Oxygene, phosphate et gaz carbonique total en Mer de Corail

Abstract

In the Coral Sea, the correlations between the apparent oxygen utilization and the inorganic phosphate concentration on one side, the total carbon dioxide concentration on the other side, are significant. The regression curve of total carbon dioxide on apparent oxygen utilization is a straight line; the ratio atom by atom A.O.U./C. is close to $\text{1}\text{1}$ which is half of the theoretical value. The regression of inorganic phosphate on A.O.U. does not seem to be best represented by a straight line and the ratio A.O.U./P. which is smaller than $\text{180}\text{1}$ varies with depth. A possible explanation of this anomaly is found in a slight difference between the composition of the oxidizable organic matter and that of the basic molecule of carbohydrate which is considered to be the first step in the photosynthetic process; for instance the percentage of hydrogen could be smaller and the phosphorus concentration at 1000 m triple of that near the surface. Further computations show that the equatorial waters of the Pacific do not contain any preformed phosphate and that the organic matter which is synthesized in the eastern Pacific must be rich in nitrogen.