Three low cost aquaculture technologies such as polyculture of carps and monoculture of Nile tilapia and monoculture of silver barb were developed and introduced to the farmers based on their socioeconomic conditions and pond attributes. Their common feature is reliance on on-farm resources, through integrating aquaculture into the existing farming systems. Among the socioeconomic factors affecting farmers' adoption of these technologies, training was the key variable.
In the State of Assam, floodplains cover 2.6 million ha of area that is traditionally rice growing. The ecosystem in the rice-growing areas has undergone major changes as a result of various developmental activities and adoption of modern farming technology. Rice fields were once the major source of fish for the rural farmers. There has been a sharp decline in fish population in rice field leading to a chronic shortage of fish in the State and a deterioration of the rice ecosystem.
The production of snakeskin gourami (Trichogaster pectoralis) from wild stocks and traditional culture systems has been declining in central Thailand, although they are on the increase in modern culture practices adopted in some provinces. Net yields of T. pectoralis in traditional systems are about a third of those in modern systems. The potential of T. pectoralis as a candidate for more intensive waste-fed polyculture appears promising if seed supply constraints can be removed.
To measure the impact of past projects on the sustained adoption and development of aquaculture, and to assess the potential for future growth, a participatory rural appraisal (PRA) based on the Research Tool for Natural Resource Management, Monitoring and Evaluation (RESTORE) of 100 farmers (62 with fishponds, 38 without) was undertaken between January and August 2001 in the Noun Division of Western Province, Cameroon. The average household of 14 persons possessed 5.5 ha of land. Educational level is low (less then 35% above primary, 24% illiterate).
Mixed sexes of Oreochromis shiranus and Tilapia rendalli were stocked in 5-m super(3) concrete tanks in the ratios of 0:100, 25:75, 100:0 and 75:25, at the rate of 6 fish m super(-2). O shiranus and T. rendalli were stocked at mean body weights ( not equal to SD) of 12 not equal to 0.4 g and 12 not equal to 0.7 g, respectively. Cabbage and pumpkin leaves were added to the tanks at a rate chosen to simulate pond conditions (50 kg dry matter (DM) ha super(-1) day super(-1)) as bundles tied with wire, fully submerged at a depth of about 30 cm.
The large body of information available on tilapia biology and culture presents a confusing picture to the prospective culturist. Further stock improvement and standardization of intensive culture methods are needed. Concentration on a few species - Oreochromis aureus, O. niloticus, their hybrids and the 'red' tilapias will facilitate progress. the macrophyte-feeder Tilapia rendalli may also have potential particularly for polyculture with microphagous tilapias. International cooperation is recommended for establishing research facilities and programs.
Three major carp species, viz. catla Catla, Labeo rohita and mrigal Cirrhinus mrigala, are farmed in polyculture systems in the southern state of Andhra Pradesh, India. A survey of 189 carp farms was undertaken, and principal component analysis was used to assess the relationships between farm inputs and fish yield. Model results exhibited a strong relationship of yield with the stocking density of all three major carp species.
The potential benefits of using giant clam farming systems to rear trochus for restocking were investigated in Solomon Islands.
A study was undertaken to determine fish species combinations that would result in optimum production levels in integrated broiler raising systems. Its objectives were: (i) to evaluate the production potential of fish in integrated poultry-fish systems using high yielding varieties of broilers; (ii) to identify which fish species combination would result in optimum production levels; (iii) to estimate the effects of varying ratios of Catla catla and Hypophthalmichthys molitrix in stocking on gross production; (iv) to assess the production potential of O.
This paper evaluates resource allocation efficiency of prawn-carp polyculture systems by making use of the data of 105 farmers of Bangladesh. Data Envelopment Analysis (DEA) was employed to estimate the efficiency. Mean technical efficiency (TE), allocative efficiency (AE) and cost efficiency (CE) were 85%, 58%, and 49%, respectively. Fifty percent of prawn-carp farmers displayed full TE whereas only 9%were cost efficient. Actual input application largely deviated from the technical and cost-efficient levels.