Impact of coconut husk retting on the physical and chemical characteristics of the water samples of retting and non-retting zone of Paravur backwater

The Kerala backwaters well known for their high productivity and fisheries are threatened by the fast expanding coir industry. The coir fibre is extracted by a process called retting. Paravur backwater, the largest brackish water system in Kerala accommodate many coconut husk retting grounds, which is considered as one of the important sources of pollution in that backwater. Retting brought about by the pectinolytic activity of bacteria and fungi, liberates large quantities of organic substances including pectin, pectosan, fat, tannin and also toxic polyphenols into the ambient water. The present investigation was carried out to analyse the various hydrographical parameters of the retting and non-retting zone. The surface and bottom water samples were collected from both the retting and non-retting zones during the (pre and post monsoon) period. The water samples were used for estimation of parameters such as temperature, transparency, pH, turbidity, total hardness, chloride, dissolved oxygen, dissolved CO₂, total alkalinity and nutrients such as phosphate, nitrate, sulphate and iron. The results indicated that retting process produced high degree of pollution.