Marine organisms refer to all living beings that inhabit the marine environment, which includes bodies of water such as oceans, seas and other smaller water bodies. These organisms include a wide range of species from microscopic plankton to large mammals like whales, fishes, invertebrates, algae, seaweed, etc. They are adapted to survive in the salty environment with varying degrees of salt tolerance and have developed unique physiological, morphological and behavioral adaptations that enable them to thrive in their specific marine habitats.