A discussion is presented on the topic of pond stirring in aquaculture as a means of increasing productivity of the fish ponds. Pond stirring may be done either mechanically or by using aquatic organisms (bioturbation), and increases the nutrients in the water column and resulting microbial production, also supplying food and surfaces for microbial colonization for consumption by fish.
The growth of aquaculture - now the fastest growing food production system in the world - is increasingly attracting private investment. Much of this investment, however, is in larger enterprises and input services such as feed, seed and processing. Little is targeted at smallholder farmers who, as a result, continue to face constraints in accessing finance, technology and markets. In 2010, WorldFish set out to explore the business case for investment in smallholder aquaculture by examining several donor funded projects.
Fish has been a staple food for over a billion people. Its demand is increasing due to growing population and awareness about health benefits of aquatic animal food. Disappointingly, wild catch worldwide is on the decline and aquaculture is emerging as the only solution. It grew at 9%/yr in the last 10 years becoming the fastest growing food production sector. At present, aquaculture produces only about 45 million t per year but it needs to be doubled by 2030 to meet its growing demand. Asia produces over 85% of the global farmed fish - mostly by small-scale farmers.
The potential of small-scale aquaculture (SSA) to contribute to development goals including poverty reduction and improved food security has been widely discussed. These accounts emphasize the following characteristics of SSA: the relative poverty of practising households; the subsistence or semi-subsistence nature of the activity; its role as a means of agricultural diversification; its contribution to food security; family ownership and operation of production or reliance on predominantly family labour; and utilization of small areas of land and/or water.
An account is given of shrimp farming and its benefits to India, discussing effective land use, the use of naturalshrimp seed resources, foreign exchange and employment in rural areas.
Aquaculture is still the fastest-growing food-producing sector and plays an important role in enhancing global food security and alleviating poverty. Tens of millions of people are engaged in aquaculture production, the majority of whom are small-scale farmers who have limited resources and are faced with difficulties due to increasing globalization and the resultant trade liberalization of aquaculture products. Despite these challenges, small-scale farmers remain innovative and continue to contribute to global aquaculture production.
Econometric techniques were used to estimate a production function for tilapia pond culture in El-Fayum Governorate, Egypt, utilizing cross-sectional field data. Explanatory variables were feed, initial stocking weight, and pond size. The function was used to examine returns to scale, estimate the productivity of feed and initial stocking weight, and estimate the profit maximizing demand equations for feed and fingerlings. Diminishing returns to scale seem to exist for tilapia pond culture.
Fish production in Vietnam increased rapidly from 420 000 t in 1981 to 1 130 680 t in 1998. Likewise, there was an expansion in the number of motorized fishing boats from 29 584 units with an average horsepower (HP) of 19.8 boat-1 in 1981 to 71 800 units with an average HP of 26.2 in 1998. In 1995, fish production was valued at VN$2 475 billion (US$0.02 billion at 1 US$ = 11 041 VN$; source: oanda. com).
A brief account is given of the results of a grow-out trial conducted regarding the freshwater prawn (Macrobrachium rosenbergii ) in a farm pond in Ghana with water at temperatures of 30-33 C. Results showed that 70% of the prawns achieved lengths of over 13 cm and wet weight of > 35 g, figures which compare favourably with growth rates achieved in other parts of the world. Although M. rosenbergii culture is viable in Ghana, problems exist which prevent further development, the major one being lack of foreign exchange to purchase juveniles.
The rural populations of southern Bangladesh are some of the most vulnerable communities in the world to the future impacts of climate change. They are particularly at risk from floods, waterlogged soils, and increasing salinity of both land and water. The objective of this project was to analyze the vulnerability of people in four villages that are experiencing different levels of soil salinity.