The habitats studied in marine biology include everything from the tiny layers of surface water in which organisms and abiotic items may be trapped in surface tension between the ocean and atmosphere, to the depths of the oceanic trenches, sometimes 10,000 meters or more beneath the surface of the ocean.
Habitater undersøgt af marinbiologi omfatter alt fra tynde vandoverflader hvor organismer og abiotiske emner kan blive fanget i overfladespænding mellem havet og atmosfæren, til dybderne af oceangravene, nogle er 10.000 meter eller mere under havoverfladen.