Abstract

Mangrove forests are among the world’s most productive ecosystems (Kathiresan and Bingham, 2001).This resource has faced depletion and degradation during the last few decades in Sri Lanka. This paper attempts to find the causative factors of depletion and degradation of mangroves in southern Sri Lanka during the twenty-three-year period from 1994 to 2017 and attempts to find the solutions to minimize it. Garaduwa, Mahamodara and Galdoowa lagoon areas and Polwatumodara river mouth area, are included in the study. The study used mixed-methods design forbetter understanding of the research problem.A questionnaire, focus group discussion (FGDs), observations and secondary data was used for this study. Google Earth maps and aerial photographs were used to estimate the mangrove resource use of the four selected mangrove areas.Approximately, 10 percent of the total householders of the study area(384) were consulted to collect primary data by using random sampling.Both quantitative and qualitative methods were used to analyse the collected data, such as GIS mapping and analysis, standard deviation and percentage. The results highlight that the main methods of depletion anddegradation of mangrove are used for firewood, settlements, development activities and conversion for agriculture.Mainly seven species were used for firewood (more than 50% of households).Socio-economic factors such as income, employment, ethnicity, distance to mangrove land,residential area, usage of gas for cooking, education level,and age (mangrove use of fuel) affected the higher use of mangrove resource as a fuel. A large number of householders who responded are still dependent on the wood stove for cooking.The results further reveal that many people collect fuel wood for their daily needs in every day. More than 44% of households do not have gas cookers and as a result, they used mangrove fuel wood as an alternate method for their cooking. Research is needed to reduce the threats and to understand mangrove species better, and to direct conservation initiatives.Alternative resources and methods to avoid the mangrove resource degradation has to be searched.

Keywords: Aerial photographs, Depletion, Fire wood, Google Earth, Mangrove