Role of Phytoplankton in Comprehending the Vulnerabilities Imposed due to Gangasagar Festival

Abstract

Sagar Island, one of the densely inhabited island of Sundarbans deltaic complexes is experiencing severe population pressure in the recent past. Its population count has exceeded over 2.12 lakhs. During Gangasagar festival, another lot of pilgrims come over with an intention to take a holy dip at the Gangotri confluence. This mass gathering elevates the pollution levels. It depicts a cyclic usage of water having religious prototype, consisting of bathing at particular sites resulting in drastic alteration of the biogeochemical symmetry of the aquatic ecosystem. Phytoplankton being the primary producers occupies the base level of aquatic food webs. They have a potent role in indicating water quality. Even minute alterations in phytoplankton community can affect the world climate. Therefore, for maintaining a balanced ecosystem, their respective levels should be kept on a count. Phytoplankton biomass was maximum during post-Gangasagar phase and minimum during pre-Gangasagar. In terms of abundance, Bacillariophyceae exhibited prominence and Dinoflagellates diversified after Gangasagar festival implying high pollution levels of Sagar. The largest influence on phytoplankton plethora is nutrient scarcity. Also, blooms of dinoflagellates due to nutrient variability have large ecosystem impacts on water quality. These changes in the primary producers eventually affect primary production and biogeochemical cycle.