Browsing by Author "Dilini, R.M.A."

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Comparative study on physicochemical parameters in the rehabilitated and un-rehabilitated regions of Diyawanna lake wetland, an urban wetland in the western province of Sri Lanka
(Sri Lanka Association for Fisheries and Aquatic Resources, 2016) Dilini, R.M.A.; Wijeyaratne, M.J.S.
Diversity and abundance of phytoplankton in Diyawanna Lake, an urban wetland in the Western Province of Sri Lanka
(The Institute of Biology, Sri Lanka, 2016) Dilini, R.M.A.; Wijeyaratne, M.J.S.
Indicating the levels of eutrophication of Diyawanna Lake wetland in Sri Lanka using phytoplankton abundance
(Faculty of Science, University of Kelaniya, Sri Lanka, 2016) Dilini, R.M.A.; Wijeyaratne, M.J.S.
Diyawanna Lake is an urban wetland located in Sri Jayewardenepura Kotte. Most areas of this wetland have been rehabilitated recently by digging, restoration of banks and removing aquatic vegetation to increase its water retention capacity to reduce flooding, for recreational purposes and landing sea planes. The non-rehabilitated area in the wetland is rich in biodiversity and provides habitats for several threatened and endemic species. Present study was carried out from March to November 2015 with the objectives of determining the trophic status of the non-rehabilitated and rehabilitated areas and identifying possible indicator phytoplankton species of the trophic conditions. Sampling was carried out in March, May, July, September and November to represent the inter-monsoonal and southwest monsoonal periods in five randomly selected study sites; two in the non-rehabilitated area and three in the rehabilitated area. On each sampling, water and phytoplankton samples were collected from each site in triplicate. Phytoplankton were collected by dragging a 50μ phytoplankton net to a known distance. They were identified to the species level and Sedgwick rafter cell was used to quantitative analysis. Standard methods were used to analyze total nitrate and total phosphorous levels in water samples. Data were analyzed using two way ANOVA. Mean total phosphorous content in the two sites in the non-rehabilitated area (32 and 31 μg/L) were significantly lower (p < 0.05) than those in the rehabilitated area (52, 64 and 57 μg/L). However, these values within each area were not significantly different (p > 0.05). The mean nitrate content in non-rehabilitated area (27 μg/L and 24 μg/L) were also significantly lower (p<0.05) than those in the rehabilitated area (45, 56 and 48 μg/L). These values within each area were also not significantly different (p > 0.05). According to the total phosphorous and nitrate contents, the nonrehabilitated area of can be considered as meso-eutrophic while the rehabilitated area can be considered as eutrophic. A total of 61 species of phytoplankton were identified and none of these species were confined either to meso-eutrophic or eutrophic areas. Hence identification of any particular phytoplankton species as an indicator organisms of meso-eutrophic or eutrophic conditions was not possible. However, abundance of Microcystis aeruginosa, Scenedesmus acuminatus and Melosira islandica were significantly higher and that of Closterium moniliferum was significantly lower in the eutrophic sites than in the meso-eutrophic sites (p < 0.05). According to the present study, abundance of Microcystis aeruginosa above 110 Nos/L, Scenedesmus acuminatus above 30 Nos/L and Melosira islandica above 13 Nos/L indicate eutrophic conditions. Abundance of Closterium moniliferum above 12 Nos/L indicate meso-eutrophic conditions. However, more research using several wetlands is needed to determine the exact ranges of abundance for demarcating the trophic conditions.
Role of the coastal community and the government in sustainable utilization and management of coastal resources in Unawatuna, Sri Lanka
(Faculty of Science, University of Kelaniya, Sri Lanka, 2016) Moragoda, M.K.N.P.; Ranasinghe, O.R.; Dikkumbura, H.K.U.S.; Kalaotuwawe, K.M.B.P.; Karunapala, H.M.B.N.; Dilini, R.M.A.; Gamanayake, B.G.N.N.; Kuruppuarachchi, H.D.; Chandrasekara, W.U.
Unawatuna is a coastal town in southern Sri Lanka, and its safe sandy beach is popular among local and overseas tourists. Since this beach generates a considerable amount of income through tourism, it is of paramount importance to manage and sustainably utilize its coastal resources in order to improve tourism and quality of life of the local community. With this view, a field survey was carried out on this location in October 2014 to assess the role of the local coastal community and the local government authorities in sustainable utilization, management and governance of coastal resources in Unawatuna beach. In this survey, a questionnaire based survey on the local community (n = 20) as well as on randomly selected individuals (n = 15) on the beach was carried out by holding face-to-face interviews. In addition, a questionnaire survey on the chief executive officers of the local authorities in the area viz. Area Engineer’s office of Coast Conservation Department (CCD) in Unawatuna, Southern Provincial Office of Central Environmental Authority (CEA), Habaraduwa Police Station and Habaraduwa Pradeshiya Sabhawa was also carried out by holding face-to-face interviews. Data obtained from both components of the survey were subjected to analyses and a SWOT analysis was carried out. The major strengths identified by the analysis included the presence of a variety of natural resources and cultural attractions on the beach. The educational level of people in the beach surroundings was high where 58.8% had above O/L educational qualifications. Further, the beach is cleaned daily by organized groups in the community (58.82%) so that the cleanliness of the beach was high (76.47%). The local community also received a fairly high income from tourism (73.33%). The CCD and CEA are strongly involved in coastal erosion prevention programmes, conducting awareness programs for the stakeholders on the beach area, implement policies, plans, projects and strategies to conserve the coastal resources in the area. The tourist police unit of Habaraduwa police station maintains law and order in the area and take strict legal actions against illicit drug and liquor trade and use. Further, the Habaraduwa Pradeshiya Sabhawa carried out public utility services including daily removal of garbage from the surrounding area. The major weaknesses identified were lack of awareness (15.21%) and lack of commitment (19.56%) of stakeholders on coastal resources management practices and difficulties in implementing laws and regulations (6.52%). There are opportunities for improvement of recreational, beach protection and development activities, and involving unemployed persons of the local community (23.53%) in tourism. The major threats were beach pollution by sewage and solid waste (25%), interferences by external parties such as large scale hotel owners and politicians (20.83%), high government taxes (37.5%), illegal constructions on the beach façade (20.83%) and coastal erosion due to unplanned construction of a break water. The present study highlights the involvement of a co-management strategy in Unawatuna beach area on the governess and management of coastal resources with positive inputs from both the local government authorities and the stakeholder community. Reinforcing and strengthening the existing co-management strategy is recommended for the proper governess, management and sustainable utilization of coastal resources in the Unawatuna coastline.