oceanic pelagic zone biome oceanic sea surface microlayer biome 2010-03-15T11:21:03Z ENVO ENVO:01000034 ORCID:0000-0002-4366-3088 The oceanic sea surface microlayer (SML) biome comprises the top 1000 micrometers of the marine surface waters occurring offshore, away from a continental shelf. It is the boundary layer where all exchange occurs between the atmosphere and the ocean. The chemical, physical, and biological properties of the SML differ greatly from the sub-surface water just a few centimeters beneath.