Abstract

Zooplankton communities play a vital role in aquatic ecosystems, serving as indicators of water quality and primary consumers in the food web. Environmental conditions and different nutrient concentrations affect their diversity and abundance. This research investigates the seasonal abundance of four major zooplankton groups including Protozoa, Rotifera, Cladocera, and Copepoda about key water quality parameters across six seasons: summer, spring, rainy, late autumn, autumn, and winter. Zooplankton samples were collected monthly over one year, and their abundance was analyzed alongside water temperature, pH, dissolved oxygen, transparency, and nutrient levels. The results show that the total zooplankton density ranged from 1,250 to 4,870 individuals/L, with the highest abundance observed in summer (4,870 ind./L) and the lowest in winter (1,250 ind./L). Protozoa dominated in the rainy season (42.3%), while Rotifera had the highest percentage in summer (38.6%). Cladocera showed peak abundance in autumn (22.5%), whereas Copepoda was most abundant in late autumn (19.2%). Higher temperatures and nutrient levels in summer coincided with increase in zooplankton abundance, whereas colder temperatures in winter led to a decline in population density. The findings highlight the zooplankton communities’ dynamic nature and their relationship with environmental conditions, emphasizing the need for continuous monitoring to support freshwater ecosystem management.