Technical efficiency of carp production in India: a stochastic frontier production function analysis

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.     

Technical efficiency analysis of milkfish (Chanos chanos) production in Taiwan—an application of the stochastic frontier production function

Milkfish has been farmed in Taiwan for over 300 years. Faced with limited land resources, a labor shortage, decreasing demand, and growth of imported fisheries products, the industry is looking at the problem of how to maintain a sustainable and efficient production. This study specifies a stochastic production frontier function to estimate potential milkfish farm output and efficiency by using 1997–1999 data from a survey of 433 aquaculture milkfish farms. Both Translog and Cobb–Douglas frontier production models are estimated using the maximum likelihood estimation method. Empirical results show that the Translog stochastic production function model fits the data better and that milkfish farming in Taiwan exhibits diminishing returns to scale. We also compare estimated maximum potential milkfish production per hectare under various pond conditions to provide managers with information about how to boost efficiency. In addition, this study estimates substitution elasticities and complementarity of input factors for milkfish farms to provide helpful information for milkfish farmers on how to reallocate input resources and help raise milkfish productivity through improvements in technical efficiency.     

Economic efficiency and optimum stocking densities in fish polyculture: an application of data envelopment analysis (DEA) to Chinese fish farms

Polyculture is commonly practiced in pond aquaculture where several fish species are reared together, creating a multi-output production structure. This study applied a nonparametric data envelopment analysis (DEA) technique for multiple outputs to: (1) measure economic or ‘revenue' efficiency and its technical and allocative components for a sample of Chinese polyculture fish farms; and (2) derive the optimum stocking densities for different fish species. The mean economic efficiency was estimated to be 0.74. Technical inefficiencies accounted for most of the production inefficiencies in Chinese fish farms. On average, farmers should increase grass carp and decrease black carp stocking rates. Smaller farms and those from the developed regions were found to be relatively more technically and economically efficient.     

Profitability and technical efficiency of aquaculture systems in pampaanga,philippines

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.     

Technical efficiency of carp production in Pakistan

Abstract

The main objective of this study is to examine technical efficiency and its determinants in carp pond culture in Pakistan. A stochastic production frontier involving the model for technical inefficiency effects is applied separately to the samples of semi‐intensive/intensive and extensive carp producers. The mean technical efficiencies for semi‐intensive/intensive and extensive farms were 0.673 and 0.561, respectively. By operating at full technical efficiency the semi‐intensive/intensive farms could, on average, increase their production from 3.0 to 4.5 Mt/ha and the extensive farms from 2.6 to 4.6 Mt/ha. Much of these efficiency gains would come from the improvement in fish, water and feed monitoring and management. Besides improving technical efficiency, potential also exists for raising carp productivity through increased intensification and technological progress. However, the realization of these potentials will depend on continuous government support for adequate provision of inputs, market and infrastructure, technology transfer and development and extension and credit services to carp farmers.     

Technical efficiency of carp production in Nepal: An application of stochastic frontier production function approach*

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.     

主养草鱼池塘三种混养模式鱼类生长和效益的比较

为进一步提高我国广大池塘养鱼的产品质量、经济效益和改善其生态环境。本试验在武汉新洲973项目实验基地9个陆基鱼池中进行了三种不同混养模式鱼类生长和效益的比较研究,每种模式设3个重复。模式Ⅰ中放养草鱼、鲢、鳙和高背鲫;模式Ⅱ中放养草鱼、鲢、鳙、匙吻鲟和高背鲫;模式Ⅲ中放养草鱼、鲢和高背鲫。 结果表明：通过122d的养殖试验,模式Ⅱ中草鱼的生长不仅显著高于模式Ⅰ和模式Ⅲ（P<0.05）,而且其经济效益模式Ⅱ同样高于模式Ⅰ和模式Ⅲ。     

Asian carp farming systems: towards a typology and increased resource use efficiency

Resource use efficiency in Asian carp farming systems is analysed based on a survey of 2493 farms of nine countries. Multivariate classification of farms by intensity and diversity identified six farm types: four types of specialized aquaculture farms at different levels of intensity, and two types of integrated agriculture–aquaculture systems. Pond‐based, specialized semi‐extensive systems (using mainly inorganic fertilizers and feeds of off‐farm origin), and integrated semi‐intensive systems (using feeds and fertilizer of both on and off‐farm origin) are by far the most common types, accounting for 59% and 27% of all farms respectively. Specialized semi‐extensive systems also show the highest protein and nutrient (N and P) use efficiencies, and among the highest labour use efficiency. Super‐intensive cage farms are less efficient in nutrient and labour use, but provide very high returns to land and capital investment. On average, the aquaculture components of integrated agriculture– aquaculture systems are less nutrient, land, and labour efficient than specialized semi‐extensive systems. Integrated semi‐extensive systems (using organic fertilizers of on‐farm origin) are particularly inefficient across all indicators. Hence in practice, gains in overall resource use efficiency through on‐farm integration with agricultural production are constrained by the relative inefficiency of the aquaculture subsystems on integrated farms. Although such systems can likely be improved, integration as such is not a panacea to increasing resource use efficiency. Wide variation in resource use efficiency within all systems indicates potential for substantial efficiency gains through improved management regardless of the fundamental choice of system.     

不同鲤养殖模式生物絮团系统中鱼体的生长及水质

为了探明不同鲤养殖模式生物絮团系统中鱼体的生长及水质变化情况。采用陆基围隔法,分别设置了鲤单养、鲤+鳙二元混养及鲤+鳙+鲢三元混养3种鲤养殖模式,每种模式设3个重复,测定了鲤不同养殖模式下鱼体的生长及水质参数,实验共进行90 d。结果显示,与单养模式相比,二元混养和三元混养鲤的存活率和鱼体蛋白质效率均显著偏高,而其总饲料系数则显著偏低。3种养殖模式中鲤肌肉的水分和粗脂肪含量相互之间差异均不显著,三元混养模式鲤肌肉的粗蛋白和灰分含量均显著高于单养模式。在3种养殖模式生物絮团系统中,生物絮团形成量与水温之间在19.3~28.5°C范围内呈显著的正相关。整个实验过程中,二元混养和三元混养水体的总氨氮、亚硝酸态氮、总无机氮、正磷酸盐及总悬浮颗粒物含量均低于单养模式,而硝酸态氮、总碱度、有机悬浮颗粒物及叶绿素a含量均高于单养模式,除叶绿素a之外,其余水质参数相互之间差异均不显著。研究表明,与传统的混养系统相似,在生物絮团养殖系统中,符合生物学原则的混养模式同样能够有效发挥养殖系统的生态功能,提高养殖效率。     

Measuring technical,allocative and cost efficiencies of seabass and seabream farms in Greece

Abstract

A stochastic Cobb‐Douglas production frontier is used to provide estimates of output‐oriented technical efficiency, input‐oriented technical efficiency, input allocative efficiency and cost efficiency for a sample of seabass and seabream farms in Greece. Mean output‐oriented technical efficiency is estimated at 78.5%, input‐oriented technical efficiency at 73.6%, input allocative efficiency at 79.2%, and cost efficiency at 58.2%. Considering the sources of efficiency differentials among fish farms, it is evidence from the empirical results that large farms tend to achieve higher (technical and allocative) efficiency scores; specialization in either seabass or seabream affects positively technical and cost, but not allocative, efficiency; and utilization of skilled labor seems to have a positive impact only on technical efficiency.     

Effects of modified pond management on limnological parameters in small‐scale aquaculture ponds in mountainous Northern Vietnam

In mountainous Northern Vietnam, traditional pond aquaculture is part of the integrated farming activity contributing to food safety and to income generation for small‐scale farmers of ethnic minorities. Traditional pond management consists of a polyculture of macro‐herbivorous grass carp with 3–5 other fish species that are cultured in small ponds with constant water flow through. The main limitations to production are species‐specific mass mortalities of grass carp, a poor feed base especially for all species but grass carp, and poor water quality. In this study, we compared the traditional pond management to a semi‐intensive pond management that was based on the traditional management system but included changes designed by researchers to increase fish production. The modifications consisted of water inflow control, supplemental fertilization and feeding, and a polyculture dominated by common carp. The changes in management significantly reduced the turbidity and increased oxygen supply, as well as the natural food base within the pond. These changes in pond management provide farmers with the possibility to improve their pond aquaculture scheme and overcome previous limitations.     

Technical efficiency of carp pond culture in South Asia: An application of a stochastic meta‐production frontier model

Abstract

A stochastic meta‐production frontier model is estimated to examine the inter‐country differences in levels of technical efficiency of semi‐intensive/intensive and extensive carp pond culture systems among the major carp producing countries in South Asia, namely India, Bangladesh, Pakistan, and Nepal. The mean technical efficiencies for semi‐intensive/intensive farms vary from 0.68 for Nepal to 0.79 for India, with an overall average of 0.75 and those for extensive farms vary from 0.48 for Bangladesh to 0.62 for Pakistan, with an overall mean of 0.57. Differences in efficiency levels are explained in terms of various farm‐specific and country‐specific factors by estimating a model for technical inefficiency effects. The adoption of recommended fish, water, and feed management practices is found to be critical for improved performance of carp producers. For each country, the study also compares the efficiency scores based on its own production frontier with those obtained from the meta‐production frontier.     

Ecological intensification for feeding rohu Labeo rohita (Hamilton, 1822): A review and proposed steps towards an efficient resource fishery

Labeo rohita (rohu) is a commercially popular Indian major carp species in polyculture fish farming system. It feeds mainly on plankton. The adults of rohu have a strong positive selection for phytoplankton, whereas the fingerlings have a strong positive selection for both zooplanktonic and smaller phytoplanktonic sources. Conversely, adults of rohu exhibit a strong negative selection for all zooplanktonic sources and a positive selection for most phytoplanktonic sources. In periphytic environments, the fish grow better feeding on the sub‐periphytic zone in proximity to the substrate. We conclude that rohu is an excellent aquaculture candidate, thanks to its ability to explore natural resources (plankton and periphyton) and transform them to fish biomass in polyculture practice. In contrast to over‐reliance on artificial feed, translation of natural resources for exploration by rohu could be the next step for sustainable carp‐based polyculture practice.     

罗氏沼虾与三角帆蚌、鲢和鳙混养模式优化

研究了罗氏沼虾、三角帆蚌、鲢和鳙不同混养系统的养殖产量、饲料系数、增长率、总氮(TN)/总磷(TP)利用率和综合养殖效果,以期获得最优养殖模式。采用基于陆基围隔的比较实验方法,设6个实验组,分别为罗氏沼虾单养(G),罗氏沼虾与三角帆蚌二元混养(GH2)、罗氏沼虾、鲢和鳙三元混养(GSB),罗氏沼虾、鲢、鳙和三角帆蚌按照不同密度放养的四元混养(GSBH1、GSBH2和GSBH3),各实验组设置4个重复。结果表明:GSBH2组罗氏沼虾产量最高[(14.71±0.33)kg/32 m2],显著高于G组[(12.44±0.60)kg/32 m2,P0.01];GSBH1组饲料系数最低(1.43±0.04);GSBH1组增重率最高(4.66%±0.12%),G组最低(3.80%±0.23%);TN平均相对利用率在(0.92±0.09)~(1.60±0.23)之间,GSB组最高,G组最低;TP平均相对利用率为(0.23±0.03)~(1.46±0.32),GSBH3组最高,G组最低;综合养殖效果指数在(0.91±0.02)~(1.25±0.05)之间,GSB组最高,GSBH1组次之,G组最低,且三元、四元混养组显著大于G组和GH2组(P0.05)。研究表明,混养组能显著提高罗氏沼虾养殖的经济效益和生态效益。     

A Technical Efficiency Analysis of Hawaii's Aquaculture Industry

This study examines the technical efficiency (TE) of aquaculture farms in Hawaii. Policy makers and industry participants interested in assessing the economic outlook of aquaculture production not only have to assess measures of profitability and financial health, but also measures of production efficiency. We estimate the TE of the state's aquafarms with a data envelopment analysis (DEA) model. Using data from the US Census of Agriculture, we examine TE measures of the population of Hawaii's aquafarms across different types of farms and over time. The results show that only 12% of the farms in 2007 may be classified as efficient, with a steady decline in efficiency over time. We find TE was related to the size of farm, full‐time farms were significantly more efficient than part‐time farms and that the average excess real inputs for land and labor have slightly fallen over time. The sub‐sector analysis revealed a strong variation of TE across different type of farms. With few farms operating on the frontier, the findings of this study suggest that the majority of the farms could improve their TE.     

Deficient melanin production contributes to the absence of melanophores in early development of red carp

Red carp and red crucian carp are ornamental fish with a red body color. Unlike in red crucian carp, no melanophores are observed in red carp embryos or larvae. To explore the roles of the mitfa gene in body color formation in red carp, we investigated the structural characteristics and physicochemical properties of the mitfa gene in 16 kinds of fish. The mitfa amino acid sequence similarity between red carp and red crucian carp was 95.6%, and this was 91.5% similar between carp and zebrafish. Compared with red crucian carp, red carp showed lower tyrp1 messenger ribonucleic acid (mRNA) expression but similar mitfa mRNA expression in the body pigment stage of the embryo. Moreover, mitfa⁺ cells as well as melanocytes could be observed in cultured embryo cells derived from red carp and red crucian carp. Our data show that the absence of melanophores in red carp is not the result of mitfa gene deletion or mutation, increasing our understanding of the molecular and genetic mechanisms of coloration in cyprinid fish.     

AN EMPIRICAL TYPOLOGY OF BRACKISH-WATER POND AQUACULTURE SYSTEMS IN THE PHILIPPINES: A TOOL TO AID COMPARATIVE STUDY IN THE SECTOR

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.     

Growth and reproduction of threatened native crucian carp Carassius carassius in small ponds of Epping Forest,south‐east England

• 1. The crucian carp Carassius carassius is a species of cyprinid fish native to south‐east England, but few studies exist on its growth and reproduction in England, and the species is threatened by introductions of its Asiatic congener, goldfish Carassius auratus. To increase knowledge of the crucian carp as a means of aiding its conservation, the present study assesses the growth (back‐calculated length at age, body condition) and reproduction (fecundity, egg size, length and age at maturity) of crucian carp in small ponds of Epping Forest (north‐east London, England).
• 2. Evaluation of growth and reproduction data with published data for populations from northern Europe (i.e. latitude ?50°) suggest that growth is very variable, even within the same area, and that data on reproductive indices, in particular length and age at maturity, are scarce. In England, the length at age trajectory of crucian carp living in sympatry with feral goldfish Carassius auratus did not differ significantly from allopatric crucian carp populations, but crucian carp body condition and relative fecundity (eggs per body weight) were highest, and mean age and standard length at maturity were lowest in sympatry with goldfish.
• 3. These data suggest that somatic growth and reproductive output may be maximized in crucian carp when confronted by coexistence with feral goldfish. However, the potential impact of goldfish introductions on crucian carp growth and reproduction requires further study, involving a much larger number of crucian carp populations, both in allopatry and sympatry with feral goldfish populations.

© Crown copyright 2009. Reproduced with the permission of Her Majesty's stationery Office. Published by John Wiley & Sons, Ltd.     

Introduction of jundia Rhamdia quelen (Quoy & Gaimard) and Nile tilapia Oreochromis niloticus (Linnaeus) increases the productivity of carp polyculture in southern Brazil

Fish polyculture is based on the assumption that each species has its own feeding niche and may increase the maximum standing crop of a pond by exploring a wider range of available food and ecological niches. In order to identify the better species ratio and to introduce jundia (JN) (Rhamdia quelen Quoy & Gaimard) and Nile tilapia (NT) (Oreochromis niloticus Linnaeus) in to the carp polyculture practiced in South Brazil, a 162‐day experiment was conducted, in 12 250‐m² earthen ponds (1.2 m deep). Treatment I (T‐I) contained 35% common carp, Cyprinus carpio (L.) (CC); 35% grass carp, Ctenopharyngodon idella Valenciennes (GC); 15% silver carp, Hypophthalmichthys molitrix Valenciennes (SC); and 15% bighead carp, Aristichthys nobilis Richardson (BC). Treatment II (T‐II) consisted of three ponds stocked at the following ratio: 17.5% CC, 35% GC, 15% SC, 15% BC and 17.5% JN. Treatment III (T‐III) consisted of three ponds with 35% CC, 35% GC, 7.5% SC, 7.5% BC and 15% NT. Treatment IV (T‐IV) consisted of three ponds with 17.5% CC, 35% GC, 7.5% SC, 7.5% BC%, 17.5% JN and 15% NT. No significant correlation was found between the treatments with different species ratio and water quality parameters. The final weight of different species, in different treatments, was statistically different. The major result was the clear positive effect on growth parameters observed by the introduction of JN and/or NT in to the carp polyculture. The yield per hectare was 2083.33±183 kg ha^?1 for polyculture with carp species; 2476.67±139.88 kg ha^?1 following the introduction of JN only; 2801.67±111.42 kg ha^?1 for isolated introduction of NT; and 2506.67±422.31 kg ha^?1 for simultaneous introduction of JN and NT. The introduction of JN and/or NT had a positive effect on growth parameters when compared with carp‐only polyculture. The reduction in CC ratio also had a positive effect on growth parameters.