Social Sciences
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Item Evaluation of Feed Management Strategies in Shrimp Culture Ponds in Sri Lanka(University of Kelaniya, 2005) Epa, U.P.K.; Wijeyaratne, M.J.S.; de Silva, S.S.Shrimp exports have become one of Sri Lanka’s major foreign exchange earners and accounts for nearly 90% of total aquaculture exports. The average feed costs for the Sri Lankan shrimp culture industry is estimated to be around 54% of the total recurrent costs. This study evaluated different feed management strategies in commercial shrimp farms with a view to bringing about improvements. Five shrimp farms with different management practices in the north western province, Sri Lanka were selected for the study. Feed selection, storage methods, feed types, feeding frequency, ration size, feeding tray monitoring, adjustments to feeding rates, and feed conversion ratios (FCR), specific growth rate (SGR) of shrimp were recorded weekly. Blind feeding was employed in all the farms from date of stocking to 30 – 45 days. It varied from 131.5 – 219.8 kg/ 100,000 post larvae and did not increase simultaneously with stocking density. No correlation was found between the amount of feed given with SGR during the blind feeding period (p > 0.05). These results suggest the probability of over feeding during the initial stage of the culture cycle. Adjustments to feeding rates were done according to feed tray (6 – 8 trays / ha) observations, feeding guide supplied by feed manufactures and theoretical survival calculations. Feed tray observation time varied from 1 h to 2.30 h. Feeding frequency was 2 – 6 times a day. Higher variation of these parameters emphasizes the need to standardize them for optimum feed usage. Four feed management information transfer channels were identified in shrimp farms. These were (i) owner - feed marketing officer (ii) labourer – manager - consultant (iii) supervisor - manager (iv) manager only. FCR values in the farms were 2.0, 1.5, 1.4, 1.4 – 1.3 with SGR of 2.5, 2.9, 3.3, 2.6 day-1, respectively. Information channels (i) and (ii) resulted in higher FCR values. It is suggested to pay more attention on information transfer channels in order to avoid over- feeding. Blind feeding, feeding frequencies and information transfer channels were identified as crucial areas that could be improved for the sustainable shrimp culture industry in Sri Lanka. With these improvements, the cost of feeding could also be minimized.Item Stilt fishing in Southern Sri Lanka: management constraints and future sustainability(Culture, Globalization and the Developing World, 2nd ICSS, 2013) Epa, U.P.K.; Zoysa, M.C.L.Stilt fishing is one of the traditional artisanal fishing methods which cannot be seen in any part of the world except in Southern coast of Sri Lanka. This unique fishing method is identified by the supporting structure that is used by fishermen during fishing operation. In the present study, methods such as participant-observation, structured questionnaire, interviews and analysis of statistical data were used. The socio-economic data was collected from Goviyapana, Kubalgama and Talpe fishing villages in the Galle district. Though stilt fishermen are not organized into a society the fishery is managed by the fishermen by their own management strategies. Each fishing reef is used only by fishermen from a particular village or group of villages. Fishing using crafts and nets are forbidden, as are different types of hooks. Fishing rights and skills are transferred from parents to their offspring. According to the catch statistics there was a significantly positive relationship (p<0.05) between rainfall and catch per unit effort at sampling sites. There is no restriction regarding the number of stilts that could be planted in one reef a time and this activity not only damages the reef unnecessarily but also obstacle the free movement of fish in the shallow coastal waters. Offshore fishermen set their nets across the fish migratory pathways even during the stilt fishing period. The present fisheries act (No. 02 of 1996, as amended) does not contain regulations to control setting of nets across fish migratory pathways. Successful stilt fishermen have substantial knowledge of fisheries issues accumulated through informal experience that passes generation to generation. Resolving the issues related to stilt fisheries and/or provision of facilities for other fisheries related activities can help them stay in the industry or diversify. The long-term aim should be to establish resilient communities with sustainable and diversified livelihoods.