Degradation of Pichavaram mangroves started in 1930s, when the British government introduced clear-felling system of management. In this system, mangrove forests were clear-felled in small coupes of about 15 to 20 hectare every year until 1970s.

Clear-felling of mangrove trees exposed the mangrove wetlands to the sun. The soil contains nearly 80 per cent water, which evaporated . Evaporation of water caused depression in soil . Saline water entered these depressions and became stagnant.

Again, evaporation of the stagnant water over a period of time increased soil salinity to a level in which a mangrove cannot survive.

The M.S.Swaminathan Research Foundation developed and demonstrated simple and cost effective method to restore degraded areas of Pichavaram mangroves. It was done as research project in small area of about 10 hectares.

Later, the MSSRF extended the restoration and conservation of mangrove wetlands of Pichavaram in partnership with the Tamil Nadu Forest Department and the local community. Now all the degraded areas – about 800 ha in total – have been restored.

V. Selvam, director, Coastal Systems Research, M.S. Swaminathan Research Foundation, told The Hindu , “The MSSRF identified the above causes for degradation and developed a canal system to avoid stagnation of saline water in the clear-felled areas. This canal system allowed water to freely flow in and out of the degraded areas and reduced soil salinity. After this, mangrove plants were planted. This is a restoration method the MSSRF developed and demonstrated successfully.

“Increasing economic stake in mangrove conservation is necessary. In this respect, the MSSRF developed an integrated mangrove fishery farming system, in which 70 per cent space is allotted for fish culture and 30 per cent for mangrove plantation. In this model, over a period of five years good mangrove forest would develop even as fish culture helps to generate a revenue of about Rs. 20,000 to Rs. 30,000 a year,” Mr. Selvam said.

The United Nations Framework Convention on Climate Change (UNFCCC) has accepted this as one of the models to increase the capacity of local community against the rise in sea level and has provided funds to demonstrate this Integrated Mangrove Fishery Farming System on 50 hectare in one place in Andhra Pradesh, he added.