Protozoa, 5 of Cladocera, 4 of Copepoda and 3 of Ostracoda were identified with a density from 2 to 213 ind./L. The analysis showed that density of zooplankton declined in post-monsoon and remained maximum in summer because of the various environmental and inflow characteristics of the water body. The density of zooplankton showed direct correlation with total alkalinity, hardness and chloride of water but inverse correlation with water temperature, pH and dissolved oxygen. Shannon-Weiner index, Margalef richness index, Pielou’s evenness index, Menhninick’s index and Simpson index were won’t to assess relation of water quality with zooplankton and limnological profile of the river. The diversity indices indicated moderate to high diversity of zooplankton and moderately polluted conditions of the river.