The effects of water temperature in aquaculture management (original) (raw)
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Aquaculture, 2016
Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site. cage farming system depends on temperature. This result is important for the development of breeding objectives maximizing economic return in fish breeding programs. Statement of relevance The economic impact of improving growth rate in sea cage farming system depends on temperature. This result is important for the development of breeding objectives maximizing economic return in fish breeding programs. Highlights ► First study to calculate the economic value of growth rate in different temperature conditions in the Mediterranean ► When the average temperature is 18 °C, the economic impact of growth rate is null. ► When the average temperature is 19.5 °C or 21 °C, the economic impact of growth rate is positive. ► First study to show the importance of variation in ambient seawater temperatures for breeding programs in fish
Optimum management and environmental protection in the aquaculture industry
Ecological Economics, 2008
The sustainability of the aquaculture industry has recently been the object of social and scientific debate, due to the contamination caused by the culture to the surrounding environment. As a contribution to the debate, this paper analyses the effect of adopting a Pigovian tax to internalise the environmental costs on the optimal management of farms. To do so, we make use of dynamic stochastic models of fish growth and contamination diffusion. Farms can also implement some measures to abate pollution, which are divided into two types: those applied continuously ("managerial" measures) and those once in a culture cycle ("structural" measures). The results reveal that the tax imposition lowers the optimum size in the farm. The type of abatement strategy plays a central role in the determination of the optimum harvest size. A need for caution in internalisation policies is emphasized, as negative consequences could arise in certain cases, putting the farms' survival at risk.
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Journal of environmental management, 2015
The evaluation of the environmental impact of aquaculture installations is nowadays a common social demand in many countries. The usual scientific approach to this question has been to assess the outcome from an ecological perspective, focussing on the effects produced on benthos or the water column and interactions with marine flora and fauna. In this paper, a bioeconomic model is developed to extend this traditional approach, to determine both the amount of total settled matter, its dispersion on the ocean floor and impacts on the marine ecosystem, while also taking into account other social considerations such as discounted net profits and investment returns. The model was applied to the case of off-shore gilthead seabream production in a coastal area of the Canary Isles archipelago, where the tidal current is predominant. Cage emissions and the degree of degradation of seagrass meadows on the seabed were taken as ecological impact indicators, while the net present value (NPV) fo...
Optimization of aquaculture systems in Spain
Energy Conversion and Management, 1997
An analysis of present heat production systems, using fossil fuel combustion, employed for sea water heating in Spanish hatcheries is given in this paper and compared to a technical solution based on the employment of a heat pump. Price per unit of produced energy is calculated for each system using liquid and gaseous fuels, and then these prices are compared to the price obtained for a heat pump. The heat pump system is also compared, from the point of view of its precision in maintaining temperatures, to the systems used at the present. A project prototype for thermal conditioning and temperature control in aquaculture rearing tanks is described. The waste heat of the return water is recovered: first, by a static recoverer and second, by a recoverer connected to the evaporator of a refrigeration unit. The system should be used in such a way that economic benefits are obtained from its two heat sources of the frigorific system in simultaneous production of warm and chilled sea water. 0 1997 Elsevier Science Ltd Aquaculture Fuels Heat recoverer Heat pump Heat cost I. . n = Recoverers; points of cycle 879 880 IZQUIERDO and CARRILLO: AQUACULTURE SYSTEMS IN SPAIN
A Methodological Note for the Development of Integrated Aquaculture Production Models
Aquaculture production can yield significant economic, social, and environmental effects. These exceed the financial costs and benefits aquaculture producers are faced with. We propose a methodology for the development of integrated production models that allow for the inclusion of the socioeconomic and environmental effects of aquaculture into the production management. The methodology develops on a Social Cost-Benefit Analysis context and it includes three parts: (i) environmental, that captures the interactions of aquaculture with the environment, (ii) economic, that makes provision for the incorporation of economic determinants in the production models and (iii) social, that introduces the social preferences to the production and management process. Alternatives to address data availability issues are also discussed. The methodology extends the assessment of the costs and benefits of aquaculture beyond pure financial metrics and beyond the quantification of private costs and benefits. It can also support the development of integrated models of aquaculture production that take into consideration both the private and the social costs and benefits associated with externalities and effects not appropriately captured by market mechanisms. The methodology can support aquaculture management and policies targeting sustainable and efficient aquaculture production and financing from an economic, financial, social, and environmental point of view.
Optimal feeding and harvest time for fish with weight-dependent prices
Marine resource economics, 1998
Like agriculture, decisions regarding aquacultural production are complex. In addition to controlling harvest, feeding schedules, and culling rates, one must consider a number of practical considerations that may supersede other factors in economic importance. Among these pragmatic considerations are unusual aspects of the market price for fish. Fish markets provide premiums for larger-sized fish, and the premiums are often piecewise linear. This paper extends existing research by demonstrating general solutions for optimal feeding schedules and harvesting time under conditions of piecewise-continuous, weight-dependent prices. The solutions are characterized by idiosyncratic responses to marginal changes in exogenous parameters. For instance, a 1% decline in the interest rate can induce a 70% increase in the optimal weight. In general, as the interest rate decreases, optimal harvest weight and harvest time increase in a stepwise, nonlinear fashion. . Comments from Lars Olson, Camilo Sarmiento, and two anonymous reviewers are gratefully acknowledged. We also wish to thank Yana Christou, Demosthenes Ioannou, and his hospitable family for providing the sea bream production data. Funding for the project was provided by the Maryland Agricultural Experiment Station. 1 In this paper, we focus on the economics of open-system aquaculture. An open-system implies that not all of the biological parameters (i.e., water temperature, biological oxygen demand, etc.) affecting fish growth are controlled by the farmer. The following papers provide an economic analysis of closed system aquaculture: ; ). 2 Heaps (1993 followed up on the optimal control aquaculture model of Arnason. First, he derived a number of results concerning the effect of changes in various model parameters on the characteristics of the final harvest. Second, he extended the original model by allowing for density-dependent growth.
Aquaculture, 2014
Offshore production system is predicted to increase in the near future driven by the lack of coastal space and lower environmental impacts. The aim of this paper has been to evaluate the economic performance of offshore production system respect to inshore one, by comparing net present value (NPV), discounted payback time (DPBT) and internal rate of return (IRR) of two Italian mariculture farms that produce European sea bass. Results showed a better economic profitability of offshore farm, even if sensitivity analysis revealed that financial indicators of both aquaculture production systems have been very sensitive to market condition changes. So, offshore production system could represent an opportunity for fish farmers to increase their profitability, obtaining a more sustainable production and avoiding possible conflicts with other human activities in coastal areas.
A dynamic ecological–economic modeling approach for aquaculture management
Ecological Economics, 2009
This paper presents a Modeling Approach to Resource economics decision-maKing in EcoaquaculTure (MARKET model). The MARKET model was developed as a scenario-testing tool to provide insights on the ecological and economic interactions, which is a critical issue for sustainable aquaculture management. As a case study, the model was applied to simulate shellfish production in an embayment located in the East China Sea. A set of scenarios was used to compare the model outputs with expected trends and to test its capability to simulate relevant management scenarios. The comparison of simulated scenarios indicates that the MARKET model outputs followed the expected trends regarding both standard economic theory for consumption and production, and ecological economic theory. In all the scenarios we tested the area available for aquaculture was found to impose a limitation on production before it became less profitable to expand production. As such, in this case study, the production in the long run does not meet increasing demand. Reduction of the maximum cultivation area was simulated in one of the scenarios as an example of a conservation measure. As expected there was a reduction of the net profit of the farmers compared with the standard simulation. On the other hand, this scenario combined with an increase in price growth rate simulates a compensatory measure that led to a net profit in the same range as observed in the standard simulation. Overall the MARKET model provides insights and raises questions useful for the implementation of an ecosystem approach to aquaculture. Further developments include the simulation of waste generated by cultivated species in order to better support sustainable management objectives.
Economic analysis of rural and artisanal aquaculture in Ecuador
2009
Three different types of culture and conditions were tested to determine the profitability of Rural and Artisanal Aquaculture Project in Ecuador: monoculture of the freshwater fish named locally cachama (Piaractus brachypomus), monoculture of red claw crayfish (Cherax quadricarinatus) and polyculture tilapia (Oreochromis sp.) -cachama (Piaractus brachypomus). The economic models used for this particular analysis were Net Present Value (NPV) and Internal Rate of Return (IRR). Using these methods in combination with a sensitivity analysis foresaw the feasibility on investment for the monoculture of red claw crayfish (Cherax quadricarinatus) showing a Net Present Value (NPV) of 11,458.80 USD, which was the highest among the trials, at 8.65% real interest rate and Internal Rate of Return 44%, followed by the monoculture of cachama (Piaractus brachypomus) with NPV of 10,130.82 USD at the same discount rate and IRR 35%, respectively. The third place in order of profitability goes for the polyculture tilapia (Oreochromis sp.) and cachama (Piaractus brachypomus) with NPV of 1,888.99 USD and 8.65% real interest rate. The IRR percentage registered on the last type of culture was 19%, being the lowest among the three types of production analyzed. Among the conditions tested in the sensitivity analysis, there were: the sudden increase in discount rate, 10% increase in costs, 10% decrease in benefits, simultaneous 10% increase in cost and 10% decrease in benefits, 10% increase in feed cost, 10% increase in price of fingerlings and larvae and reduction in survival rate to 73%, 50, 25.1% with 80% as optimal. On this sensitivity analysis, the monoculture of red claw crayfish (Cherax quadricarinatus) overcame most of the conditions tested being defeated by the reduction in survival rate in the order of 50 and 25.1% which NPVs turned out to be negative; -7,429.60 USD and -22,004.70 USD, respectively. On this case the IRR was indefinable. Nevertheless, still some speculations about certain conditions such as broad experience in the Aquaculture field and technological advantage might be serious factors to be considered at the moment to select this investment and they must be analyzed carefully.