Improved Detection of Oxygen Consumption, Nitrate Reduction, and CO(2) Evolution in the Deep-Sea,

Abstract : Using maps of respiratory electron transport activity in the coastal upwelling areas off Oregon, southern California, and northwest Africa, the author has been able to distinguish rising freshly upwelled waters from the waters of a relaxed upwelling event. Using measurements of ETS activity deep under the Peru Current, and oxygen and current measurements in the basins of the southeastern Pacific Ocean the author has calculated that the 2000 m water has taken 685 years to move from its origins at 70 degs S latitude to the Peru Basin. Using ETS activity measurements from the oxygen minimum zone of the western Mediterranean and the Alboran Sea, the author has shown that under the Alboran gyre to the east of the Straits of Gibraltar there lies a bolus of water that exhibits enhanced metabolic activity. Measurements of pH, inorganic nutrient salts, and particulate ATP, carbon and nitrogen all confirm the presence of this metabolically active body of water. Collectively, this data is the best and clearest evidence for the biochemical role in the formation of oceanic oxygen minimum zones. The author participated in one cruise to the Alboran Sea during he measured the ETS activity and particulate carbon and nitrogen. The results provided additional evidence for the biochemical formation of the oxygen minimum zone in the western Alboran and supported previous conclusions. Laboratory experiments were conducted to detect and preserve ETS activity.