Plankton Diversity and Water Quality in Azhagankulam Pond of Tirunelveli, Tamilnadu, India

The present study investigates the diversity and abundance of plankton, alongside the physicochemical parameters of Azhagankulam Pond in Kurichikulam near Sankar Nagar, Tirunelveli district, India. Zooplankton feed on phytoplankton, helping to regulate algal populations and preventing uncontrolled growth. They respond quickly to environmental changes, making them valuable bioindicators of water quality, including factors like pH, dissolved oxygen, and nutrient levels. Their abundance and composition vary with organic pollution and geographical location. Water sample was collected by net made of nylon bolt mesh. The collected sample was filtered separately using filtering stand with different mesh sizes of 100 micron and 160 micron. Live zooplanktons including Rotifers were kept in clean glass slides and covered with cover slip for photography. Photographs were taken in the microscope. Statistical analyses were carried out by using multivariate statistical tools. A total of 24 species of zooplankton were identified, including Rotifers, Copepods, Cladocerans, Ostracods, Blue-Green Algae, Green Algae, Diatoms, and Protozoans. Among these, Brachionus caudatus (Rotifers), Calanus species (Copepods), Daphnia (Cladocerans), and Spirulina (Phytoplankton) were found to be dominant across the study period. The highest plankton abundance was recorded in March (21.99 standard deviation), with species numbers increasing progressively from December. Plankton populations are influenced by physicochemical factors such as temperature, salinity, and pollution. The study recorded eutrophic conditions, particularly in February and March, with Brachionus caudatus and Spirulina dominance, indicating high nutrient levels. The seasonal variations in plankton composition and diversity indices demonstrate the direct impact of environmental factors and nutrient dynamics on freshwater biodiversity. Long-term monitoring and sustainable management practices are essential to maintaining the ecological stability of Azhagankulam Pond.