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1.
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2.
Abstract

Modern aquaculture is a relatively new activity among Nepalese farmers and a small contributor to the economy. Given the abundance of water resources and fish species, rising demand for fish, and its high profitability, aquaculture has potential for future expansion if it is given appropriate attention from the government. In Nepal, productivity in aquaculture is much lower compared to other countries in the region, which suggests that there is potential for increased fish production through technological progress and improvement in farm‐level technical efficiency. However, no formal analysis has yet been conducted to assess the productive performance of Nepalese aquaculture and its potential for future improvement. Against this background, this paper examines the technical efficiency and its determinants for a sample of fish pond farms from the Tarai region of the country using a stochastic production frontier involving a model for technical inefficiency effects. The estimated mean technical efficiency is 77%, with intensive farms being more efficient than extensive farms. The adoption of regular fish, water, and feed management activities has a strong positive effect on technical efficiency.  相似文献   

3.
Economic contribution of fish culture to farm income in Southeast Vietnam   总被引：1，自引：1，他引：0  
Rural aquaculture is the farming of aquatic organisms with extensive and semi-intensive husbandry practised by small-scale rural households for their consumption and income. From a field survey in Southeast Vietnam, using enterprise budget analysis and nonparametric tests with indices of change, adoption, and agreement, this study justifies that rural aquaculture is a good option for rural development, making an important contribution to farm income with a high adoption rate among poor farmers. Fish farmers have gained an increased level of satisfaction by means of fish culture production growth along with corresponding economic gains. This enterprise continues to play an increasing important role in their livelihoods and has potential to develop further in the area.  相似文献   

4.
ABSTRACT

Asian aquaculture has been contributing in great measure to the global fish basket. The Indian subcontinent, with a rich biodiversity of fish species, has emerged as an important aquaculture country, particularly in the freshwater environment. Carps form the mainstay of culture practices in the country, supported by a strong traditional knowledge base and scientific input in various aspects of biology, environment, nutrition, and health management. New species and culture systems, integration with other farming systems, use of organic material as nutrient inputs, and depuration measures in waste-fed culture systems are being considered for enhancing aquaculture productivity. This article presents the status of grow-out production of carps in India and traces the growth of the practices over the decades as well as the potential of the sector.  相似文献   

5.
Abstract

The catfish industry is the most successful aquaculture business in the US. The development and growth of the catfish industry has resulted in complex fish farm businesses that require intensive management. Technological innovations have resulted in increased yields (land use efficiency). However, in more recent years, productivity gains have not kept pace with the rate of increase in input costs. Increasing intensification of catfish production over time has been accompanied by increased use of debt capital that results in higher levels of financial risk. While still a profitable activity, real profit margins have declined as financial risk has increased. New technologies will likely continue to increase productivity over time. Market‐oriented agribusiness approaches to catfish marketing are likely to become the norm. The challenge for the catfish industry is to coordinate adoption of new higher‐cost technologies with demand increasing market development to sustain farm price levels.  相似文献   

6.
Abstract

We evaluate the profitability and technical efficiency of aquaculture in the Philippines. Farm‐level data are used to compare two production systems corresponding to the intensive monoculture of tilapia in freshwater ponds and the extensive polyculture of shrimps and fish in brackish water ponds. Both activities are very lucrative, with brackish water aquaculture achieving the higher level of profit per farm. Stochastic frontier production functions reveal that technical efficiency is low in brackish water aquaculture, with a mean of 53%, explained primarily by the operator's experience and by the frequency of his visits to the farm. In freshwater aquaculture, the farms achieve a mean efficiency level of 83%. The results suggest that the provision of extension services to brackish water fish farms might be a cost‐effective way of increasing production and productivity in that sector. By contrast, technological change will have to be the driving force of future productivity growth in freshwater aquaculture.  相似文献   

7.
Abstract

Black bream (Acanthopagrus butcheri) appear an ideal candidate for the developing saline aquaculture industry of inland Western Australia. However, current maximum growth rates of 150g/annum are too slow for profitable production. This study investigated whether enhanced growth rates of black bream would improve profitability and justify a genetic improvement program. A partial budget analysis was conducted for two different fish production systems; a commercial operation that incurred more operating expenses due to costs associated with farm initiation (stand‐alone farm model), and an existing farm that diversified into aquaculture using the saline water resources of established farm dams (integrated farm model). Sensitivity analyses indicated that a 33 per cent increase in growth rate to at least 200g/annum would allow either production system to return a profit at a farm‐gate price of AUS$6/kg whole fish, with fish survival rates of 98 per cent for the stand‐alone farm, and 65 per cent for the integrated farm model. These results are discussed in the context of the genetic and economic consequences of selection for improved growth rates, and for developing breeding objectives and a genetic improvement program for black bream.  相似文献   

8.
ABSTRACT

The paper reviews freshwater and coastal aquaculture practices in Thailand, and compares the productivity, costs, and benefits across various types of cultivation and various intensities of production. The paper is based on data that were collected in surveys conducted during 1998–2001 by the Department of Fisheries (DOF), Thailand and the WorldFish Center. More than 22% of Thailand's fish supply comes from aquaculture, with coastal aquaculture accounting for more than 88% of this in terms of value. Intensive culture of shrimp is the dominant form of coastal aquaculture, occupying 69% of the area under production. However, in some regions, the average net profit/kg of intensive shrimp culture is negative, and semi-intensive farming, with relatively lower fixed investment and operating costs, delivers the highest rate of return on investment. On the coast, grouper and sea bass are the most important cage-cultivated species, achieving an economic rate of return as high as 92%. In the same environment, culture of mollusks, such as green mussels, oysters, and blood cockles, is widespread. It can also be economically sustainable, with relatively low capital and operating costs. Although the relative share of freshwater aquaculture production is declining, the level of output has been increasing rapidly. While the average production from monoculture of carnivorous species is higher than that from polyculture, the average capital investment and operating costs associated with the former are also higher. The expansion of freshwater polyculture and of mollusk culture in coastal areas would greatly assist poor fish farmers.  相似文献   

9.
Aquaculture is a globally important industry that provides essential food to a growing world population, with a major role in the supply of cheap animal protein. Very rapid developments have been occurred in aquaculture sector of Egypt in recent years and exhibited the strongest growth of any fisheries-related activity in the country. As a result, aquaculture is considered as the only viable option for reducing the current gap between production and consumption of fish in Egypt. The rapid expansion in support activities such as local feed mills and hatcheries made the sector more sophisticated and diverse. Globally, Egypt ranks 9th in fish farming production and 1st among African countries. The aquaculture is practiced in different production systems including semi-intensive, intensive culture in ponds, tanks, intensive production in cages and traditional extensive production systems, but has yet to be adequately documented. Despite the fact that the aquaculture sector in Egypt has witnessed a spectacular development, it has also created challenges with respect to environmental issues and sustainability. This review provides an overview of the status and the perspectives of Egyptian aquaculture sector.  相似文献   

10.
ABSTRACT

India is a very populous country with more than one billion people. In order to provide food for this growing population, serious environmental problems may result. Despite many benefits from the green, blue, and silver revolutions adopted in India, there has been much concern resulting from intensive agricultural practices that led to environmental problems in both terrestrial and aquatic ecosystems. Increasing demand for aquatic resources also caused inland fisheries to decrease over the past few decades. The location of aquaculture projects, landscape destruction, soil and water pollution by pond effluents, over-exploitation of important fish stocks, depletion in biodiversity, conflicts over agriculture and aquaculture among various stakeholder groups over resource and space allocation, and international fish trade controversies have threatened the long-term sustainability of fisheries and aquaculture industries. The subject of sustainable aquaculture has not been adequately projected in terms of current aquaculture practices aimed to boost a rural economy. This review briefly describes the key issues of aquaculture unsustainability in terms of intensive aquaculture, nutrient enrichment syndrome, soil and groundwater salinization, destruction of mangroves, loss of biodiversity, marine pollution and loss of fish stock, use of aquachemicals and therapeutics, hormone residues, etc. The strategies for sustainability have been highlighted with respect to rice-cum-fish culture, carp polyculture, integrated farming with livestock, rural aquaculture, intensification of small farms, wastewater-fed aquaculture, crop rotation, probiotics, feed quality, socioeconomic considerations, environmental regulations and fisheries acts, transboundary aquatic ecosystems, impact of alien species, ethical aspects of intensive aquaculture, responsible fisheries, and environmental impact assessment. A suggested model outlines the feedback mechanisms for achieving long-term sustainability through improved farm management practices, integrated farming, use of selective aquachemicals and probiotics, conservation of natural resources, regulatory mechanism, and policy instruments.  相似文献   

11.
Aquaculture in the Philippines is long-established but has witnessed rapid technical change in the last 20 years with the introduction of hatchery technology and commercial feed mills changing the production possibilities for a fishpond operator. To understand the sector, a typology of brackish-water pond farming systems is constructed using multivariate methods (principal components analysis, cluster analysis). Eight input variables across all major factors of production are used in the analysis, gathered from a net sample of 136 farms in two regions in 2003. Three latent variables are described, accounting for 58% of variance in the original data: specialization; land vs. labor intensity; and feeding intensity. Five clusters (farm types) are subsequently described: extensive polyculture (40% of sample); semi-intensive prawn-oriented polyculture (11%); low-input labor-intensive farms (27%); very large, extensive milkfish-oriented farms (8%); and semi-intensive milkfish monoculture farms (14%). Implications for technical efficiency estimation and comparative study of economic indicators are discussed.  相似文献   

12.
This paper aims to examine the levels and determinants of technical efficiency in carp pond culture in India. The stochastic production frontier technique involving the model for technical inefficiency effects is applied separately to samples of semi‐intensive/intensive and extensive carp producers interviewed during 1994–95. The results showed significant technical inefficiencies in carp production in India, especially among extensive farms. The mean technical efficiencies for semi‐intensive/intensive and extensive sample farms were estimated to be 0.805 and 0.658 respectively. By operating at full technical efficiency levels, the semi‐intensive/intensive farms could, on average, increase their production from about 3.4 Mt ha?1 to 4.1 Mt ha?1. Likewise, the extensive farms could increase their production from 1.3 Mt ha?1 to 1.9 Mt ha?1. Much of these efficiency gains would come from improvement in the adoption of recommended fish, water and feed management and monitoring practices. Besides expanding production area, the results indicated several other possibilities for increasing carp production in India by increasing yields per hectare, such as: (1) increased intensification of carp culture (i.e. moving from extensive to semi‐intensive or intensive systems); (2) improvement in technical efficiency at the farm level; and (3) technological progress. However, the realization of these potentials will depend on continuous efforts by the government in ensuring an adequate supply of inputs, technology transfer and development and adequate provision of research, extension and credit services in aquaculture.  相似文献   

13.
Israel has a temperate climate with marked differences between the northern and southern regions. Rainfall ranges between 250 and 600 mm year−1 in the former and between only 25 and 200 mm year−1 in the latter. During the last 30 years, water consumption has increased markedly in all sectors. Although a water allocation for inland aquaculture is made, in most cases it is given the lowest priority, and aquaculturists have learned to contend with difficulties, and thrive on brackish water sources not fit for human consumption or agricultural crops. Since most water sources are already fully exploited, further development of all sectors will depend on their respective capacity to use recycled city water, desalinated brackish or sea water, or recycled pond water. In this respect, inland aquaculture is handicapped by public prejudices which will not allow the use of water from the first source and farms are still not able to cope with the cost of the second. Therefore, further development of inland aquaculture will depend on the capacity of farmers to use sea water, and to recycle pond water time and again to produce more fish with less (inland) water. Various strategies have already been developed in Israel and new ones are under study. These include water harvesting in dual-purpose reservoirs, recycling of pond water from one year to another, development of intensive flow-through systems based on recycled pond water and colleagues based on biofiltration.  相似文献   

14.
Abstract

Farmers throughout the wheatbelt of Western Australia are interested in farming rainbow trout, Oncorhynchus mykiss, in saline groundwater on salt-affected farmland, to generate an alternative source of income. We compared the relative productivity and profitability of three different production systems: extensive (trout stocked in earthen ponds and totally reliant on natural food); semi-intensive (trout stocked in earthen ponds and provided with supplementary diet); intensive (trout stocked in closed, recirculating tanks). The yield of fish increased with increasing production intensity. The mean wet weight (±SE) of trout after 4 months of grow-out was 61.3±2.7 g in extensive systems, 157.9±5.2 g in semi-intensive systems and 137.9±3.9 g in intensive systems, giving mean yields of 10.8 kg/pond (13.5 kg/ha), 27.9 kg/pond (34.8 kg/ha) and 54.9 kg/tank (21.1 kg/m3), respectively. A preliminary economic analysis of the different production systems showed that the increases in yield were sufficient to balance the extra operating costs involved in semi-intensive systems, but not in intensive systems. We conclude that semi-intensive production systems deserve further study for the commercially viable production of rainbow trout from saline groundwater in Western Australia.  相似文献   

15.
This article analyzes the effects of agglomeration externalities on productivity and efficiency by applying a stochastic production frontier model with a technical inefficiency model to the aquaculture industry. Agglomeration externalities refer to the costs and benefits to firms from clustering. Agglomeration studies within aquaculture have focused on the intensive salmon industry, whereas this study focuses on low-technology, extensive pond aquaculture, representing most farmers in the developing world and using Bangladesh as an empirical case. The results show that there is a positive externality effect of regional industry size on the production possibility frontier and a negative effect on technical efficiency. Farm density enhances efficiency and the farm proximity to output markets decreases efficiency. Thus, policies aimed at increasing aquaculture pond production in developing countries should consider farm locations and their access to input and output markets, all of which affect farm productivity and efficiency.  相似文献   

16.
During the past 20 years there has been a dramatic global expansion in fish farming, with both positive and negative consequences. Although commercial aquaculture has contributed positively to the economies of many producing countries, there are considerable negative environmental and social impacts. In intensive and semi-intensive systems, artificial feeds supplemented with antibiotics are used to prevent the spread of disease and to improve feed conversion ratios. Current knowledge of the health and environmental impact of antibiotics used in aquaculture is poor, particularly in tropical regions. Residues may remain in fish used for human consumption and antibiotics released into the environment can lead to the development of antibiotic-resistant bacteria in the food chain. The accumulation of waste feeds in ponds stimulates the growth of bacteria, including human pathogens, which can contaminate products and lead to foodborne disease and the rejection of products in export markets. In extensive systems, where fish are produced mainly for the domestic market, different food safety concerns exist. The consumption of aquatic plants and raw or partially cooked freshwater fish has been associated with foodborne trematode infections. These are a major public health problem in East and South East Asia and occur when products that are contaminated by the infective stages of the parasites are consumed. This paper reviews food safety hazards associated with products from aquaculture and proposes the application of principles of the hazard analysis critical control point (HACCP) system as a general strategy to control the hazards identified.  相似文献   

17.
The optimal use of resources in aquaculture is important, especially in developing countries, to obtain the highest possible outcome from the production process to support food security and poverty alleviation. Thus, within this study, the risk, efficiency, and input‐use variation in aquaculture farms in Bangladesh is investigated using a flexible stochastic frontier model with a risk and an inefficiency function. The results reveal that feed, labor, and capital have positive and significant impacts on production. In addition, an increased fingerling density and a larger farm increase the risk, whereas the use of feed and the capital invested have the opposite effect. Access to extension services has a positive effect and increases farm efficiency. An investigation of the farm size–productivity inverse relationship reveals that this phenomenon is not applicable to Bangladesh aquaculture. In general, efficient farmers are large‐scale farmers, who use a lower stocking density but a higher feeding intensity, resulting in a higher yield. On average, farmers use less labor and feed than what is optimal. To increase efficiency and reduce risk, it is recommended that more technical knowledge on optimal input use, extension service, and capital is made available to aquaculture farmers.  相似文献   

18.
Aquaculture has evolved as the fastest growing food-producing sector and developed as an important component in food security. To keep a sustainable growth pattern, health management strategies must go beyond antibiotics and chemotherapeutics, which create resistant bacteria and immunosuppression in the host. Besides development of drug resistant bacteria and pathogens, the adverse effect of antibiotics is caused by their influence on the aquatic microflora, and the retention of harmful residues in aquatic animals. On the other hand, the microbes with their unique structure and cell wall components can trigger immunity, and thus exposure plays an important role in the evolution. Microbial intervention through an environmentally friendly approach is an alternative method of health management. India is endowed with a bounty of varied climatic conditions, microbial diversity and fish fauna and aquaculture systems offering challenges in biological and environmental pursuits. Producing about 4.4% of world’s fish and ranking third in global fish production, India trades about 2.4% in global fish market with the annual export earning being over $1311 million. Use of microbes for beneficial purposes is increasingly recognized as a valuable input for sustainable and responsible aquaculture. Microbial intervention in aquaculture can be broadly water/environment based through bioaugmentation, biostimulation, biocontrol measures, or (to generate) host response through probiotics, immunostimulants, and vaccines. Also, application of molecular methods such as polymerase chain reaction (PCR) and nucleic acid techniques are making increasing inroads into aquatic microbiological research in India. This paper elucidates all these aspects of microbial intervention in aquaculture, high-lighting Indian research and accomplishments.  相似文献   

19.
The present work aims to assess the importance of settlement ponds (SP) in semi-intensive fish farms by studying benthic dynamics in an aquaculture fish farm, more specifically in the water reservoir (WR) and SP and also in production (P) and nonproduction (C) ponds during a 16-month period. In Portugal, a SP is only mandatory for intensive fish farms, and another objective of the present study is to assess the importance of these areas in semi-intensive fish farms. The WR was the area with highest diversity and evenness, as well as the higher number of exclusive taxa and taxa sensitive to organic enrichment. P and SP samples showed signs of higher disturbance levels, emphasized namely by the association of the opportunistic annelids Capitella spp. and Tubificidae. However, the benthic data from SP points to lower disturbance levels than P both due to an increase in the percentage of sensitive taxa observed in June and October 2004 and by the association of this latter sample with water reservoir samples as evidenced by canonical correspondence analysis. Moreover, a higher and increasing number of taxa when compared with the P area were also observed. Therefore, in semi-intensive fish farms, where effluents from P ponds are directly discharged to the lagoon, the potential environmental impacts would be more severe. In conclusion, the imposition of SP in semi-intensive fish farms should be considered, especially because most fish farms are located within relevant wetland areas.  相似文献   

20.
This review paper examines the structure of the EU aquaculture sector, the contribution it makes to the EU economy and the policy environment for past and future development. The primary analysis uses statistical data from the Food and Agriculture Organization of the United Nations which has been re-categorized according to species groups established by the European Aquaculture Technology and Innovation Platform (EATiP) and by culture system type using expert knowledge. Additional data sources for the analysis include the European Market Observatory for Fisheries and Aquaculture Products (EUMOFA) and the European Commission Scientific, Technical and Economic Committee for Fisheries. EU aquaculture production was 1.34 million tonnes in 2012 with a first sale value of €4.76 billion. Shellfish comprised 45 % by volume and 28 % by value; marine fish 30 % by volume and 53 % by value; and freshwater fish 25 % by volume and 19 % by value. The total production volume has actually fallen slightly from 1.4 million tonnes in 2000, whilst the value has increased significantly from 2.79 billion in 2000, mainly due to a growth in Atlantic salmon production. Five countries accounted for around 78 % of the direct output value of EU aquaculture in 2012, the UK, France, Greece, Italy and Spain. Around 50 % of the direct output value was generated using marine cage systems (28 % by volume), whilst less than 3 % of value was generated in recirculated aquaculture systems (<1.5 % by volume). Around 5 % of value was contributed by extensive to semi-intensive inland and coastal pond systems. STECF (2014) estimates there are between 14,000 and 15,000 aquaculture enterprises in the EU employing around 80,000 people, approximately 40,000 full-time equivalent (FTE). The greatest number of jobs (FTE) is provided by the freshwater pond and suspended shellfish sectors due to much lower productivity figures. This could be seen as a social benefit in rural and coastal regions, but corresponding low wages could also discourage young entrants to the industry and lead to dependency on migrant workers. Where efficiencies can be improved through capital investment there is likely to be significant scope for consolidation of ownership as can be observed in the marine fish sector. The output from aquaculture has to find a place within the wider fish and seafood market where volumes are generally inversely related to price. The potential growth of the sector is therefore constrained both in relation to the overall market and with respect to competition from substitute products. These include product from EU capture fisheries as well as imports from third countries (sourced from aquaculture and capture fisheries). Whilst interactions between individual products can be hard to demonstrate, any increase in production costs is likely to lead to lower output volumes, whilst improvements in production efficiency can lead to increased output volumes. With around 60 % of EU fish and seafood supply obtained through imports, and little prospect of increasing outputs from capture fisheries, EU policy is generally supportive of sustainable aquaculture development for reasons of food security and economic development. The underlying basis for this is maximizing the quality and health benefits of farmed products, whilst improving resource efficiency and minimizing impacts. This is expressed through funding support for research and technological development and structural funds to the fisheries and aquaculture industries. However, constraints to growth also exist in the form of regulatory barriers and costs that reduce industry competitiveness. Changing market requirements are also a factor. Prospects for growth have been assessed using the results of EATiP stakeholder workshops combined with the analysis of the sector by system type. These suggest an overall increase in production by 55 % is possible by 2030 based mainly on expansion of marine cage-based farming using larger systems in more exposed sites and similarly shellfish farming using larger-scale suspended systems. Expansion of recirculated aquaculture systems appears likely based on entrepreneurial and European policy for research and technological development activity, although constrained by currently low competitiveness.  相似文献   

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