The marine biomes consist of the earth's oceans and its associated areas like the shorelines, islands, reefs and estuaries. The marine waters contain about 3.5 percent salt, mostly sodium chloride an d the organisms inhabiting these waters are profoundly adapted to these salty conditions. As landlivers we generally think of the earth as being mostly land and tend to forget that 71% of the surface of our planet is covered by oceans. In fact, often our planet is referred to as the ‘water planet!'.