The researchers studied zooplankton in a pond in West Bengal, India to understand their diversity and how it changes with the seasons. They found four different species of zooplankton - Daphnia, Cyclops, Cypris, and Brachionus - in the pond. The density of zooplankton varied depending on factors like temperature, pH, and oxygen levels in the water. The study showed that the pond is suitable for fish farming, but management practices are needed to maintain the zooplankton population for a healthy environment.