An attempt to recover economic losses from decadal changes in two lagoon systems of Sri Lanka through a newly patented mangrove product

Kahandamodara and Kalametiya are two estuarine lagoons located within about 12 km distance along the Southern coast of Sri Lanka. According to a socio-economic survey, both lagoons have been moderately to high saline water bodies and the latter was an important center of prawn fishery until the late 1960s. Two irrigation projects upstream (Udawalawe irrigation scheme and Muruthawela Wewa), which came into operation in 1967 and 1968 respectively, increased freshwater inflows to these two lagoons and altered flora, fauna, and water quality, with a decline of lagoon fishery as a result. At the same time, the increase in freshwater favorised the Mangrove Apple Sonneratia caseolaris to expand spontaneously. Following many hectares of vegetation increase of this species, our study focused on recovering the economic loss of fisheries decline by using new ethnobotanic information on this species. We found that the pulp of the fruit of the Mangrove Apple is tasty and can be used to prepare a fruit drink. However, it has not been commercialised, or even practiced widely at homes, due to the fact that numerous small seeds in the fruit release certain phenolic compounds when damaged, giving a bad colour and an astringent taste to the pulp. We developed a method to get the fruit pulp from the Mangrove Apple minimising the addition of phenolic compounds. This fruit pulp was then used to produce ice cream and fruit drinks, and the whole procedure has been patented in Sri Lanka for the favour of the local people. Apparently this is a novel mangrove product reported for the first time in mangrove ethnobotany. In addition, analysis of the fruit pulp of the S. caseolaris for nutritional composition revealed that it is very rich in phosphorus and dietary fiber, indicating that these new products may have an even higher potential as a supplementary food. Its use as a health food and as a commercialised eco-product is expected to bring new gains in spite of the former ecosystem and fishery decrease. It is however not known to which extent these novel ethnobiological/socio-economical uses outbalance functions lost by ecosystem degradation.