Organic matter of sediments from the retting and nonretting areas of Kadinamkulam estuary, southwest coast of India

Abstract

Organic matter of sediments of two retting and two nonretting areas were evaluated over a period of one year. Organic carbon and organic matter showed enrichment in the sediments of retting sites (ranging from 19 to 137.9 mg/g and 32.7 to 237.7 mg/g, respectively) as compared to nonretting zones (ranging from 3.1 to 49 mg/g and 5.3 to 84.4 mg/g, respectively). The energy content of the sediments from the retting sites were also high (699.78 to 5134.3 J/g dry weight) as compared to sediments from nonretting sites (114.5 to 1823 J/g). Effect of monsoon was found to be significant. The pectinolytic activity of microorganisms during the retting process liberates large amounts of pectin, phenol, tannin, lignin into the water body. The accumulation of such organic compounds during retting process has lead to the high percentage of organic carbon in the retting zones. Sand, silt and clay were low at the retting and nonretting zones particularly during the monsoon periods.