The composition of sea water in the marine environment with respect to nitrogen and phosphorus is known to be regulated in a large measure by the growth and activity of organisms. The cycle of synthesis and decomposition involves the absorption of these nutrients by growing plants and the release upon decay of their tissues. The first phase takes place within the photosynthetic zone, and the second phase largely in the “zone of decay” below this productive zone. Oxidative processes during the decomposition phase entail the utilization of oxygen which, as a by-product of the synthesis phase, is conditioned by the oxygen exchange between the atmosphere and the surface layer of water with which it is in contact. In the underlying zone of decay the amounts of dissolved oxygen and the nutrient salts can be accounted for by the mineralization of organic matter and the addition of new supplies of these materials due to water circulation.
View the PDF Article