Jellyfish jellyfish, because jellyfish feed on plankton, which includes fish eggs and larvae. Jellyfish form a component of jelly-falls, events where gelatinous zooplankton fall to the seafloor, providing food for the benthic organisms there. In temperate and subpolar regions, jelly-falls usually follow immediately after a bloom. Most jellyfish are marine animals, although a few hydromedusae inhabit freshwater. The best known freshwater example is the cosmopolitan hydrozoan jellyfish, "Craspedacusta sowerbii". It is less than an inch (2.5 cm) in diameter, colorless and does not sting. Some jellyfish populations have become restricted to coastal saltwater lakes, such as Jellyfish Lake in Palau. Jellyfish
Marine biology (whales) in length. Marine ecology is the study of how marine organisms interact with each other and the environment. Marine life is a vast resource, providing food, medicine, and raw materials, in addition to helping to support recreation and tourism all over the world. At a fundamental level, marine life helps determine the very nature of our planet. Marine organisms contribute significantly to the oxygen cycle, and are involved in the regulation of the Earth's climate. Shorelines are in part shaped and protected by marine life, and some marine organisms even help create new land. Many species are economically important