Backwaters near Kumarakom

Kerala, situated in the south-western part of the Indian peninsula, is a narrow strip of land between the Western Ghats and the Arabian Sea with a total land area of 38,863 sq. km. There are three major lakes in the southern part of the state, the Vembanad Kayal, the Ashtamudi Kayal, and the Chetuva Kayal. They have access to the Arabian Sea through bar mouths and are, therefore, also called the "backwaters". These backwaters, stretching irregularly along the coastline, support a wealth of marine and freshwater life due to tidal incursion and excursion containing rich nutrients from the Arabian Sea. They have ecological significance as they connect the river system with the sea, act as ecological buffer zone, and support excellent fish fauna as well as other renewable aquatic resource.

These backwaters have also been subjected to excessive human intervention. The coir production, through retting of coconut husk, is a traditional occupation and a major economic activity in the area. More than 70% of coir produced in India comes from Kerala, which annually produces about 120,000 tonnes of the fibre. This industry employs approximately 3,83,000 people, about 84% of whom are women. Coconut husk is transported from plantations to coastal area for retting. The process involves immersion of husk in shallow backwaters for 6 to 9 months. After that, decayed material is removed from the fibre by pounding. Bacteria act on the organic matter during the process and release putrefied and toxic materials into the environment. Hydrogen sulphide, methane and phenol compounds are released into water which kill fauna and flora. Several stretches of backwaters' shore have become unusable due to this activity. A recent study at Kunnur showed that the pH value of water in retting area is significantly lower than that in a non-retting zone. The concentration of phosphates, nitrates and hydrogen sulphide is higher. The presence of sulphide imparts a greyish black colour to water, restricting light penetration and inhibiting photosynthesis. It damages the fragile ecosystem.