International Science Community Association Research Journal of Recent Sciences 15 2 2026 04 2 Seasonal Variations in Freshwater Phytoplankton and Zooplankton Diversity in Valsad Taluka, Gujarat, India 1 9 EN Bhandari Jatin 1 Biology Department, B.K.M. Science College, Valsad, 396001, Gujarat, India and Department of Biosciences, Veer Narmad, South Gujarat University, Surat, 395007, Gujarat, India Gohil Takhatsinh 2 Biology Department, B.K.M. Science College, Valsad, 396001, Gujarat, India > Research Paper 2025 5 3 2026 04 2 Plankton communities are an essential source of food for aquatic organisms, and any undesirable changes in the marine environment may affect plankton diversity and density. Therefore, assessing planktonic communities in freshwater ecosystems is essential because they serve as bioindicators of water quality. Hence, the present research focused on evaluating the diversity and abundance of fresh water phytoplankton and zooplankton in water bodies of Valsad Taluka, Gujarat, India. The study revealed that 77 species of phytoplankton and zooplankton were recorded, belonging to 37 families and 46 genera. Specifically, 43 phytoplankton species were recorded across 25 families and 30 genera, including 15 species of Cyanophycean, 17 of Chlorophyceae, 8 of Bacillariophyceae, and 3 of Euglenophyceae. Additionally, 34 zooplankton species were recorded across 12 families and 17 genera, including 13 Rotifera, 9 Cladocera, 8 Copepod, and 4 Ostracoda. The highest plankton diversity was observed during the monsoon season, and the lowest during the summer season. The ecological status of the water bodies in the area was categorized as moderately polluted, primarily due to municipal waste and industrial discharges. Therefore, assessing planktonic communities in freshwater bodies can be instrumental in monitoring and maintaining water quality and the health of aquatic ecosystems. Copyright@ International Science Community Association