marine anoxic zone ORCID:0000-0002-4366-3088 SWEETRealm:DeadZone Marine anoxic zones are areas of marine water that are depleted of dissolved oxygen. This condition is generally found in areas that have restricted water exchange. In most cases, oxygen is prevented from reaching the deeper levels by a physical barrier (sill) as well as by a pronounced density stratification. Anoxic conditions will occur if the rate of oxidation of organic matter by bacteria is greater than the supply of dissolved oxygen. dead zone 2010-03-16T12:16:11Z envoPolar marine environmental zone