The benthic zone is the lowest layer of a body of water, such as an ocean, lake, or river. It includes the sediment surface and sub-surface layers, where organisms live on or in the sediment. This zone is home to various species, including benthic invertebrates, crustaceans, and benthic fish, which play essential roles in the ecosystem. In the benthic zone, conditions can vary significantly based on depth and location. Factors like light availability, temperature, and nutrient levels influence the types of organisms that thrive there. The benthic zone is crucial for nutrient cycling and serves as a habitat for many aquatic species.