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In order to develop a system that could provide fish farmers with information to monitor stock performance and plan for a timely production, a computerised recording system was designed and tested on a trout hatchery in Scotland. It facilitated routine data capture on site with a small hand-held computer, programmed in BASIC language, which subsequently downloaded the data to a central desk-top microcomputer for further processing. Both direct and long-distance transmission via the telephone network using modems were possible. The LOTUS 1-2-3 general purpose software package, running on the microcomputer, was customised using 'macro' commands to accept the transmitted data and create files for storage on 'floppy' or 'hard' magnetic disks. Further information could be calculated and graphs and summary reports for stock control could be generated at will. Other customised LOTUS worksheets were developed to allow identification and access of specific historical data in order to calibrate regression equations and provide growth predictions for particular fish types. This information combined with cost and pricing details was further utilised by a linear programming package. Guidelines on optimum policies were formulated and sensitivity analyses could be performed. This production information system was implemented on the IBM-PC and the OLIVETTI M24 desk-top microcomputers and as field devices the SHARP PC 1500A and the HUSKY HUNTER were used. Since existing technology and 'off-the-shelf' software were utilised, the developed information system can be easily adjusted to suit the individual needs of different fish farms. However, the most important requirement for successful implementation would be the commitment and enthusiasm of the fish farm manager.

Made available in DSpace on 2016-12-08T16:24:17Z (GMT). No. of bitstreams: 1 PGCA14MA136.pdf: 1647918 bytes, checksum: ff7f5d61d4f253fad4a57167131394e1 (MD5) Previous issue date: 2014-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / World aquaculture has shown a steady growth with emphasis on fish farming . In the inland waters of altitude regions in Brazil, raising trout is an example of exponential growth of production. The rainbow trout Oncorhynchus mykiss is a exotic fish species, native to western North America and was introduced in Brazil to populate the rivers of naturally poor in native fish fauna highlands. The trout production is characterized as an intensive culture, achieving high productivity in small areas, representing an alternative economic activity. However, considering the high investment for the implementation and maintenance of cultivation, it is necessary to evaluate the economic viability of the activity. Therefore, the objective of this study was to analyze the economic viability of raising trout in small, medium and large-scale production based on the economic results obtained. In order to obtain economic data were taken as a basis three producers located in the cities of Bocaina do Sul, Painel and Urubici, being characterized as small and medium (perform fattening) and major producer (produces full-cycle), respectively. Based on the analysis of the economic viability of small and medium producers was observed that the two scales of production were economically viable, and larger scale production provided higher annual income (AI) and higher Net Present Value (NPV), but in general other indicators were very similar for the two producers. The results for the small to medium producer respectively were: Payback period on capital invested (PRC) 5.3 and 5.6 years; Cost Benefit Ratio (CBR) 1.54 and 1.63, Internal Rate of Return (IRR) of 18 and 19%. For large producer was possible to observe that the full production cycle is economically viable, showing excellent economic indicators. The large-scale production provided an annual income of R $ 1,123,467.00, the Payback period was fast (4.1 years on average), the Cost Benefit Ratio was 2.08 and the Internal Rate of Return was 24%. Based on the results it can be concluded that raising trout in small and medium scale is economically viable and that the small-scale production requires full time from producer. From the creation of different scenarios for the different scales of production was observed that the average scale is feasible to hire a technical manager, without compromising the economic results, which was not possible with the small producer. The full production cycle generates excellent economic results and increases the autonomy of the producer in relation to the supply chain, and do only fattening reduces profitability and increases the risks for the producer. Produce supplies such as ration improves economic outcomes and decreases the dependence on the market, but in return makes feed conversion worse. Working only with an industry was less profitable than full production cycle, and in that case the producer is dependent on the production of other properties to keep his unit operating. Finally, it was demonstrated that all scales of production are economically viable, but improper food handling can make the activity unviable, since the feed was the largest item of costing on all scales analyzed / A aquicultura mundial vem apresentando um crescimento constante com destaque para a piscicultura. Nas águas interioranas de regiões de altitude no Brasil, a truticultura é um exemplo de crescimento exponencial de produção. A truta arco-íris Oncorhynchus mykiss é uma espécie de peixe exótica, originária do oeste da América do Norte e foi introduzida no Brasil para povoar os rios das regiões serranas, naturalmente pobres em ictiofauna nativa. A produção de trutas caracteriza-se como sendo uma cultura intensiva, alcançando alta produtividade em pequenas áreas, representando uma atividade econômica alternativa. Entretanto, como é um alto investimento para a implantação e manutenção do cultivo, é necessário avaliar a viabilidade econômica da atividade. Assim sendo, o objetivo do presente estudo foi analisar a viabilidade econômica da truticultura em pequena, média e grande escala de produção com base nos resultados econômicos obtidos. Para a obtenção dos dados econômicos, foram tomados como base três produtores localizados nos município de Bocaina do Sul, Painel e Urubici, sendo caracterizados como pequeno e médio (realizam a engorda) e grande produtor (produz em ciclo completo), respectivamente. A partir da análise de viabilidade econômica do pequeno e médio produtor foi possível observar que as duas escalas de produção foram viáveis economicamente, e a maior escala de produção proporcionou maior renda anual (RA) e maior valor presente líquido (VPL), mas de maneira geral os outros indicadores foram bem semelhantes para os dois produtores. Os resultados para o pequeno e médio produtor respectivamente foram as seguintes: período de retorno do capital investido (PRC) 5,3 e 5,6 anos; relação benefício custo (RBC) 1,54 e 1,63 e uma taxa interna de retorno (TIR) 18 e 19%. Para o grande produtor foi possível observar que a produção em ciclo completo é viável economicamente, inclusive mostrando excelentes indicadores econômicos. Na grande escala de produção foi observado uma renda anual de R$ 1.123.467,00, um período de retorno de capital rápido (em média 4,1 anos), a relação benefício custo de 2,08 e a taxa interna de retorno de 24%. A partir dos resultados pode-se concluir que a truticultura em pequena e média escala é viável economicamente e que a produção em pequena escala exige dedicação integral do produtor. A partir da criação de diferentes cenários para as diferentes escalas de produção se observou que na média escala é viável a contratação de um responsável técnico, sem comprometer os resultados econômicos, o que não foi possível com o pequeno produtor. A produção em ciclo completo gera excelentes resultados econômicos e aumenta a autonomia do produtor em relação à cadeia produtiva, e fazer somente a engorda diminui a lucratividade e aumenta os riscos para o produtor. Produzir insumos como a ração melhora os resultados econômicos e diminui a dependência do mercado, mas em contrapartida piora a conversão alimentar. Trabalhar apenas com frigorífico foi menos rentável que produção em ciclo completo, e neste caso produtor fica dependente da produção de outras propriedades para manter sua unidade beneficiadora operando. Finalmente, foi demonstrado que todas as escalas de produção são viáveis economicamente, porém um manejo alimentar inadequado pode inviabilizar a atividade, já que a ração foi o maior item de custeio em todas as escalas analisadas

Thesis (MScAgric (Agricultural Economics))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The rising demand of fish due to population growth coupled by stagnation of fish supply from natural capture has led the world to turn to aquaculture to fill in the gap between fish supply and demand. Aquaculture has emerged as the only sustainable way of supplying the rising population with fish. However the rapid expansion of aquaculture has been met with growing concerns over its environmental effects especially waste produced from aquaculture. The net cage system that is currently being used by small scale trout farmers in the Western Cape is an open water based system where release of waste into the water bodies is inevitable and this put into question the long term sustainability of trout farming using net cages in irrigation dams in the Western Cape. This study sought to compare identified production techniques that can be used by aquaculture farmers to reduce accumulation of organic waste in irrigation dams. The proposed ‘clean’ production techniques include use of net cages fitted with Lift-up system, semi intensive floating tank system (SIFTS) and intergrated aquaculture systems. The study revealed that the intergrated aquaculture system is the most effective way of recovering waste that shows great potential of moving aquaculture towards long term sustainability as it fullfills sustainability dimensions such as ‘zero emission’, nutrient recycling and integrated production. Mechanical methods of recovering waste such as Lift-up system and SIFTS are also effective in recovering particulate waste but however dissolved nutrients are lost into the environment. The study went on further to investigate if economic, environmental and social benefits of recovering waste from irrigation dams outweigh the costs of recovering waste using different production techniques. Models of small scale aquaculture farms using the three identified production techniques were developed and compared with a modelled small scale net cage farm where there was no waste recovery. A comparative financial analysis of the modelled small scale trout farms using alternative production techniques carried out showed that trout production using any of the three alternative ‘clean’ production techniques is financially viable with the SIFTS production technique giving the farmer the highest returns, followed by the intergrated system, then the net cage with a Lift-up system and lastly the net cage system without waste recovery. The second part of the study used the contingent valuation method to estimate the environmental and social benefits of removing waste from dams. Households revealed that they were willing to pay (WTP) R40 on average annually to improve water quality from a state where eutrophication had occurred to a state suitable for irrigation and aquaculture. To improve water quality from a state suitable for irrigation to a state suitable for swimming, households were willing to pay R16.67 annually. If water was to be improved from a state suitable for irrigation to a level suitable for domestic purposes, average willingness to pay (WTP) was R26.17 annually. WTP indicate that besides financial benefits associated with using ‘clean’ production techniques there are environmental and social benefits that will arise to the farm community using water from the irrigation dams. / AFRIKAANSE OPSOMMING: Die stygende vraag na vis as gevolg van bevolkingsgroei, tesame met die stagnering van die aanbod van vis vanaf natuurlike vangste het daartoe aanleiding gegee dat die oë van die wêreld op akwakultuur gerig is om die gaping in die voorsiening van vis te vul. Akwakultuur het ontwikkel as die enigste volhoubare manier om aan die groeiende vraag na vis te voldoen. Die vinnige uitbreiding van akwakultuur het egter toenemende besorgdheid in die nadelige omgewingsimpak, veral ten opsigte van akwakultuurafval, tot gevolg gehad. Die nethokstelsel wat tans deur kleinskaalse forelboere in die Wes-Kaap in oop watergebaseerde sisteme gebruik word en die vrystelling van afval in die wateromgewings wat onafwendbaar is, plaas ’n vraagteken oor die langtermyn volhoubaarheid van die nethokstelsel forelboerdery in besproeiingsdamme in die Wes- Kaap. Die studie het ten doel gehad om geïdentifiseerde produksiestelsels wat deur akwakultuurboere gebruik kan word om die akkummulasie van organiese afval in besproeiingsdamme te verminder, te vergelyk. Die voorgestelde “skoon” produksietegnieke sluit in nethokke wat aan ’n opligstelsel gekoppel word, ‘n semi-intensiewe drywende tenk- stelsel (“SIFTS system” in Engels) en ‘n geïntegreerde akwakultuurstelsel. Met hierdie studie is bevind dat die geïntegreerde stelsel die mees effektiewe manier is om afval te herwin en toon potensiaal om akwakultuur op ’n vohoubare pad te plaas aangesien dit aan die volhoubaarheidsdimensies van geen emissie, voedingstofherwinning en geïntegreerde produksie voldoen. Meganiese metodes van afvalherwinning soos die nethokopligstelsel en die SIFTS-stelsel is effektief in die herwinning van vastestofdeeltjies, maar opgeloste voedingstowwe word steeds in die omgewing vrygestel. Die studie het voorts ten doel gehad om te bepaal of die ekonomiese, omgewings- en sosiale voordele om afval uit besproeiingsdamme te herwin, groter is as die herwinningskoste van die verskillende produksietegnieke. Modelle van kleinskaalse akwakultuurplase wat die drie geïdentifiseerde produksiestelsels gebruik, is ontwikkel en aangewend om te vergelyk met ’n nethokstelsel waar geen afvalherwinning gedoen word nie. ’n Vergelykende finansiële ontleding van die gemodelleerde kleinskaalse forelboerderye met die verskillende produksietegnieke is gedoen en daar is bevind dat enige een van die drie “skoon” stelsels finansieel lewensvatbaar is, met die SIFTS-stelsel wat die hoogste vergoeding aan die boer bied, gevolg deur die geïntegreerde stelsel, dan die nethokke aan ’n opligstelsel en dan die nethokstelsel sonder afvalherwinning. Die tweede deel van die studie het van die voorwaardelike (“contingent”) waardasiemetode gebruik gemaak om die omgewings- en sosiale voordele om afval uit besproeiingsdamme te verwyder, te bepaal. Huishoudings het aangetoon dat hulle bereid sou wees om tot R40 per jaar te betaal om die waterkwaliteit te verbeter vanaf ’n toestand waar eutrifikasie plaasgevind het na ’n toestand waar die water vir besproeiing en akwakultuur geskik sou wees. Om die waterkwaliteit vanaf ’n toestand geskik vir besproeiing te verander na ’n toestand geskik om in te swem, sou huishoudings bereid wees om R16.67 per jaar te betaal. Indien water vanaf ’n toestand geskik vir besproeiing verander sou word na ’n toestand geskik vir huishoudelike gebruik, sou huishoudings gewillig wees om jaarliks R26.17 te betaal. Die “gewilligheid om te betaal” dui aan dat daar bo en behalwe die finansiële voordele om van “skoon” produksietegnieke gebruik te maak, ook omgewings- en sosiale voordele vir die plaasgemeenskap bestaan met die gebruik van die water uit die besproeiingsdamme.

Thesis (MA (Geography and Environmental Studies))--University of Stellenbosch, 2006. / The Rural Aquaculture Development Programme (RADP) of the Division of Aquaculture at Stellenbosch University (DASU) has the objective of socio-economic development of farm workers and rural communities from previously disadvantaged communities through the provision of opportunities for sustainable economic development by establishing small-scale fish-farming systems on irrigation dams. The Small-Scale Aquaculture Farming Systems (SSAFS) is an initiative of RADP. DASU intends implementing 20 new projects by the end of 2005, 100 by 2010 and at least 200 by 2020. Thus far, sites which can accommodate 25 projects have been identified. The owners of the land on which these 25 possible projects are located are being contacted to gain permission to use the sites for the SSAFS. It is possible that some of the owners of the sites will not allow them to be used so that not all 25 projects will necessarily be implemented. At present the predominant search method employed by DASU to find new sites involves two steps. Initially knowledge is acquired through word of mouth about dams that may be suitable. Personnel then drive to these dams for further inspection, to see if they are indeed suitable. This method of search is clearly both expensive and time-consuming. Geographical information systems (GIS) have as yet not been considered as an alternative and/or supplementary site selection method for the SSAFS. GIS tools and principles can reduce both expenses and time in locating sites by reducing the number of dams to be visited to only those that are optimal (i.e. they present the least risk of the SSAFS projects failing). A new site selection methodology using GIS was developed which is faster and less expensive than existing site selection methods. The GIS site selection methodology revolves around the isolation and selection of dams in the Berg and Breede River water management areas, based on their ability to fulfil certain parameters of critical variables comprising dam dimensions, environmental issues, distance measures and site security, according to a priority hierarchy, that determine a successful site for trout farming according to methods employed by the SSAFS. Once this methodology was produced, it was presented to five people who are directly involved with the SSAFS as well as four others who are not involved with the SSAFS but who might find the methodology useful, to determine whether they hold that the methodology is indeed better than existing search methodologies. Those who were presented the GIS site selection methodology felt that it is very useful and that it could be employed in future to make more informed choices when locating new sites for the SSAFS as well as other aquacultural enterprises.

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