Neritic waters, the ›rst 200  m of coastal ocean, blue waters, or oceanic waters, and the inland water bodies contribute to nearly 71% of the earth’s surface. Thus, freshwater and marine habitats form important ecosystems. These two habitats differ in their physical characteristics such as salinity, temperature, density, turbidity, nutrients, and load of pollutants. These vast variations are certainly re©ected in the associated biodiversity of microorganisms, ©ora, and fauna. These water bodies govern and regulate the global climate.