The term used for a scientist who studies marine life is a marine biologist. Marine biologists examine various aspects of ocean ecosystems, including the behavior, physiology, and interactions of marine organisms, as well as their roles in the environment. Their work can involve field studies, laboratory research, and analysis of data on subjects ranging from microorganisms to large marine mammals. Marine biologists contribute vital information regarding biodiversity, conservation, and the impacts of human activity on aquatic habitats. Their research is instrumental in informing policies aimed at protecting marine ecosystems and ensuring sustainable use of ocean resources.