Oxygen depletion water

Ingall, E. D. and Jahnke, R. A. (1994). Evidence for enhanced phosphorus regeneration from marine sediments overlain by oxygen depleted waters. Geochim. Cosmochim. Acta 58, 2571-2575. 

N2 production in the oxygen depleted waters over the shelf, canonical denitrification was not detectable. 

Nitrite-N (N02 ) has an intermediate redox position between that of NH4 and N03, thus N02 often accumulates in selected depth strata when active N transformations are occurring (Rakestraw, 1936 Vaccaro and Ryther, 1960). In the global ocean, two such zones have been identified and studied (Fig. 16.11) (1) the primary N02 maximum (PNM) zone that is usually located near the base of the euphotic zone worldwide and (2) the secondary N02 maximum (SNM) zone that is most prominent in oxygen depleted waters (Codispoti and Richards, 1976 Fiadeiro and Strickland, 1968). 

The magnitude of this fraction (Table 3.2), which has important implications concerning the bioavailability, transport and fate of these constituents (Balls, 1989 Pankow MacKenzie, 1991 Webster Ridgway, 1994) varies from more than 90% for Cd and Cs in sea water and oxygen depleted waters of the Clyde, to less than 5% for 2,3,7,8-TCDD in the Humber Estuary and the low salinity zone of the Clyde. 

Bivalves such as oysters and clams have the important role to decrease the suspended solid. So, once they decrease, transparency will fall and seaweed will become extinct. Furthermore, when ph ffoplankton is decomposed on the seabed, nutrients will be emitted to the sea water again and a further increase of phytoplankton will be caused. Thus, oxygen-depleted water causes remarkable damage to the ecosystem inside the bay. 

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