The present research is based upon a comprehensive survey which discusses the slightly tolerable water level of Balaton between 2000 and 2003. The low water level of the extreme period caused considerable problems in ...The present research is based upon a comprehensive survey which discusses the slightly tolerable water level of Balaton between 2000 and 2003. The low water level of the extreme period caused considerable problems in recreation. Our goal was to investigate the possible water transfer policies and the water level regulation policy of Lake Balaton by applying the dynamic programming of Markov chains. This iteration supports the cost-benefit analysis of different scenarios and also provides information about the best water governing policy. As a basis of our scientific analysis, Markov chains were created by ARMA （autoregressive moving average） synthetic data generator. Profit was joined to each transition-probability for the economic analysis. In our case the profit was negative, because the harmful effects of the low water level should be estimated, which is based on the calculated willingness-to-pay for improving the water quality of Lake Balaton. In addition, the profit includes the cost of different water supplement scenarios. After computer programming, the method proved to be an efficient tool to buttress the cost-benefit analysis of water supplement scenarios. The result highlights the importance of further climate change monitoring. Calculation confirmed water transfer to be cost-effective, yet scenarios with less ecological risk are also effective, thus preferable.展开更多
The study was aimed at evaluating growth response of Heteroclarias fingerlings fed diet in which fish meal was substituted with graded levels of earthworm meal. The replacement levels were 0.00%, 25%, 50%, 75% and 100...The study was aimed at evaluating growth response of Heteroclarias fingerlings fed diet in which fish meal was substituted with graded levels of earthworm meal. The replacement levels were 0.00%, 25%, 50%, 75% and 100% designated as Eo, E25, Es0, E75 and El00, respectively. Fingerlings used for the work were obtained through artificial insemination of brood stock （purchased from local farmers） with ovaprim in the laboratory. The resulting fry were reared and fed with cultured plankton for 2 weeks followed by 100% fish meal for another two weeks. Thereafter sixteen fingerlings weighing 4.73 g and measuring 6.512 mm standard length （on the average） were starved over night and reared in five indoors tanks （0.8 ~ 0.5 ~ 0.5 m） in duplicate for eight weeks. Fingerlings were fed on graded earthworm meals of 40% protein twice daily at 08：00 and 16：00. The highest mean weight （6.77 g）, specific growth rate （0.86） and protein efficiency ratio （0.6） were obtained at 50% replacement level. Also, Food conversion ratio was the highest at 50% substitution level and lowest at 0.00% substitution, indicating that fingerlings use earthworm containing meal more efficiently. Furthermore, cost benefit analysis revealed that the profit index for 50% inclusion of earthworm meal was the highest （1.71） and the highest net profit of N374.32 （circa $2.3） was achieved at this level. Water quality parameters observed were within tolerable values for the fingerlings well being. Consequently, farmers are advised to use 50% earthworm meal in place of fish meal for formulation of Heteroclarias fingerlings diet. This will drastically reduce production cost, increase farmers profit and enhance the biological value of our menu.展开更多
文摘The present research is based upon a comprehensive survey which discusses the slightly tolerable water level of Balaton between 2000 and 2003. The low water level of the extreme period caused considerable problems in recreation. Our goal was to investigate the possible water transfer policies and the water level regulation policy of Lake Balaton by applying the dynamic programming of Markov chains. This iteration supports the cost-benefit analysis of different scenarios and also provides information about the best water governing policy. As a basis of our scientific analysis, Markov chains were created by ARMA （autoregressive moving average） synthetic data generator. Profit was joined to each transition-probability for the economic analysis. In our case the profit was negative, because the harmful effects of the low water level should be estimated, which is based on the calculated willingness-to-pay for improving the water quality of Lake Balaton. In addition, the profit includes the cost of different water supplement scenarios. After computer programming, the method proved to be an efficient tool to buttress the cost-benefit analysis of water supplement scenarios. The result highlights the importance of further climate change monitoring. Calculation confirmed water transfer to be cost-effective, yet scenarios with less ecological risk are also effective, thus preferable.
文摘The study was aimed at evaluating growth response of Heteroclarias fingerlings fed diet in which fish meal was substituted with graded levels of earthworm meal. The replacement levels were 0.00%, 25%, 50%, 75% and 100% designated as Eo, E25, Es0, E75 and El00, respectively. Fingerlings used for the work were obtained through artificial insemination of brood stock （purchased from local farmers） with ovaprim in the laboratory. The resulting fry were reared and fed with cultured plankton for 2 weeks followed by 100% fish meal for another two weeks. Thereafter sixteen fingerlings weighing 4.73 g and measuring 6.512 mm standard length （on the average） were starved over night and reared in five indoors tanks （0.8 ~ 0.5 ~ 0.5 m） in duplicate for eight weeks. Fingerlings were fed on graded earthworm meals of 40% protein twice daily at 08：00 and 16：00. The highest mean weight （6.77 g）, specific growth rate （0.86） and protein efficiency ratio （0.6） were obtained at 50% replacement level. Also, Food conversion ratio was the highest at 50% substitution level and lowest at 0.00% substitution, indicating that fingerlings use earthworm containing meal more efficiently. Furthermore, cost benefit analysis revealed that the profit index for 50% inclusion of earthworm meal was the highest （1.71） and the highest net profit of N374.32 （circa $2.3） was achieved at this level. Water quality parameters observed were within tolerable values for the fingerlings well being. Consequently, farmers are advised to use 50% earthworm meal in place of fish meal for formulation of Heteroclarias fingerlings diet. This will drastically reduce production cost, increase farmers profit and enhance the biological value of our menu.
