Browsing by Author "Pushpalatha, K.B.C."
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Item Culture-based fisheries in non-perennial reservoirs in Sri Lanka: production and relative performance of stocked species(Fisheries Management and Ecology, 2005) Wijenayake, W.M.H.K.; Jayasinghe, U.A.D.; Amarasinghe, U.S.; Athula, J.A.; Pushpalatha, K.B.C.; de Silva, S.S.In Sri Lanka, there is a great potential for the development of culture-based fisheries because of the availability of around 12 000 non-perennial reservoirs in the dry zone (<187 cm annual rainfall) of the island. These reservoirs fill during the north-east monsoonal period in October to December and almost completely dry up during August to October. As these non-perennial reservoirs are highly productive, hatchery-reared fish fingerlings can be stocked to develop culture-based fisheries during the water retention period of 7?9 months. The present study was conducted in 32 non-perennial reservoirs in five administrative districts in Sri Lanka. These reservoirs were stocked with fingerlings of Indian (catla Catla catla Hamilton and rohu Labeo rohita Hamilton) and Chinese (bighead carp Aristichthys nobilis Richardson) major carps, common carp Cyprinus carpio L., genetically improved farmed tilapia (GIFT) strain of Nile tilapia, Oreochromis niloticus (L.) and post-larvae of giant freshwater prawn, Macrobrachium rosenbergii De Man, at three different species combinations and overall stocking densities (SD) ranging from 218 to 3902 fingerlings ha?1, during the 2002?2003 culture cycle. Of the 32 reservoirs stocked, reliable data on harvest were obtained from 25 reservoirs. Fish yield ranged from 53 to 1801 kg ha?1 and the yields of non-perennial reservoirs in southern region were significantly (P < 0.05) higher than those in the northern region. Naturally-recruited snakehead species contributed the catches in northern reservoirs. Fish yield was curvilinearly related to reservoir area (P < 0.05), and a negative second order relationship was evident between SD and yield (P < 0.05). Chlorophyll-a and fish yield exhibited a positive second order relationship (P < 0.01). Bighead carp yield impacted positively on the total yield (P < 0.05), whereas snakehead yield impact was negative. Bighead carp, common carp and rohu appear suitable for poly-culture in non-perennial reservoirs. GIFT strain O. niloticus had the lowest specific growth rate among stocked species and freshwater prawn had a low return.Item Gillnet selectivity of Ompok bimaculatus (Siluridae) and Puntius dorsalis (Cyprinidae) in a small-scale riverine fishery(Journal of National Science Council of Sri Lanka, 1997) Amarasinghe, U.S.; Pushpalatha, K.B.C.Item Institutional Robustness of Culture-based Fisheries in Perennial Reservoirs of Sri Lanka(Asian Fisheries Society, 2020) Pushpalatha, K.B.C.; Kularatne, M.G.; Amarasinghe, U.S.The utilisation of irrigation reservoirs for culture-based fisheries (CBF) development is a recent development in Sri Lanka. The trends in CBF development in five reservoirs were investigated, to identify the robustness of institutional arrangements in the rural fisheries organisations (RFOs) for the sustainability of CBF. Basic socio-economic characteristics of five fisher communities showed enabling features for implementing CBF through community participation. After the introduction of CBF, fish species composition in the landings changed with the occurrence of stocked species in the landings, resulting remarkablyelevated fishers’ income ranging from 194% to 2187% in Urusita and Ampara reservoirs respectively. The CBF management options of RFOs in two reservoirs, viz. Ampara and Jayanthi were at high compliance levels of Ostrom’s modified design principles, where fishers enjoyed increased mean annual income registering 2187% in Ampara and 409% in Jayanthi reservoirs after introduction of CBF. In Senanayake Samudra, where there was moderate compliance, there was 249% increase in CBF income. However, the lowest increase of income (194%) in Urusita reservoir was due to high annual fisheries income even during pre-CBF period. In Hambegamuwa reservoir, where levels of compliance of RFOs with design principles were relatively poor compared to other four fisher communities, increase of fishers’ CBF income, compared to that of pre-CBF period, was marginal (202%). Economic gains of RFOs due to increased levels of compliance with design principles through improving leadership qualities and empowering fishers for management decision-making would,therefore,ensure sustainability of CBF.Item Production trends and technical efficiencies of culture‐based fisheries in five tropical irrigation reservoirs: A case study from Sri Lanka(Fisheries Management and Ecology, 2020) Pushpalatha, K.B.C.; Kularatne, M.G.; Chandrasoma, J.; Amarasinghe, U.S.Culture‐based fisheries (CBF) are increasingly accepted as strategies for enhancing inland fisheries, especially in tropical Asia. In Sri Lanka, CBF development in irrigation reservoirs has gained momentum due to concerted efforts of government fisheries authorities for inland fisheries enhancement. In the present study, production trends of five irrigation reservoirs of Sri Lanka before and after the introduction of CBF were investigated and apparently optimal CBF yields were not realised. Hence, the stochastic frontier production function (SFPF) was employed to quantify technical efficiencies (TE) of CBF. For each reservoir, annual averages of input data from 2005 to 2018 (14 years) were used in the TE analysis. Hence, total sample size for estimation of SFPF was 70. Although CBF production gradually increased in all five reservoirs from 2005 to 2018, there were substantial variations of total fish production across the reservoirs. The SFPF indicated that CBF production could be further increased through more efficient management of inputs (i.e. number of fishers, mean number of fishing days per year and stocking density). https://onlinelibrary.wiley.com/doi/full/10.1111/fme.12460?af=RItem STRATEGIES FOR SUSTAINABLE DEVELOPMENT OF CULTURE- BASED FISHERIES IN PERENNIAL IRRIGATION RESERVOIRS OF SRI LANKA(2020) Pushpalatha, K.B.C.In the recent past, culture-based fisheries (CBF) development in small village reservoirs of Sri Lanka has gained momentum. Due to the extensive availability of medium and major reservoirs in the country, further expansion of CBF in such water bodies would be important to increase the food fish supply for rural people and to improve living conditions of rural communities through elevated rural income derived from CBF. However, it is necessary to develop strategies for effective management of CBF in medium and major reservoirs, based on holistic approaches due to the reason that the fisheries in these reservoirs are essentially socio-ecological systems. In the present study, attempt were made to define effective strategies for sustainable management of CBF in five perennial reservoirs of Sri Lanka through identification of factors affecting fisheries enhancement and evaluation of institutional robustness related to CBF. It was found that standard sociological methodologies such as rapid rural appraisal and participatory rural appraisal could be effectively employed to identify issues and constraints relevant to sustainability of CBF and to mobilize rural reservoir fisher communities for planning CBF. The rural fisheries organizations (RFOs) of five reservoirs have introduced and implemented community-based management options for CBF such as strict enforcement of fisheries regulations, installation of barrier nets near the sluicegates of reservoirs to prevent escape of stocked fish, establishment of revolving fund to meet expenditure for stocking and to support sound welfare activities, and introduction of effective data recording systems which facilitated CBF planning. All these strategies had a significant positive influence on CBF production enhanced rural economy and improved living conditions of fishers. A stochastic frontier production (SFP) approach was employed to evaluate technical efficiency of CBF in five reservoirs. This indicated that efficient irrigation management facilitating further increase of input factors that would depend on the reservoir extent would be important for sustainability of CBF. Many input factors of SFP such as stocking density, number of fishers which could be further increased were depend on reservoir extent. Furthermore, institutional robustness pertaining to CBF in the five reservoirs, as evaluated against Ostrom’s modified design principles was found to be strengthened through empowering RFOs which would require strong intervention of extension mechanisms of the fisheries authorities.