The environmental significance of phytoplankton is profound, as these microscopic organisms form the foundation of aquatic food webs. They are primary producers that convert sunlight into energy through photosynthesis, generating a large portion of the oxygen in Earth's atmosphere. Phytoplankton play a crucial role in carbon cycling, absorbing carbon dioxide from the atmosphere and contributing to the regulation of global climate. Additionally, they serve as a vital food source for various marine organisms, impacting biodiversity and fisheries.