Seasonal Variation, Diversity, and Composition of Planktons in the Ganga River

Abstract

Plankton are important components of aquatic ecosystems because they contribute to primary production, which sustains fisheries and other ecosystem functions. The study was carried out over a one-year period at three Ganga River sites: Haridwar (Bhadrabad) site A1, Bijnor (Balawali) site A2, and Muzaffarnagar (Bairaj Ganga bridge) site. Bacillariphyceae made almost 65% of the phytoplankton at location A1 14% Chlorophyceae and 14% Cynophyceae. The zooplankton consisted of Protozoa (80%) and Cladocera (20%), with Ulvophyceae accounting for 7%. At location A2, the phytoplankton composition was Bacillariphyceae (79%) and Chlorophyceae (7%). ˃ Cynophyceae (7%). Ulvophyceae (7%), and zooplankton were Protozoa (80%), Rotifera (20%). At location A3, the phytoplankton mix shifted to Bacillariphyceae (70%). ˃ Chlorophyceae (18%) ˃ Cynophyceae (12%) and Protozoa (60%) Rotifera accounts for 40%. The Simpson diversity index (D) value for phytoplankton is 0.58, whereas for zooplankton, the value is 0.53. The mean plankton density at locations A1, A2, and A3 was 2059, 2959, and 3304 individuals per liter, respectively. Only dissolved oxygen in physicochemical characteristics correlated positively with plankton density; all other metrics correlated negatively.