Rice fields to prawn farms: a blue revolution in southwest Bangladesh?

This paper examines freshwater prawn (Macrobrachium rosenbergii) farming in southwest Bangladesh where a large number of farmers have converted their rice fields to export oriented prawn farms, locally known as gher. The gher design potentially provides good opportunities for diversified production of prawn, fish, rice and dike crops, that has brought about a ‘blue revolution’. The average annual yield of prawn, fish and rice was estimated at 467, 986 and 2,257 kg ha⁻¹, respectively. Large farmers produced higher production due to more inputs, larger farm size and longer experience of prawn farming than others. All farmers in different gher size categories (i.e., small, medium and large) made a profit, with seed and feed dominating variable costs. Despite a higher production costs per hectare, the average annual net return was higher in large farms (US2,426), compared with medium (US2,426), compared with medium (US1,798) and small (US$1,420) farms. Prawn production in gher systems has been accompanied by a great deal of social and economic benefits. Most farmers associate the blue revolution with increases in income and living standards. Socio-economic benefits of the households of prawn farmers depend on resource ownership (i.e., farm size) and are very apparent. Nevertheless, a number of significant challenges, particularly social and environmental issues, are vital in translating its benefits effectively to the thousands of rural poor.     

Economic feasibility of prawn Macrobrachium production in South Carolina,USA

Cost and returns were estimated for freshwater prawn Macrobrachium rosenbergii farming as a supplemental enterprise in South Carolina in relation to the following factors: (1) existing versus new investment for ponds and water supply; (2) three stocking strategies (postlarvae alone, a 50:50 mixture of postlarvae and nursed juveniles and nursed juveniles alone) at various densities (2·15–8·61 prawns m^?2); (3) a range of prices for seed stock ($0–50 per thousand); and (4) two marketing alternatives (sale of product as shrimp tails only or with the large animals marketed heads-on and the rest as tails). Net revenue estimates indicate that prawn aquaculture has potential to become a source of supplemental income to farmers in the coastal plain area of South Carolina and throughout much of the southeastern United States. This is especially likely if the enterprise can utilize existing pond facilities that are already discounted into the value of the land or were constructed during a period of lower investment costs. A prawn farm is unlikely to be profitable if postlarvae alone are stocked, even in existing facilities, but if a mixture of postlarvae and juveniles or juveniles alone are stocked in existing facilities, profitability is likely at seed costs up to about $40 per thousand.     

Current status and prospects of farming the giant river prawn Macrobrachium rosenbergii (De Man) and the monsoon river prawn Macrobrachium malcolmsonii (H.M. Edwards) in India

Freshwater prawn production in India that includes farming and wild capture of the giant freshwater prawn, Macrobrachium rosenbergii and the monsoon river prawn, M. malcolmsonii has increased steadily since 1999 reaching a peak output of 42 780 t in 2005, but then declined to 6568 t in 2009–2010. Stunted growth and diseases in ponds because of poor seed quality and the broodstock which had been inbred over several generations; pond water quality issues; and increased cost of production on account of feed, labour and the mandatory certification requirements are suggested to be some of the factors leading to the production declines. While majority of the output occurs in Andhra Pradesh, single crop paddy–prawn production systems in the low‐lying fields of Kerala have helped gradual transformation to a sustainable, organic mode of farming of both rice and prawns, suitable for other states of India. Although the trends by June 2011 indicate that the sector is set to a revival, future prospects of freshwater prawn farming in India will also depend on the expansion of whiteleg shrimp Litopenaeus vannamei that was introduced recently in India and provided a more profitable opportunity for farming.     

An Economic Analysis of Freshwater Prawn, Macrobrachium rosenbergii, Farming in Mymensingh, Bangladesh

This paper deals with production systems, cost structure, and profitability of freshwater prawn, Macrobrachium rosenbergii, farming in a new area of Mymensingh district in the north‐central part of Bangladesh. In the study area, prawn farming practice is still extensive, and only a few farmers (20%) cultivate semiintensively. The costs and returns of extensive and semiintensive farming systems are compared. All farmers in different farming systems made a profit, with seed and feed dominating variable costs. Considerable variation in production costs and profitability was observed. Based on the Cobb–Douglas production function model, return to scale indicates that there is scope to increase production and income from prawn farms in extensive and semiintensive systems by applying more inputs (i.e., seed, feed, and fertilizer).     

Economic feasibility of recirculating aquaculture systems in pangasius farming

This study aims to analyze the economic feasibility of recirculating aquaculture systems (RAS) in pangasius farming in Vietnam. The study uses a capital budgeting approach and accounts for uncertainty in key parameters. Stochastic simulation is used to simulate the economic performance of medium and large farms operating with a traditional system or RAS. Data are obtained through structured surveys and a workshop in the Mekong River Delta. Results show that for large farms, net present value increases from an average of 589,000 USD/ha to 916,000 USD/ha after implementing RAS. Overall, the probability that RAS is a profitable investment is found to be 99% for both farm sizes. With RAS, the crucial parameters determining profitability are price, yield, costs of fingerling, feed, and initial investment. Findings on the robustness of the economic performance of RAS are useful to support public and private decision making towards increasing the sustainability of pangasius production.     

Current status and prospects of farming the giant river prawn Macrobrachium rosenbergii (De Man) in Bangladesh

Giant river prawn (Macrobrachium rosenbergii) farming plays an important role in the economy of Bangladesh. Presently, it is cultured in around 50 000 ha area with total annual production of 23 240 t. Traditional extensive prawn farming has been expanding over the last three decades through the introduction and adoption of improved culture systems, such as culture of prawn‐carps, prawn‐shrimp‐fish and prawn‐fish‐rice as concurrent and rotational systems. Efforts for the development of improved techniques on broodstock management, seed production and rearing and grow‐out of prawn have been made over the last decade. The outcomes are low‐cost feed for broodstock, production of post‐larvae in net cages (hapa), all‐male prawn culture, periphyton based prawn‐tilapia culture, C/N based prawn culture, organic prawn farming, prawn‐mola culture and prawn‐carp‐mola polyculture. Despite the development of culture technologies, a number of challenges for sustainable development of prawn farming need to be overcome to realize the potentials of this promising sector. Good aquaculture practises at all levels and application of measures for quality control and food safety would ensure sustainable development of prawn farming in Bangladesh.     

Establishing a benchmarking for fish farming – Profitability,productivity and energy efficiency of German,Danish and Turkish rainbow trout grow‐out systems

The promotion of Blue Growth in aquaculture requires an understanding of the economic drivers influencing the sector at farm level, but the collection of reliable and comparable data at this level is time‐consuming and expensive. This study suggests an alternative strategy for qualitative sampling of freshwater trout farms in Germany, Denmark and Turkey, using a combination of existing data, group discussions and interviews with trout farmers, consultants and researchers. Nine ‘typical’ trout farming models are described, focusing on profitability, productivity and energy efficiency and allowing in‐depth comparative economic analyses of different production systems at farm level, across regions. Our results show that the majority of the farms investigated have been profitable. Turkish farms benefit from competitive advantages due to low wages, low capital investment and favourable climate conditions. Large German farms profit from local market prices and advanced farm management. Danish farms using recirculating techniques remain competitive thanks to enhanced productivity and economy of scale. However, small traditional farms in Germany and Denmark may struggle to stay competitive in the long term. Organic farms in both countries face challenges of high feed costs and comparatively low productivity with mixed success. Using edible protein energy return on investment (epEROI) as an indicator of ecological sustainability, all surveyed farms compared very favourably with the terrestrial systems of animal meat production were investigated so far.     

Freshwater prawn farming in Bangladesh: history, present status and future prospects

Within the overall agro-based economy in Bangladesh, freshwater prawn ( Macrobrachium rosenbergii ) farming is currently one of the most important sectors of the national economy. During the last two decades, its development has attracted considerable attention for its export potential. Freshwater prawn farming offers diverse livelihood opportunities for a large number of rural poor. Although the prospects for prawn farming are positive, it requires some research and development activities for long-term sustainability. This paper provides an overview of freshwater prawn farming in Bangladesh.     

ASSESSING HAWAII'S AQUACULTURE FARM AND INDUSTRY PERFORMANCE

This investigation uses farm-level data from the U.S. Census of Agriculture to evaluate the economic performance of the aquaculture industry in Hawaii. We first examine the entire aquaculture industry by assessing its profitability, efficiency, and input cost structure over time and across economic farm sizes; we then proceed to analyze the farms at the individual subsector levels of crustacean, Chinese catfish, other foodfish, and ornamental farms. The results reveal a wide variation in performance across farms, even within the same subsectors. In 2007, 57.6% of the aquafarms generated a profit; however 39.4% of the farms were found unable to cover their variable cash expenses. The presence of significant economies of scales were detected in performance with full-time operations being found more profitable and efficient than part-time operations. Finally, Hawaii's labor cost share for aquaculture enterprises is about 3.5 times greater than that found on the continental United States.     

Dusky dolphin foraging habitat: overlap with aquaculture in New Zealand

相似文献   

General introduction to the prawn pond system in taiwan

The remarkable achievements of prawn culture in recent years in Taiwan have been widely recognized. In 1984, the annual production of the grass prawn Penaeus monodon alone reached 18 000 tonnes, making it one of the most important and fastest growing aquaculture items. Its production is still increasing and its importance will continue to grow in the coming years.

When considering the progress of prawn culture, aquaculture engineering problems such as pond construction, water inlet and outlet systems, and aeration systems are of great concern. An introduction to prawn pond construction and accessory equipment in Taiwan is given, and a comparison with the representative prawn pond systems in Japan and Hawaii is made. The present problems faced in these areas and possible solutions are also discussed.     

Production economics of the emerging private fish farming industry in Bulgaria

The production economics of the emerging Bulgarian private carp and trout farming industry were assessed by surveying a representative sample of 20 private and state-controlled farms as well as visiting the National Fresh Water Fish Research Institute, the state-owned fish feed production plant and a fish processing plant.The major constraints for the development of profitable fish farming were found to be the lack of capital and the insecurity of tenure, which nonetheless, do not serve to discourage new entrants into the industry. The expected gross margin per tonne of carp produced in reservoirs or earth ponds is USD 487, while a tonne of trout farmed in concrete raceways shows a gross margin figure of USD 525. State-owned trout farms are only available for outright purchase at auctions, whereas carp farms may be rented, but only for a short term.Fish farmers could benefit from organizing themselves into producer groups in order to improve marketing and secure quality inputs. In particular, there is scope to source quality dry fish diets on both economic and environmental grounds.An extension advisory service is needed to support inexperienced new entrants and researchers should urgently evaluate what seem to be the most cost-effective methods of production.     

TECHNOLOGICAL ADAPTATION TO HARMFUL ALGAL BLOOMS: SOCIOECONOMIC CONSEQUENCES FOR THE SHELLFISH FARMING SECTOR IN BOURGNEUF BAY (FRANCE)

The economic impacts of harmful algal blooms (HABs) on the shellfish farming sector depend on their frequency, duration and intensity. Safeguarding storage and accelerated detoxification are technical solutions that could mitigate the effects of these events. This article first analyzes the economic feasibility of the technological changes that can be adopted by the shellfish farming sector in France. It then examines their associated social impacts. Finally, an application is carried out on the Bourgneuf Bay production area. The economic analysis addresses three issues related to HABs: (1) the economic performance of the shellfish farms in Bourgneuf Bay, (2) the costs of these new technologies, and (3) the economic viability of such an investment. Results suggest that only a few economically viable farms would be able to implement these technologies, yet this would not be an option for smaller, less profitable farms. Individual action within the context of a “laissez-faire” public policy, taking into account the need for technological equipment, would result in a concentration of the sector to the benefit of the largest capitalist farms, with negative effects on employment and the distribution of economic rent. Alternative ways for implementing these technological changes would require collective actions or public support.     

Using the Sustainable Livelihoods Framework to Identify Constraints and Opportunities to the Development of Freshwater Prawn Farming in Southwest Bangladesh

A conceptual framework, drawn from an approach to poverty reduction known as the sustainable livelihoods approach (SLA), is applied to understanding the role of freshwater prawn, Macrobrachium rosenbergii, farming in gher (modified rice fields with high, broad peripheral dikes) systems in southwest Bangladesh. Gher farming potentially allows incorporation of a wide variety of crops together with prawn, fish, dike crops, and rice culture. The analysis shows how, in a gher farming context, sustainable livelihoods are achieved through access to a range of livelihood assets, which are combined in the pursuit of prawn farming strategies. The study used the SLA framework as a diagnostic tool to identify ways of strengthening the livelihoods of the prawn farmers.     

Tropical spiny lobster (Panulirus ornatus) farming in Vietnam – bioeconomics and perceived constraints to development

This paper presents bioeconomic data on lobster farming in Vietnam, and perceived constraints to the development of the industry. The farms were found to be profitable, with an average benefit cost ratio of 1.44 and an average net revenue of 262 million VND year^?1 (or just under US$15 000 year^?1). Investment in the enterprise is high compared with other enterprises in the region. However, disease has the potential to devastate lobster crops and there is little information available to lobster farmers about disease prevention and management. Hence, the lobster enterprise is a high‐risk high‐return industry. The predominant perceived constraints to the development of lobster operations include water quality and temperature issues, insufficient access to credit, good‐quality affordable feed and accurate information about technology improvements in lobster farming. It seems that improving the livelihood of lobster farmers in Vietnam is dependent on reducing their dependence on wild stocks for seed and feed, improving access to credit and improving technical and market information flows. Such improvements are likely to lead to higher profitability, given high export demand and hence sustained high prices for their lobster product.     

Effects of pond preparation and feeding rate on production of Penaeus monodon Fabricius, water quality, bacteria and benthos in model farming ponds

Fibreglass pools with sediment were used as model farming ponds to investigate the interactive effects of pond preparation and feeding rate on prawn production, water quality, bacterial dynamics, abundance of benthos and prawn feeding behaviour. Pools were either fertilised 1 month (prepared) or 2 days (unprepared) prior to stocking and either ‘high’ or ‘low’ feeding rates were used. The ‘high’ rate was 5.0% (range 4–8%) wet prawn biomass/day and was similar to that recommended for commercial farms. The ‘low’ rate was 2.5% (range 2–4%) wet prawn biomass/day. Juvenile Penaeus monodon (2.0–7.5 g) were stocked at 15 prawns/m² and were cultured for 71 days. With the exception of one prepared, high feeding-rate pool where mass mortality (> 80%) of prawns occurred following an interruption to aeration, prawn survival was high (> 86%) and was unaffected by preparation, feeding rate or their interaction. Pond preparation improved growth and biomass gain by about 20%. Growth was 4% higher with the higher feeding rate but biomass gain was not affected and, as food conversion ratio was much worse, use of the lower feeding rate offers considerable scope to reduce production costs, especially during cooler periods. There was no interaction in relation to growth between pond preparation and feeding rate. Meiofauna were more abundant, and prawns grew faster, in prepared pools than unprepared pools at the start of the experiment. However, changes in bacterial dynamics or meiofauna abundance over time did not explain reductions in prawn growth over time. In general, water quality was reduced in pools receiving the high feeding rate compared with low feeding rate pools. Other interactive effects of pond preparation and feeding rate on water quality, bacteria, benthos and prawn feeding behaviour are discussed.     

Freshwater prawn farming: global status, recent research and a glance at the future

A review of the current status of freshwater prawn farming globally, with comments on the statistical information available is provided in this symposium keynote paper. A brief overview of the research on freshwater prawn farming that has been published in international journals since 2000 is also provided. Finally, some research needs are listed and some scenarios for future expansion are explored.     

Pollution control options for Australian prawn farms

Abstract

The adverse environmental consequences of shrimp farming in Asia and South America have caused widespread public concern. One of the main environmental impacts is the high nutrient load that is discharged from ponds, as part of the management routine aimed at maintaining pond water quality. In Australia, where there is a high level of community awareness of the problems associated with eutrophication, the Environmental Protection Agencies are faced with the difficult task of determining effluent control policies for the emerging prawn industry.

According to the standard environmental economic arguments relating to the design of pollution control instruments, the choice of the best policy instrument depends upon the nature of the pollution problem, the costs of abatement and the transactions costs associated with administering the policy. Thus, in order to assess the appropriateness of alternative pollution control instruments it is necessary to examine the nature of the pollution problem, the technologies available for abatement, the accuracy and cost of monitoring and enforcement.

These practical aspects are examined from the perspective of the intensive prawn aquaculture industry. While there are insufficient data to conduct an empirical analysis of the relative effectiveness of alternative control measures, some of the key issues that need to be considered in designing such policies are highlighted. These issues are reviewed in the context of proposed changes to policy regulating prawn farms in Queensland.     

Production and economic efficiencies of intensive black tiger prawn (<Emphasis Type="Italic">Penaeus monodon</Emphasis>) culture during different cropping seasons in the Mekong delta,Vietnam

Production management of intensive prawn farming strongly differs between dry and wet season in terms of availability and quality of prawn seeds and water quality. Secondary data implied that prawn seed batches from the market had a total pathogen infection rate of 53%, predominantly caused by 37% white spot syndrome virus (WSSV), 19% monodon baculovirus (MBV) and 4% yellow head virus (YHV). Pathogen-free seed batches averaged to 52% during the dry season compared to the wet season (42%). Survey revealed average stocking density of 17 PL m⁻² with a survival rate of 55%, a crop yield of 2,470 kg ha⁻¹ crop⁻¹ and a net income of 6,768 USD ha⁻¹ crop⁻¹. Average production cost amounted to 3.4 USD kg⁻¹, and feed cost accounted for 58% of the production cost. Technical efficiency with respect to prawn yield and survival rate was higher during the dry season than the wet season. The probability of yield loss was 15.6 times higher in the wet than in the dry season. A positive net income can be generated for farms operating in the dry season using new ponds and performing pathogen laboratory tests on prawn seeds before stocking.