The study of the aquatic habitats and organisms therein is known as limnology (for freshwater systems) and marine biology (for saltwater environments). Limnology focuses on the interactions within lakes, rivers, and wetlands, including their ecosystems, chemistry, and organisms, while marine biology explores oceanic ecosystems, organisms, and their relationships. Both disciplines study the biodiversity and ecological functions of these environments, addressing critical issues such as pollution, conservation, and the impacts of climate change on aquatic ecosystems.