Integrating agriculture aquaculture that would draw inputs from on farm sources is viewed as a viable option to improve the productivity, income and resource use efficiency of existing farms in Bangladesh. To assess the existing resource availability, use pattern and efficiency before introducing new aquaculture technology within the existing farm systems, a survey of 330 pond operating farm households was conducted in six selected unions from two thanas (subdistricts) of Bangladesh.
Author's comment on the farming of fish as a efficient means in terms of water use.
Smallholding farmers in Zomba District, Malawi have been working in partnership with ICLARM scientists to conduct controlled on-farm trials of integrated pond fish culture. In the 1993 growing season, seven smallholding farmers in Zomba District, Malawi tested the potential for integrated aquaculture of indigenous fish using locally-available resources. To scientifically control these tests, management practices and inputs used by farmers were mimicked in ponds at the National Aquaculture Center.
Among 257 Bangladesh fish ponds investigated, 46% were affected by epizootic ulcerative syndrome (EUS) either fully or partially. Thai silver barb, Puntius gonionotus (Bleeker), culture ponds were worst affected (64%) by EUS, while all Nile tilapia, Oreochromis niloticus (L.), monoculture ponds remained unaffected. Stocking of silver barb for culture, use of piscicides as means of moving predators or unwanted species prior to stocking of cultured species, and culture of fish in previously derelict ponds are factors which significantly affected the probability of occurrence of EUS.
A working hypothesis was adopted that previously reported limits to fish productivity in manured static-watersystems (2.5-3.5 g fish/m super(2)/d) are derived from an imbalance between phytoplankton productivity and harvest by fish. The assumption that an improved balance would result in greater net generation of oxygen, and phytoplankton and fish productivities was tested in a series of outdoor fertilized concrete tanks in which phytoplankton harvesting was regulated by varying the stocking density (range 0.5-10 fish/m super(2)) of thephytophagous Nile tilapia (Oreochromis niloticus)). The
Nile tilapia (Oreochromis niloticus) juveniles were manually sexed and 50, 80, 95, 98 and 100% male populations (two replicates) were stocked at a density of 1 fish-m super(-2) earthen ponds. Growth of stocked fish andrecruitment were assessed from biweekly sampling. Pond were completely harvested after 24 weeks. Recruitmentwas observed in all ponds with recruits representing 4.7 to 31.4% of total biomass at harvest. Errors from manual sexing resulted in small numbers of female being stocked and subsequently some recruits occurring in the all-maleponds.
The success of aquaculture among small holder farmers in Malawi, depends on the use of the available on-farm resources. Commercial fish feeds are currently not available. Fish ponds open possibility for recycling of waste products and nutrient when integrated with crop and/or animals on the farm. The inputs used for growing fish increase the nutrient content of water and sediments.
This paper describes the technical and economic efficiency of tllapla aquaculture in small ponds and ditches in Trishal. Fulbarla and Mymensingh thanas (village units). Bangladesh. Sample surveys of 11 3 and 46 farmers were used in estimating linear and log-linear (Cobb-Douglas) production Functions, respectively. Results from the linear model which gave the better fit showed that the rate of Fingerling stocklng and the use of rice bran have significant effects on tllapla production. This model also indicated that there were different productivities across locations and pond sizes.
The study aimed to investigate the effect of Echinacea on survival and growth rates of Nile tilapia (Oreochromis niloticus), its immunostimulatory and disease control effects via changes in various hematological and immunological measures, and its impacts on resistance to challenge infection tests.
Fish harvesting methods have been long reported to be one of the major bottlenecks to the development of ruralaquaculture in Malawi (Ministry of Natural Resources and Surveys 1962). Most fish are harvested with nets borrowed from fisheries departments, leading to overdependence of farmers on the government.