WWW.WAS.ORG • WORLD AQUACULTURE • MARCH 2016 27 FIGURE 2. Malaysian giant freshwater prawn Macrobrachium rosenbergii. FIGURE 3. Harvesting mixed carps. FIGURE 4. Harvest of black tiger shrimp Penaeus monodon. Profitability including labor cost for farmers’ practice (control) was negative in 2012, and significantly increased in 2013. Profitability of control treatment excluding labor cost was 65,000 BDT/ha per yr in 2012 and 94,000 BDT/ha per yr in 2013. Local varieties of grass and neem grew well on gher dikes. Grass grown on the gher dikes of 1-ha experimental plots provided sufficient fodder for four to five goats. Neem has potential for use in the herbal industry as a raw material. Based on rainfall from August to January, one to two crops of bottle gourd and cucumber can be grown on improved gher dikes with greater width and height. Conclusion System productivity and profitability in brackishwater aquaculture systems can be increased significantly through diversification and better management. Rotational polyculture increases fish production for local market and reduces risk of economic loss from dry season crops. Crop rotation helps reduce water salinity. Considerable opportunities exist for improving productivity, diversification and resilience of brackishwater aquaculture in the coastal saline zone of Bangladesh. Technologies appear to be very “adoptable” by farmers, as indicated by the number of farmers around experimental plots that were voluntarily adopting some of the practices, including shrimp-tilapia polyculture in the dry season, mixed culture of carp and catfish in the wet season, and growing vegetables on dikes. Water management is also a key factor in improving aquaculture within the region and adoption of community water management could further improve options for aquaculture. Preliminary experiments with growth of vegetables and fodder on dikes also suggests it is possible to integrate vegetable production on dikes in the wet season and support livestock by growing grass on the dikes. Saline water represents an asset to the country that needs to be more efficiently used in aquaculture and aquacultureagriculture farming systems. To meet growing fish demand, further intensification of such systems is needed in a sustainable way. Better understanding of market systems, improved access of farmers to quality inputs and capital investment also needs to be explored for scaling of improved farming systems and creating positive development outcomes and impacts from this research. Notes K.A. Kabir, M. Karim, C.A. Meisner, WorldFish, Bangladesh, k.kabir@cgiar.org, m.karim@cgiar.org, c.meisner@cgiar.org S.B. Saha, Bangladesh Fisheries Research Institute, Bangladesh, sbikashsaha@yahoo.com M. Phillips, WorldFish, Malaysia, m.phillips@cgiar.org Acknowledgments We acknowledge the CGIAR Challenge Program on Water and Food for providing funds for conducting this study and the CGIAR Research Program on Aquatic Agricultural Systems for further collaboration and support in analyzing these data. We also thank the WorldFish AIN project for providing additional funding for establishing experimental ponds. We are grateful to Mr. Habibur Rahman and Md. Faruk Hossen for participating in the research with their land, time and skills. Photo credit to Anisuzzaman Ujjal and Nazneen Khan.
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