Studies on Organic Carbon, Nitrogen and Phosphorus in Sediments of the Cochin Backwater

Distributions, seasonal changes and ratios of organic carbon, total phosphorus and total nitrogen have been studied in sediments collected from 4 stations in Cochin backwater. The observed high organic carbon contents up to 3.84% in the sediments may be due to river discharge bringing in a large amount of water humus and also to high organic production of the overlying water. Total phosphorus distributions also show higher concentrations (0.9-2.4 mg/g), which may be attributed to the influence of domestic waste. Nitrogen/phosphorus ratios indicate that the major portion of phosphorus in the sediments is of abiogenic origin. Correlations between organic carbon and total phosphorus are also discussed.