Production Characteristics of Channel Catfish,Ictalurus punctatusStocked at Two Densities in the Partitioned Aquaculture System

Abstract

This study was conducted to determine if channel catfish could be cultured at an increased density in the Partitioned Aquaculture System (PAS) without significantly affecting performance. Channel catfish fingerlings (36.53±6.76 g; mean ±SD) were initially stocked into six 9.15 m³ sections at 3,461±317 fish per section, twice the designed carrying capacity, and fed twice daily to satiation. After 75 days, the density of three units was reduced by approximately 50% and all six units were fed for another 97 days. There was no significant difference (P > 0.05) in mean growth rate, feed conversion ratio, or production between fish grown at the low- and high-density treatments. Also, length variation (CV) and condition factors (K) were similar (P > 0.05) between fish grown at the low and high-density. Increasing density by twice the designed carrying capacity did not affect performance of channel catfish in the PAS.     

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.     

The evolution of farm management,production efficiencies,and current challenges to catfish production in the United States

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.     

Effects of inter‐country aquaculture technology diffusion rates on international shrimp market shares

Abstract

Technology innovation and diffusion in shrimp aquaculture has resulted in increased quantity and supply of shrimp to satisfy expanding consumer demand. Logistic growth curves are estimated to depict the rate of diffusion of shrimp aquaculture technology throughout the major shrimp producing countries. A time series/cross sectional model is applied to 1985–1991 and 1995–1999 production data to evaluate factors influencing shrimp production growth rates. Calculated market shares for each country indicate that operating costs, lagged shrimp price, number of hectares in production, lagged export quantity of shrimp, and market structure influence the aquaculture technological diffusion rates and shrimp produced, and suggest that countries that incorporate technologies into their production system benefit the most from increased market share.     

絮团浓度对革胡子鲇零换水养殖效果的影响

为研究絮团浓度对革胡子鲇零换水养殖效果的影响,在不额外添加有机碳源（只利用饲料中的碳）的革胡子鲇（）养殖系统中,设置了平均絮团质量浓度为561.18 mg/L和780.41 mg/L两个处理组,比较了两实验组的水质、菌群结构、鱼生长及氮利用效率。结果表明,两种浓度絮团条件下,总氨氮（total ammonia nitrogen,TAN）和亚硝酸氮（NO₂^--N）能分别维持1.84 mg/L和1.79 mg/L以下。两处理组间pH、溶解氧（dissolved oxygen,DO）、TAN、NO₂^--N、氮素利用效率及主要生长指标无显著差异（-N）浓度（822.0 mg/L）明显高于低浓度絮团组（623.33 mg/L）。高通量测序分析菌群结构结果表明,两组间门水平的菌群组成种类及优势度无显著性差异（<0.05）。两处理组中的革胡子鲇存活率分别达到（91.11±1.53）%和（94.44±2.08）%,饲料系数为（1.41±0.18）和（1.27±0.26）,特殊生长率为（2.13±0.04）%/d和（2.19±0.08）%/d,均无显著差异（>0.05）。两实验组饲料氮的利用率分别达到了72.17%和71.34%。综合以上结果认为,仅利用饲料中的碳既能维持革胡子鲇的零换水养殖且能取得较高的氮素利用效率,两种絮团浓度对革胡子鲇的生长无显著影响,高浓度絮团组中的硝化作用更明显。     

Evaluation of Diquat as a Potential Algicide for Controlling the Musty-Odor-Producing Cyanobacterium,Oscillatoria perornata,in Catfish Aquaculture Ponds

ABSTRACT

The synthetic herbicide diquat was applied to a catfish aquaculture pond containing a heavy bloom of the cyanobacterium Oscillatoria perornata(a major contributor to musty off-flavor in farm-raised catfish) in order to determine the effectiveness of diquat as a selective algicide to prevent musty off-flavor in cultured catfish. Levels of the musty-odor compound 2-methylisoborneol (MIB) and numbers of O. perornata were monitored. Results indicate that diquat is not useful as an algicide for controlling O. perornata in catfish aquaculture ponds, despite its usefulness in controlling other aquatic weeds.     

Viable aquaculture development in the U.S. affiliated islands‐lessons from giant clam and sponge farming

Abstract

The Center for Tropical and Subtropical Aquaculture (CTSA), which is funded by the U. S. Department of Agriculture as one of its Regional Aquaculture Centers, has assisted giant clam and sponge fanning technology development and technology transfer within the region since 1989. Six species of giant clam and one species of bath sponge can currently be commercially produced in the region. After over 12 years of intensive effort by CTSA to develop and transfer technology, the production of giant clam and bath sponges has yet to make any significant contribution to the local economy.

By self‐evaluation of our efforts and the continuing efforts of others, this paper provides possible solutions on aquaculture development related factors, which include biological, technological, environmental, and socioeconomic. Recommendations are made on viable aquaculture development in the region based on our experiences. Amongst other factors, the government's commitment to aquaculture and the resulting actions are vital. Farming technology for giant clams and sponges are also briefly reviewed.     

A survey of aquaculture production economics and management

Abstract

The literature on production economics and management of fish culture has grown as aquaculture has matured as a commercial industry. Salmon, catfish, shrimp and trout are the focus of this literature survey as a reflection of the volume of research that has been completed on these species and their importance in US production and world trade. In addition, a discussion of low resource production systems is included that is dominated by tilapia and carp culture systems. A brief overview of the principles of aquaculture production economics and management is presented followed by a review of economic studies.     

A review of production frontier analysis for aquaculture management

Abstract

This paper examines recent advances in production economics with special reference to efficiency measurement using production frontiers and its implications for aquaculture management. Compared with agriculture and other industries, the use of production frontiers in aquaculture is still very limited. However, in recent years several frontier applications in aquaculture have appeared in the literature, suggesting potential applications of these techniques in aquaculture. A synopsis of stochastic frontier production function model and data envelopment analysis (DEA), the two most popular approaches to efficiency measurement, is presented, followed by a review of recent frontier studies in shrimp, carp and tilapia production. The paper concludes with a brief discussion of future development and prospects of frontier applications for aquaculture management.     

Sustainable commercial aquaculture: A survey of administrative procedures and legal frameworks

Abstract

Commercial aquaculture which, for this paper, is defined as the rearing of aquatic organisms that is profit oriented and primarily by the private sector, contributes to food security, directly by producing food fish, and indirectly by generating employment, and thus, income for the purchase of food. In addition, commercial aquaculture can be sustainable because it depends on private, rather than public funds that are usually lacking or scarce. The paper describes some enabling policies that are conducive to the promotion of commercial aquaculture. In particular it focuses on administrative and legal frameworks. The paper concludes that development of aquaculture can be enhanced by legislation specific to the sector rather than relying on general fisheries legislation; such a legislative framework (particularly for land‐based aquaculture) would resemble that of agriculture. Regulations require expensive and time‐consuming monitoring and enforcement; they should focus on environmental protection and a sustainable industry.     

Mine Water Aquaculture as an Economic Development Strategy

Abstract

This study involves a comprehensive economic analysis of mine water aquaculture. First, the costs and benefits are quantified using standard enterprise budgeting and feasibility techniques. Next, a price analysis is conducted to determine the underlying probability distribution and generate confidence intervals for use in planning purposes. Then, the relationships between mine sites and unemployment, and mine sites and tourism, respectively, are illustrated using a spatial analysis. Finally, the potential economic development impacts of growth in the aquaculture industry on statewide output, income, and employment are estimated. The results have implications for entrepreneurs and the aquaculture and coal industries in Appalachia and other parts of the US where coal mining can be linked to fish farming, water conservation, and recreation.     

Risk efficient juvenile haddock production systems: An ex‐ante recursive stochastic approach

Abstract

The risk efficient live feed system for juvenile haddock production is derived through recursive ex‐ante stochastic cost estimation. Four alternative feeding technologies are simulated to capture the economic costs associated with live feed and juvenile production and scale economies are investigated by simulating three production levels. Using Monte Carlo simulation techniques, multivariate stochastic cost functions are derived in a time‐dependent recursive production model. With the current technologies and price levels, land‐based juvenile haddock production is viable. The marginal impact, in terms of cost‐savings, to additional research on optimal feeding periods will be minimal. On the other hand, the high opportunity cost of capital used in aquaculture production, due to numerous perceived risk premia, may pose a more immediate constraint for capital formation and industry development.     

Economics of cage culture in Puerto Rico

Abstract

Puerto Rico has been faced with a decline of fish stocks similar to other parts of the world. Offshore cage aquaculture might be an answer to this problem although there are many unanswered questions. This paper describes a project in Puerto Rico that assessed the economics of offshore cage culture for aquaculture. The first cage was placed in the water in February 2002 with a second one to follow shortly thereafter.     

The economic impact of feeding restrictions on US catfish, Ictalurus punctatus (Rafinesque), aqafuaculture operations

Increasing stocking densities in catfish, Ictalurus punctatus (Rafinesque), aquaculture are making maintenance of water quality a crucial element of production strategy. A bioeconomic simulation model for catfish has been adapted to assess alternative feeding restriction management strategies for US catfish aquaculture operations. The current model includes five decision variables: feeding rate, diet quality, stocking weight, stocking date, and length of growing season. The growth model follows a bioenergetics approach, where the balance between energy intake and energy expenditure determines fish growth. The purpose of this analysis was to simulate changes in production practices resulting from water quality restrictions. Model simulations indicate that restricting maximum daily feeding allowance to maintain higher water quality will actually increase feed requirements to reach a harvestable fish size. In addition, as producers increasingly attempt to spread harvests throughout the year, both for their own cash flow needs and the consistent supply requirements of processors, restricting daily feed allowance will make summer harvests particularly difficult.     

Economics of risk and uncertainty of alternative water exchange and aeration rates in semi‐intensive shrimp culture systems

Abstract

Reducing water exchange in shrimp aquaculture to minimize discharge of pollutants is a search for sustainability. In desert regions, like most of northwest Mexico, low water exchange must be complemented with artificial aeration to compensate for low levels of oxygen in warm and highly saline water. The economic yield of a low‐water‐exchange production system is compared against yield from a typical water‐exchange‐without‐aeration system for Penaeus vannamei culture. The difference between two systems is centered on pumping and aeration rates for a 100 ha semi‐intensive farm in northwest Mexico.

A bioeconomic model was built to compare the systems. Risk analysis is adopted to account for uncertainty of seed price, shrimp growth rate, survival rate, and shrimp prices.

The typical system was slightly more profitable than the low‐water‐exchange, aerated system. The latter used less electricity than the former in all of the three mortality‐rate scenarios. However, the difference in profitability is so small that for practical purposes both production systems provide similar economic yield. For a typical system, the probability of reaching a positive net present value (NPV) is high, therefore under the assumed risks, a 100 ha semi‐intensive shrimp farm in northwest Mexico is a good investment choice.     

Life cycle assessment of aquaculture systems: Does burden shifting occur with an increase in production intensity?

Life cycle assessment (LCA), a tool used to assess the environmental impacts of products and processes, has been used to evaluate a range of aquaculture systems. Eighteen LCA studies were reviewed which included assessments of recirculating aquaculture systems (RAS), flow-through systems, net cages, and pond systems. This review considered the potential to mitigate environmental burdens with a movement from extensive to intensive aquaculture systems. Due to the diversity in study results, specific processes (feed, energy, and infrastructure) and specific impact categories (land use, water use, and eutrophication potential) were analyzed in-depth. The comparative analysis indicated there was a possible shift from local to global impacts with a progression from extensive to intensive systems, if mitigation strategies were not performed. The shift was partially due to increased electricity requirements but also varied with electricity source. The impacts from infrastructure were less than 13 % of the environmental impact and considered negligible. For feed, the environmental impacts were typically more dependent on feed conversion ratio (FCR) than the type of system. Feed also contributed to over 50 % of the impacts on land use, second only to energy carriers. The analysis of water use indicated intensive recirculating systems efficiently reduce water use as compared to extensive systems; however, at present, studies have only considered direct water use and future work is required that incorporates indirect and consumptive water use. Alternative aquaculture systems that can improve the total nutrient uptake and production yield per material and energy based input, thereby reducing the overall emissions per unit of feed, should be further investigated to optimize the overall of aquaculture systems, considering both global and local environmental impacts. While LCA can be a valuable tool to evaluate trade-offs in system designs, the results are often location and species specific. Therefore, it is critical to consider both of these criteria in conjunction with LCA results when developing aquaculture systems.     

Green grow the fishes‐oh? Environmental attributes in marketing aquaculture products

Abstract

The rise of aquaculture production in the last two decades has had a notable impact on many of the world's markets, sometimes supplementing or replacing existing capture fishery products, developing new market opportunities through improved availability, novel products and/or improved market chain efficiency. Meanwhile consumers have also become increasingly aware of environmental issues and associations with the products they consume; within this broader trend, the practices and possible impacts of aquaculture have justifiably or otherwise been subject to particular scrutiny and sometimes negative comment. Future opportunities and directions for growth and development of aquaculture may become increasingly driven by market perceptions of environmental attributes and, associated with this, the ways in which aquaculture processes and products are presented. This paper reviews the relevant issues of environmental attributes, explores the ways in which these may interact with future production and market trends and suggests critical emerging factors for the aquaculture sector.     

New organizational forms within the aquaculture industry: The fish‐farming enterprise as a ‘virtual’ organization

Abstract

The international aquaculture industry is characterized by a global integration process with increasing competition across borders and continents. The rapid development of technology, the extended market rivalry due to new firm entries, and the elevation of quality standards in the international seafood market place a heavy strain on the strategy development process of aquaculture enterprises. In this article, we focus on the ties between strategic positioning in the market and the organizational configuration of the firm. The virtual organization is introduced as an organizational form for a dynamic fish‐farming enterprise. A virtual organization is characterized by flexible borders, emphasis on external cooperative relations and networks instead of ownership integration, and norm‐based relational contracts as focal governance mechanism. The results from an in‐depth, longitudinal study of a Norwegian fish farming enterprise are presented.     

Comparative economic performance and carbon footprint of two farming models for producing Atlantic salmon (Salmo salar): Land-based closed containment system in freshwater and open net pen in seawater

Ocean net pen production of Atlantic salmon is approaching 2 million metric tons (MT) annually and has proven to be cost- and energy-efficient. Recently, with technology improvements, freshwater aquaculture of Atlantic salmon from eggs to harvestable size of 4–5 kg in land-based closed containment (LBCC) water recirculating aquaculture systems (RAS) has been demonstrated as a viable production technology. Land-based, closed containment water recirculating aquaculture systems technology offers the ability to fully control the rearing environment and provides flexibility in locating a production facility close to the market and on sites where cost of land and power are competitive. This flexibility offers distinct advantages over Atlantic salmon produced in open net pen systems, which is dependent on access to suitable coastal waters and a relatively long transport distance to supply the US market. Consequently, in this paper we present an analysis of the investment needed, the production cost, the profitability and the carbon footprint of producing 3300 MT of head-on gutted (HOG) Atlantic salmon from eggs to US market (wholesale) using two different production systems—LBCC-RAS technology and open net pen (ONP) technology using enterprise budget analysis and carbon footprint with the LCA method. In our analysis we compare the traditional open net pen production system in Norway and a model freshwater LBCC-RAS facility in the US. The model ONP is small compared to the most ONP systems in Norway, but the LBCC-RAS is large compared to any existing LBCC-RAS for Atlantic salmon. The results need to be interpreted with this in mind. Results of the financial analysis indicate that the total production costs for two systems are relatively similar, with LBCC-RAS only 10% higher than the ONP system on a head-on gutted basis (5.60 US$/kg versus 5.08 US$/kg, respectively). Without interest and depreciation, the two production systems have an almost equal operating cost (4.30 US$/kg for ONP versus 4.37 US$/kg for LBCC-RAS). Capital costs of the two systems are not similar for the same 3300 MT of head-on gutted salmon. The capital cost of the LBCC-RAS model system is approximately 54,000,000 US$ and the capital cost of the ONP system is approximately 30,000,000 US$, a difference of 80%. However, the LBCC-RAS model system selling salmon at a 30% price premium is comparatively as profitable as the ONP model system (profit margin of 18% versus 24%, respectively), even though its 15-year net present value is negative and its return on investment is lower than ONP system (9% versus 18%, respectively). The results of the carbon footprint analysis confirmed that production of feed is the dominating climate aspect for both production methods, but also showed that energy source and transport methods are important. It was shown that fresh salmon produced in LBCC-RAS systems close to a US market that use an average US electricity mix have a much lower carbon footprint than fresh salmon produced in Norway in ONP systems shipped to the same market by airfreight, 7.41 versus 15.22 kg CO₂eq/kg salmon HOG, respectively. When comparing the carbon footprint of production-only, the LBCC-RAS-produced salmon has a carbon footprint that is double that of the ONP-produced salmon, 7.01 versus 3.39 kg CO₂eq/kg salmon live-weight, respectively.