ARS - 2009
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/167
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Item Application of PRA tool to study fish diversity variations due to small tank renovation - A case study from Galgamuwa D.S Division(Research Symposium 2009 - Faculty of Graduate Studies, University of Kelaniya, 2009) Nishantha, K.P.L.; Najim, M.M.M.; Dangalla, N.K.Small tank renovation has been practiced with the intention of improving agricultural productivity and alleviation of rural poverty in Sri Lanka since the independence. Small tank renovation process influences changes in aquatic habitat that could have impacts on the fauna and flora in the tank systems. Small tank renovation process does not consider the possible changes that could take place on aquatic fauna and flora. This study was conducted to assess the variations that took place in bird diversity in the small tanks due to tank renovation utilizing Participatory Rural Appraisal (PRA) and questionnaire survey. Twelve small tanks from Galgamuwa D.S. Division that were renovated within last 15 years were selected using stratified random sampling technique. Randomly selected 150 farmers responded to the questionnaire survey while 400 farmers were engaged in the 12 PRA surveys conducted to cover the 12 study tanks. Results from the questionnaire and PRA surveys were used to assess the presence and abundance of fish before and after tank renovation. Tank renovation has changed the living environment of the fish and brought in some changes in the fish population. The population of carnivores has decreased due to tank renovation according to the statistical analysis. This could be due to silt deposition on gills and eggs of those species during the renovation process. The population of the omnivores has increased while fish like barbs has also increased due to reduction of the predators.Item Bird diversity variation due to small tank renovation in dry zone of Sri Lanka – A case study from Galgamuwa D.S Division(Research Symposium 2009 - Faculty of Graduate Studies, University of Kelaniya, 2009) Nishantha, K.P.L.; Najim, M.M.M.; Dangalla, N.K.Tank renovation programs implemented in Sri Lanka were intended to increase agricultural productivity but did not take into account the possible impacts on the fauna living in the tank environment. Tank renovation programs in Sri Lanka might have influenced changes in avian fauna inhabited around a tank environment. Therefore, a study was conducted to assess the variations that took place in bird diversity in and around the tanks due to tank renovation. Twelve small tanks from Galgamuwa D.S. Division were selected using stratified random sampling technique. Randomly selected 150 farmers responded to the questionnaire survey while 400 farmers were engaged in the 12 Participatory Rural Appraisal (PRA) surveys conducted to cover the 12 study tanks. Results from questionnaire and PRA surveys were used to assess the presence and abundance of birds before and after the tank renovation. Questionnaire survey identified that Cormorant species population has increased with the tank renovation. Fifty nine percent of farmers said that Cormorant (Phalacrocorax niger) could be seen rarely before the renovation but 85% of them reported that there is an increase of the Cormorant population after the renovation. Removal of tank vegetation has given them a favorable environment to catch their pray. The White-breasted Water hen (Amauronis phoenicurus) and Purple Swamp (Porphyrio porphyrio) that used the tank vegetation as the habitat and breeding site are reduced due to tank renovation. This has reduced the environment suitable for egg laying. PRA analysis identified an increase of Lesser Whistling Teal (Dendrocygna javanica) in some tanks and a decrease in some other. This study showed that tank renovation could influence the presence of different bird species due to the changes that take place in and around tank environments due to the tank renovation programs.Item Changes in amphibian and reptile species living around tank environments due to r enovation of small tanks in the dry zone of Sri Lanka – A case study from Galgamuwa D.S Division(Research Symposium 2009 - Faculty of Graduate Studies, University of Kelaniya, 2009) Nishantha, K.P.L.; Najim, M.M.M.; Dangalla, N.K.Small tank renovation programs were implemented in Sri Lanka to increase the land area under cultivation. The renovation activities could have positive and negative impacts. The environmental impacts due to tank renovation have not been studied in Sri Lanka. Therefore, a study was conducted to assess the changes that took place in amphibian and reptile species living in and around the tanks due to tank renovation. Twelve small tanks from Galgamuwa D.S. Division were selected using stratified random sampling technique. Randomly selected 150 farmers responded to the questionnaire survey while 400 farmers were engaged in the 12 Participatory Rural Appraisal (PRA) surveys conducted to cover the 12 study tanks. Results from questionnaire and PRA surveys were used to assess the presence and abundance of amphibians and reptiles before and after tank renovation. Some amphibians and reptiles lived in the tank environment have either reduced in population or disappeared after the renovation. Significance testing at 95% confidence level revealed that tortoise and water monitor populations have reduced after the tank renovation. Eighty seven percent (87%) and 72% of the farmers responded that tortoises and monitors were abundant before the tank renovation, respectively in the tank environment while only 47% and 42% agree to it, respectively after the tank renovation. According to the PRA analysis, before the tank renovation, the monitor was the second abundant but it has reduced to the sixth most abundant species after the tank renovation. Bulnawa tank was identified as the tank with the highest population of reptile species before the renovation process but after the renovation Medawachchiya and Mahagalkadawala showed higher populations. This study showed a decrease in the population of reptiles after the renovation but the amphibians do not show any variation in population