Marine microorganism to the secondary productivity and carbon sink of the world oceans than any other group of organisms. Marine microorganism Marine microorganisms are defined by their habitat as the microorganisms living in a marine environment, that is, in the saltwater of a sea or ocean or the brackish water of a coastal estuary. A microorganism (or microbe) is any microscopic living organism, that is, any life form too small for the naked human eye to see, needing a microscope. Microorganisms are very diverse. They can be single-celled or multicellular and include all bacteria and archaea and most protozoa, as well as
Marine microorganism the Paleozoic era (390 million years ago). Of eukaryotic groups, the protists are most commonly unicellular and microscopic. This is a highly diverse group of organisms that are not easy to classify. Several algae species are multicellular protists, and there are marine slime molds have unique life cycles that involve switching between unicellular, colonial, and multicellular forms. The number of species of protists is unknown, and we may have identified only a small portion. Studies from 2001-2004 have shown that a high degree of protist diversity exists in oceans, deep sea-vents, river sediment and an acidic river, which suggests that