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Wong, Yuen-yee Queenie. "Mariculture practices in relation to water quality and the nearshore marine environment in Hong Kong /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22264188.
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Wu, Mei-yee. "Study on the feasibility of setting up a fish fry hatchery in Hong Kong." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43784501.
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Varvarigos, Panagiotis. "Microcomputer based fish farm production planning : the development of a microcomputerised data recording and production decision support system for individual fish farmers and its implementation on a fresh water trout hatchery." Thesis, University of Stirling, 1987. http://hdl.handle.net/1893/24822.
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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.
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Van, der Merwe Johan Philip. "Vergelyking van Tilapia (Oreochromis Mossambicus)en Koi (Ciprinus Carpio) in verskillende produksiestelsels." Thesis, Port Elizabeth Technikon, 2002. http://hdl.handle.net/10948/114.
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Die studie was uitgevoer om te bepaal of warmwaterspesies soos tilapia (Oreochromis mossambicus) en koi (Ciprinus carpio) gebruik kan word as deel van 'n roterende akwakultuur produksie sisteem in die Wes-Kaap. Drie produksiestelsels (drywende hokstelsel; gronddamme en hersirkuleringseenheid) was ge-evalueer vir beide tilapia en koi produksie. Twee verskillende diëte (tilapia, 32% proteien, 'n lae waarde dieet en koi, 32% proteien, 'n hoë waarde dieet) was ook ge-evalueer vir die effek op koi produksie. Tilapia- en koi vingerlinge was teen dieselfde lading (250/hok) in elke produksiestelsel geplaas. By die begin van die proewe het die tilapia vingerlinge 'n gemiddelde gewig van 60-80g en die koi vingerlinge 'n gemiddelde lengte van 30-40 mm gehad. Die visse is twee keer per dag gevoer en data is op 'n maandelikse basis oor 'n periode van 84 dae versamel. Produksie data vir die tilapia versamel was: 1) die gemiddelde daaglikse toename, 2) die totale voer verbruik, 3) water temperature en 4) mortaliteite is daagliks aangeteken. Die produksie data versamel vir koi wat twee verskillende diëte ontvang het in drie verskillende produksiestelsels was: 1) die gemiddelde daaglikse toename in lengte, 2) die totale voer verbruik, 3) water temperature en 4) mortaliteite is daagliks aangeteken. Die resultate van die tilapia studie het aangedui dat tilapia in die hersirkuleeringseenheid het deurgaans 'n swaarder gewig gehad (p<0.05) as die van die drywende hokstelsel en gronddam stelsel. Terwyl die gronddam stelsel weer 'n swaarder gewig gehad het as die drywende hokstelsel behalwe vir April (171,67 / 39,49 vs 159,33 / 22,15). Nieteenstaande die verskil in begin gewig en eind gewig in die guns van die tilapia in die hersirkuleringseenheid teenoor die ander twee stelsels het die GDT tussen die drywende hokstelsel en die hersirkuleringseenheid nie noemenswaardig verskil nie (1,20 / 0,15 vs 1,40 / 0,24). Die tilapia in die gronddamme het egter swakker (p<0,05) gewigstoename van 0,72 / 0,32 g gehad teenoor die tilapia in die drywende hokstesel 1,40 / 0,24 g en 1,20 / 0,15 g van die tilapia in die hersirkuleringseenheid. Tilapia in die gronddamme het dus ongeveer 45% swakker gemiddelde gewigstoename getoon as die van die drywende hokstelsel en hersirkuleringseenheid. Die produksiestelsel het 'n hoogs betekenisvolle invloed (p<0,001) op die groeipotensiaal van tilapia gehad in hierdie studie. Die gemiddelde totale hoeveelheid voer verbruik was nie statisties verskillend tussen die drywende hokstelsel en gronddam stelsel nie (29,83 / 2,66 vs 30,83 / 5,42), maar wel (p<0,05) vir die hersirkuleringseenheid (29,94 / 0,88). Die VOV het nie verskil tussen die drywende hokstelsel en hersirkuleringeenheid, maar daar was wel 'n verskil (p<0,05) tussen hierdie twee stelsels en die van die gronddamme. Die totale gemiddelde mortaliteite van tilapia was die hoogste (p<0,05) vir die drywende hokstelsel in vergelyking met die gronddamme en hersirkuleringseenheid. Die drywende hokstelsel het 14,67 / 14,61% meer mortaliteite gehad as die gronddamme en hersirkuleringeenheid. Die koi studie se resultate dui aan dat die tipe stelsel het 'n hoogs betekenisvolle (p<0,001) invloed gehad op die gemiddelde toename in lengte van die koi vis vir die somerseisoen. Die tipe dieet het geen invloed op die toename in lengte van koi vis vir al drie die stelsels ge-evalueer, maar die interaksie tussen dieet en die tipe stelsel was wel betekenisvol (p<0.05). Die interaksie tussen die tipe dieet en die tipe stelsel was die hoogste vir die groddamme 136,41 / 32,46 mm en 136,25 / 33,08 mm vir beide tilapia en die koi diëte gevoer. Die gemiddelde totale voer wat deur koi visse in die drie stelsels verbruik is, het wel statisties van mekaar verskil (p<0,05). Koi visse in die gronddam stelsel het meer voer verbruik vir beide die tilapia- en koi dieet (31,03 / 2,01 en 29,67 / 3,57) in vergelyking met die (26,35 / 2,44 ; 26,98 / 0,49 en 5,50 # 0,52 en 6,13 / 0,22) vir die drywende hokke en hersirkuleringseenheid stelsels onderskiedelik. Die % mortaliteite was betekenisvol (p<0,05) vir die verskillende stelsels. Koi visse in die hersirkuleringseenheid het die hoogste mortaliteite gehad vir beide die tilapia en die koi diëte (65,50 / 18,07% en 79,50 / 38,27%) terwyl koi visse in die gronddamme die laagste mortaliteite ondervind het (1,20 / 1,20% en 2,33 / 4,89%) vir beide die tilapia en koi diëte. Die koi in die gronddam stelsel het die beste resultate gelewer en dit is ook moontlik om koi 'n lae waarde dieet te voer sonder nadelige effekte op produksie.
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Lam, Kwok-hung Ken. "Sustainable development and property rights : a case study of pond fish culture in Hong Kong /." Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B20353170.
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Roberts, Laura Jayne. "Improving the survival and fitness of hatchery-reared salmonids in restoration programmes." Thesis, Swansea University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678416.
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Bolduc, Melanie B. "Long-term effects of habitat and management changes on steelhead production results from an individual-based model." Link to electronic thesis, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-050406-112805/.
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Wang, Yin-Han. "Model and software development for predicting fish growth in trout raceways." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4751.
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Thesis (M.S.)--West Virginia University, 2006.Title from document title page. Document formatted into pages; contains xii, 105 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 47).
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Triminio, de Meyer Suyapa. "Tilapia fingerling production in Honduras." Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Summer/master's/MEYER_SUYAPA_0.pdf.
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Chu, Yat-chun Jackson. "Education units of marine fish farming." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B2594650x.
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Bohner, Rodney. "Reproducing the River: Historic Context and Resource Survey of Oregon’s State Fish Hatchery System." Thesis, University of Oregon, 2018. http://hdl.handle.net/1794/23908.
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Oregon’s fish hatchery system developed in the late 1800’s in response to salmon fishery losses. Salmon hatcheries consist of a number of built components. ‘Growing fish’ requires a variety of building types which support the hatchery process as well as constant input of resources. In addition to surveying and inventorying fish hatchery resources, this study will analyze the social, economic, cultural, and environmental conditions under which these fish hatcheries were organized and commissioned. Ultimately, this survey will not only serve as a baseline for future, more intensive-level surveys, but will also provide a foundation for a National Register Multiple Property Submission. The use of hatcheries to sustain native Oregon fish species constitutes a major aspect of Oregon’s fishing and environmental conservation efforts. Oregon’s heritage hatcheries stand as physical reminders of early conservation activity and while their preservation provides a more complete picture of Oregon’s relationship with natural resources
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Lee, Gillian W. Y. (Gillian Wai Yien). "Development of winter flounder (Pleuronectes americanus) for aquaculture : effects of weaning, food type, density and temperature on growth and survival of wild and laboratory-reared juveniles." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22756.
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Winter flounder, Pleuronectes americanus, is being developed for aquaculture in Atlantic Canada. Since larval culture has been successful, research can now address problems at the juvenile stage such as weaning, diet and optimal growth environment. Weaning, a critical stage in culture of any flatfish species, is the switch from live food to an artificial diet. In a three month study, I was able to wean wild young-of-the year winter flounder from live, cultured Artemia onto dry food. Specific growth rates and food conversion indicated the artificial diet was a better food source than Artemia. In a second study, I was able to wean recently-metamorphosed winter flounder reared in the laboratory, onto two artificial diets which differed in price and lipid content. There was no difference between the inexpensive salmonid starter diet and the more costly Nippai diet on growth and survival. In a third study, I examined the effects of temperature and density on wild year 0 and 1 winter flounder reared on dry salmonid diet. There was no effect of density on growth and survival over the ranges tested. Greatest growth occurred at 15$ sp circ$C, although survival was highest at ambient temperature.
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Waring, Colin Peter. "Physiological effects of handling on turbot, flounders, and Atlanticsalmon." Thesis, Heriot-Watt University, 1990. http://hdl.handle.net/10399/890.
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Haylor, Graham S. "The culture of African Catfish, Clarias gariepinus (Burchell) in Africa, with particular reference to controlled hatchery production." Thesis, University of Stirling, 1992. http://hdl.handle.net/1893/3267.
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A rationale is presented for a primary nursing strategy and an on-growing strategy for Clarias gariepinus (Burchell) culture in Africa, thus providing a potential model for the development of culture technology for the species. Existing information pertaining to the production strategies identified is reviewed, highlighting the attributes of African catfish for aquaculture. Some of the current deficiencies and inconsistencies in available information pertaining to controlled hatchery production are addressed. The early developmental stages of Clarias gariepinus are defined, in order to promote consistent use of terminology and help farmers better address the changing needs of their developing stock. The pattern of growth and survival of larvae and fry is investigated at higher stocking densities than those used experimentally to provide a database for planning full-scale commercial operations. Tank design and water flow rates appropriate for Clarias gariepinus in hatcheries are investigated and recommendations made. Finally, in order to promote maximal growth rates of hatchery stocks the maximum daily feed intake of larvae in relation to different feeding regimes is estimated based on rates of gastric evacuation and return of appetite. An overview of the controlled hatchery production of Clarias gariepinus is presented.
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Rosell, R. S. "Incubation of crustacean eggs in vitro." Thesis, University of Liverpool, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377136.
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Fizer, Eric G. "Characteristics of turbulence and design of solid removal system in the quiescent zone of an aquaculture raceway." Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10453.
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Thesis (M.S.)--West Virginia University, 2009.Title from document title page. Document formatted into pages; contains xx, 195 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 125-126).
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Gestring, Kelly Brad. "The effects of handling and transportation on Coho salmon fry incubated in hatchboxes." Thesis, Thesis (M.S.)--University of Oregon, 1989, 1989. http://hdl.handle.net/1794/9808.
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Soares, Silvia. "Fish farm health evaluation : interpretation of site mortality records." Thesis, University of Stirling, 2012. http://hdl.handle.net/1893/9268.
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In aquaculture worldwide, diseases are a significant constraint to economic expansion. The Scottish salmonid industry has experienced many cycles of development, with episodes of little or negative profitability caused by excess of production, and times of crisis due to different disease problems. In Scotland, the early implementation of regulation largely contributed to the control of infectious disease outbreaks. The recent Chilean outbreak of infectious salmon anaemia (ISA) illustrated the threats and the impacts of disease in the aquaculture industry and the importance of implementing good regulation and husbandry practices to reduce the impact of the spread of infectious disease. Databases of site production data have an important role to play in the investigation and understanding of diseases. They store valuable data collected during the time of production, which are essential for the identification of potential health and production problems during the production cycle of farmed fish. Mortality records are one of the most important sources of information on a farm, especially if it includes the cause of death as deformities, predators and diseases. Any deviation from the expected levels of mortality may indicate production problems, infectious diseases, or inadequate welfare. The investigation of increased rates of mortality must include examining farm records, determining the influence of death rate on production and the potential risk factors of diseases in a farm. This project demonstrated the importance of mortality records for setting industry standards of “expected” mortality losses and for investigating the value of recorded mortalities as a tool for aiding in surveillance and control of infectious diseases. It also aimed to determine the utility of reported mortality in supporting and assisting management-strategy decisions at the farm and industry level. In this project, we developed a baseline benchmark curve for expected mortality losses for Atlantic salmon in seawater. This novel approach constitutes a first attempt to establish a baseline curve for normal mortality, which allows detection of potential production problems based on deviations of mortality from the baseline curve of normal mortality. The results of this study also indicated that mortality levels may vary across production cycles, which can again be identified by using the baseline. We found that site was the factor with the highest contribution to variance in mortality. This site-to-site variation in mortality may have resulted from epidemics and environmental incidents, or other local event/effects. Temperature, and/or geographical area were also characteristics that contribute to variation in mortality. The regulator, Marine Scotland Science, with the backing and support of the salmonid industry has suggested potential mortality thresholds as an indicator of presence of infectious diseases, which could be used as alerts for inspection by the official authority. In this study, high mortality rates on fish farms were investigated as an indicator of the presence of infectious disease. The analysis was performed using several analytical approaches: receiver operating characteristic (ROC) curve analysis, measures of sensitivity and specificity, and bootstrap methods. The study was performed by splitting the production cycle into small fish with mean weight below 750 g and large fish with mean weight over 750 g. In the small fish, the results did not suggest reported mortality as a strong indicator of the presence of infectious disease, which may be caused by the lack of records of infectious disease at this stage of the production cycle. In the larger fish, high mortality rates were found to be a strong potential indicator of the presence of infectious diseases, including the suggested mortality threshold. In a survey, the role of traditional diagnosis in the prevention and control of disease outbreaks was assessed. For that, key informant interviews were performed with open questions to the health or farm manager of several trout and Atlantic salmon farms and we also used the diagnostic reports of the Veterinary Diagnostic Services (VDS) from Stirling University to triangulate the data. We showed that disease diagnoses are of great importance for disease identification and control of actual diseases. Farmer’s experience was also indicated as essential in the identification of the first signs of disease, which was principally through the daily monitoring of fish. This study suggested that disease diagnosis starts at the farm level with the daily monitoring of fish and the records of different parameters by the farmer, including mortality. Those records were showed to be vital to identify problems within the production. This thesis illustrated a novel approach to investigate and interpret recorded mortality at the farm level. The results presented in this thesis indicated reported mortality as a vital on-farm tool for identification of diseases and production problems. This thesis suggested priority areas where further investigation is required.
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John, K. Riji. "Characterization of reovirus-like agents associated with snakehead fish and cell culture." Thesis, University of Stirling, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244645.
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Langan, Laura. "Fish intestinal cultures for ecotoxicological studies : in vitro and primary culture models." Thesis, University of Plymouth, 2017. http://hdl.handle.net/10026.1/9486.
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Ecotoxicity testing of chemicals for environmental risk assessment is an area where a high number of vertebrates are used across a variety of industrial sectors. The application of the 3Rs in toxicity testing using fish address both the ethical and societal concerns around this issue in addition to the increasing legislative requests for the incorporation of animal alternatives. This thesis aims to highlight the potential of 3D cell culture models to "bridge the gap" between in vitro and in vivo screening procedures for testing of chemicals with the potential to persist or bioaccumulate thereby improving the predictive power of screening procedures. This thesis examines two alternative methods for their potential use as an intestinal based toxicokinetic tool for environmental risk assessment, utilising an in vitro fish cell line replacement tool (RTgutGC). In addition, for the first time a new intestinal primary cell culture based model was developed to address both intestine region specific response (pyloric, anterior, mid and posterior) and size related adaptability to toxins. Paramagnetic oximetry was used to measure oxygen content within 3D structures (spheroids) in order to better understand the microenvironment of these culture models. Using histology, immunohistochemistry, transepithelial electrical resistance (TEER), transmission electron microscopy (TEM), metabolic, fluorescence and gene expression assays, the comparability of this system to native intestinal response was established. Following exposure to carefully chosen environmental contaminants (Benzo[a]pyrene and Copper), the RTgutGC cell line demonstrated comparable responses to existing literature in terms of uptake, metabolism, DNA damage and the presence an equivalent saturable level. Primary enterocytes cultured on transwell inserts remained viable for upto six weeks, with permeability and metabolic activity comparable to native tissue (both in vitro and ex vivo). Taken in combination, these features of enterocytes represent a profile more closely representative of the intestine then the widely used "gut sac" method. With the potential advantages of incorporating complexity at differing levels (connective tissue layer, intestinal bacteria biome), the intestinal models described offer the potential to screen highly persistent toxins which may require prolonged incubation, in addition to the exploration of complex experimental designs which minimise animal usage (uptake, depuration, uptake). As a consequence, the models developed within this thesis significantly enrich the emerging fish based in vitro testing strategies.
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ZARANTONIELLO, MATTEO. "Future feeds in aquaculture: insects as a new ingredient for fish culture." Doctoral thesis, Università Politecnica delle Marche, 2022. http://hdl.handle.net/11566/299201.
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Nell’ambito di un’acquacultura in continua espansione, la formulazione dei mangimi è stata identificata come uno dei principali fattori che possono comprometterne la sostenibilità ecologica ed economica. In questo contesto, la presente tesi di dottorato è stata incentrata sulla valutazione di una possibile transizione verso formulazioni mangimistiche innovative, caratterizzate da contenuti ridotti di materie prime convenzionali e non più sostenibili e dall’utilizzo della farina di prepupe di Hermetia illucens (mosca soldato nera) come ingrediente alternativo. Questa specie di insetto (i) è caratterizzata da un buon profilo nutrizionale e dalla presenza di molecole bioattive che possono esercitare un ruolo benefico sulla salute dei pesci e (ii) rappresenta una promettente soluzione per la possibilità sfruttare la sua grande efficienza di conversione del substrato di crescita per migliorare ulteriormente il suo profilo nutrizionale (specialmente in acidi grassi polinsaturi omega 3 a lunga catena) permettendo di introdurre il concetto di economia circolare nel settore dell’acquacoltura. Nella presente tesi, sono stati studiati gli effetti fisiologici di diversi livelli di inclusione di farina di prepupe di Hermetia illucens nella dieta, inizialmente su un modello sperimentale (zebrafish; Danio rerio) considerando il suo intero ciclo vitale e il possibile impatto sulla generazione successiva e, successivamente, su specie di interesse commerciale, una d’acqua dolce (storione siberiano, Acipenser baerii) e una marina (orata, Sparus aurata), dando particolare risalto alle performance di crescita, alla composizione in acidi grassi del filetto e alla salute del fegato e del tratto intestinale. Nel complesso, i risultati ottenuti hanno evidenziato che percentuali di inclusione di farina di prepupe rispetto a ingredienti di origine marina e vegetale fino al 50 e al 40 %, rispettivamente, possono promuovere la salute e il benessere dei pesci allevati e la qualità del prodotto. In particolare, le prove sperimentali incluse nella presente tesi rappresentano un esempio di come l’acquacoltura possa essere implementata con il riutilizzo di sottoprodotti derivati da altri settori e con la sostituzione parziale degli ingredienti convenzionali con alternative più sostenibili garantendo, al contempo, la produzione di pesci sani e la riduzione dell’impatto ambientale.In an ever-expanding aquaculture industry, aquafeed formulation has been identified as one of the key factors challenging the long-term ecological and economical sustainability of this sector. In this context, the present PhD thesis aimed to evaluate the possible transition to future feeds in aquaculture characterized by lower amounts of conventional marine- and plant- derived raw materials by using the Black Soldier Fly (Hermetia illucens; BSF) prepupae meal in aquafeed formulation. This insect species (i) is characterized by a good nutritional profile and by the presence of bioactive molecules that can exert a beneficial role on fish health and (ii) represents a promising solution due to the possibility to take advantage of its high feed conversion efficiency to ameliorate its nutritional profile (especially in terms of n3 long-chain polyunsaturated fatty acids) giving the possibility to introduce the circular economy concept to aquaculture sector. In the present thesis, the physiological effects of different dietary inclusion levels of BSF prepupae meal were investigated firstly on an experimental model (zebrafish; Danio rerio) considering its whole life cycle and the possible impact on the first filial generation and then focusing on a freshwater (Siberian sturgeon, Acipenser baerii) and a marine (gilthead seabream, Sparus aurata) farmed fish species, giving particular emphasis to fish growth, fillet fatty acids composition and liver/gut health. Overall, results obtained evidenced that dietary inclusion levels of BSF prepupae meal respect to marine- and plant -derived ingredients up to 50 and 40 %, respectively, can promote fish health, welfare and quality of the product. Specifically, the fish trials performed for the present PhD thesis represent an example of how aquaculture could be implemented with the re-use of land-produced by-products and with the partial substitution of conventional ingredients with more sustainable and eco-friendly ones like BSF prepupae meal, while sustaining the production of healthy fish and reducing the associated environmental footprint.
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Goosen, Neill Jurgens. "Investigation of potential bio-active properties and effects on production performance of aquafeed ingredients derived from fish processing waste by way of enzymatic autolysis." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95907.
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Thesis (PhD) -- tellenbosch University, 2014.ENGLISH ABSTRACT: This study is part of the continuing global research effort dedicated to finding alternative aquafeed ingredients, which not only replace fish meal and fish oil as sources of essential nutrients in aquafeeds, but also provide specialist functional properties when included in feeds. Due to constraints in supply of fish meal and fish oil originating from wild capture fisheries, the continually growing aquafeed industry requires new sources of raw materials for the production of high quality feeds. The aim of the study was to investigate the specialist functional properties of feed ingredients (with emphasis on immune-stimulation potential) derived from fish processing waste after enzymatic hydrolysis by endogenous proteolytic enzymes (autolysis). Further aims were to (i) quantify effects of these feed ingredients on production performance of two species relevant to the South African aquaculture industry, namely Mozambique tilapia Oreochromis mossambicus and South African abalone Haliotis midae, (ii) compare performance to commercially available enzymatically produced feed ingredients, and (iii) separate the functional effects of these fish processing waste derived feed ingredients from the acid used to preserve them against bacterial spoilage during the autolysis process. Oil recovered after autolysis of rainbow trout viscera proved to be an attractive feed ingredient due to favourable effects on the non-specific cellular immune function of both Mozambique tilapia and South African abalone. However, in South African abalone, increased immune function due to inclusion of fish oil was accompanied by a significant decrease in production performance. The inclusion of hydrolysed proteins, obtained by autolysis of fish waste, in aquaculture feeds also improved non-specific immunity and survival of Mozambique tilapia significantly – independently of the preserving acid – although the same was not observed for South African abalone. Production performance was dependent on dietary hydrolysed protein inclusion levels in both species; excessive inclusion resulted in decreased production performance. The performance of dietary hydrolysed protein from autolysis and those from commercial production processes were significantly different, possibly as a result of different raw material origins and production processes. It is further shown that formic acid can contribute to improved water stability in abalone feeds, a novel mode of action not previously described. The study concludes that the simple autolysis process for processing of fish waste can provide aquafeed ingredients with immune stimulatory potential, which can contribute to improved production performance in the Mozambique tilapia and the South African abalone. The result can contribute to improved sustainability of the aquafeed industry, through substitution of fish meal and fish oil derived from capture fisheries with processed fish waste components.
AFRIKAANSE OPSOMMING: Hierdie studie vorm deel van die voortdurende en wêreldwye soeke na nuwe akwakultuur voerbestanddele wat nie net vismeel en –olie kan vervang as bron van noodsaaklike voedingstowwe nie, maar wat ook gespesialiseerde funksionele eienskappe openbaar wanneer dit in akwavoere ingesluit word. As gevolg van beperkings in die voorsiening van vismeel en –olie afkomstig vanaf wilde visserye, word die voortdurend groeiende akwavoer bedryf genoodsaak om nuwe grondstowwe te benut vir die vervaardiging van hoë kwaliteit voere. Die doelwit van die studie was om moontlike gespesialiseerde funksionele eienskappe (met spesifieke klem op potensiële immuun-stimulasie) van voerbestanddele te ondersoek wat herwin is vanaf reënboogforel proseseringsafval, na ensiematiese hidrolise d.m.v. endogene ensieme teenwoordig in die afval (outolise). Verdere doelwitte was om (i) effekte op produksie prestasie van hierdie bestanddele te kwantifiseer in twee akwakultuur spesies relevant tot die Suid- Afrikaanse bedryf (naamlik die Mosambiekse kurper Oreochromis mossambicus en die Suid- Afrikaanse perlemoen Haliotis midae), (ii) om produksie prestasie te vergelyk met kommersieel beskikbare voerbestanddele voorberei d.m.v. ensiemtegnologie, en (iii) om die moontlike effekte van die voerbestanddele te skei van die van die sure gebruik om die bestanddele te preserveer tydens die outolitiese proses. Daar is bevind dat olie herwin na outolise van reënboogforel ingewande ‘n goeie voerbestanddeel is wat gunstige effekte op die nie-spesifieke, sellulêre immuniteit van beide Mosambiekse kurper en Suid-Afrikaanse perlemoen gehad het. In die Suid-Afrikaanse perlemoen het verbeterde immuunfunksie gepaard gegaan met ‘n verswakking in produksie prestasie. Die gehidroliseerde proteïen komponent van ge-outoliseerde prosesseringsafval het ook beduidende verbetering in nie spesifieke immuniteit en oorlewing van Mosambiekse kurper tot gevolg gehad - onafhanklik van die preserverende suur - maar dieselfde is nie in die Suid-Afrikaanse perlemoen waargeneem nie. Produksie prestasie was afhanklik van die insluitingsvlakke van gehidroliseerde proteïen in beide spesies en dit is bevind dat oormatige insluiting produksie nadelig beïnvloed. Prestasie van proteïen afkomstig van outolise en die van ‘n kommersiële produksieproses het beduidend verskil, moontlik as gevolg van verskillende grondstowwe en prosesseringstegnieke. Daar is verder vir die eerste keer getoon dat mieresuur ‘n beduidende verbetering in waterstabiliteit in sekere perlemoenvoere teweeg kan bring. Die studie kom tot die slotsom dat die eenvoudige outolise proses funksionele akwavoerbestanddele kan produseer wat kan bydra tot ‘n verbetering in produksie prestasie in die Mosambiekse kurper en Suid-Afrikaanse perlemoen. Die resultaat kan bydra tot verbeterde volhoubaarheid van die akwavoer bedryf, deur vismeel en –olie afkomstig van wilde visserye, te vervang.
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Fu, Chi-wing, and 傅志榮. "An evaluation of the accredited fish farm scheme in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46734429.
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Brumbaugh, Erica Nicole. "Using fish culture ponds to examine factors affecting larval hybrid striped bass growth and survival." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1268241546.
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Waning, Kate M. "Two Bioeconomic Studies on Haddock Culture: Live Feed and Juvenile Production." Fogler Library, University of Maine, 2002. http://www.library.umaine.edu/theses/pdf/WaningKM2002.pdf.
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Min, Hojune. "Effects of nutrients from fish farms on culture of blue mussel (Mytilus edulis)." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for biologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-14589.
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Intensive salmonid cage culture releases nutrients and organic matter that lead eutrophication of coastal waters. Integrated multi-trophic aquaculture (IMTA) is receiving great attention as a means of reducing organic/inorganic nutrient loads to the environment and increasing productivity by rearing viable secondary organisms. In this study blue mussels (Mytilus edulis) were cultured close to a salmon (Salmo salar) cage farm at Tristen, Bjugn in Sør Trøndelag, Central Norway from June 2010 to February 2011. 3 experimental stations at the fish farming area and 2 reference stations (1.8 and 3.6 km away from the fish farm, respectively) were positioned to test if the integrated mussel culture reduces the environmental impact from salmon cage culture.Highest water temperature recorded was 14.3 °C in July. Water temperature was above 10 °C until middle of October and the lowest was 3.1 °C in winter. Total particulate matter (TPM) and chlorophyll a contents varied 6.3 – 10.5 mg L-1 and 0.1 - 2.5 µg L-1, respectively. The mussel (n=450) length increased from 31.1±0.04 mm (standard length±SE) to 41.5±0.17 mm. The mussel growth was high in summer (June – September) and was close to zero in the winter (October – February). Multiple regression analysis showed that water temperature was the prime factor affecting condition index (CI) (meat dry weight/shell dry weight) and specific growth rate (SGR) of mussel. No differences were found in the environmental variables and food availabilities among the stations. Significantly higher CIs at the experimental stations (station 1, 2 and 3) than at the reference stations were caused by utilization of fish farm discharges by the mussels. Fatty acids 18:1 (n-9), 18:2 (n-6) and 20:5 (n-3) signatures and the ratio of n-3 to n-6 in the digestive gland tissue of mussels collected in February support the findings. SGR in shell length was highest at reference station 5 (0.29 % day-1 in summer and 0.02 % day-1 in winter). This result might be caused by slow current speed at the station.It is concluded that, mussels may play an important role reducing environmental impact from salmon farm and it gives a possibility to integrating mussels on the salmon cage culture.
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Hu, Zhewei. "Aqua + Culture: Intergrating Fish, Farming, and Flood-control Systems on Four Mile Run." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/72227.
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This thesis begins with the study of a highly integrated agricultural system called dike-pond system in Pearl River Delta, South China. From the study, two aspects of dike-pond system are found interesting. One is the material flow in the system which makes full use of the by-products. The other is the function of preventing flooding by protecting crops on the dike and increasing water storage capacity with ponds. Duplicating the system to other parts of world seems impossible because of the weather conditions, technical requirements to operate the system and its intensive labor requirement. However, in a broader view, it seems possible to apply the concepts of reusing "waste" and preventing flood to other places.
With the inspiration of this system, this thesis studies how the concept might be adapted to Washington Metropolitan area. Several specific questions are critical to the inquiry: How to integrate different components into a system according to local situation? How to produce multiple products that feedback into the flow of materials and resources just like dike-pond system? How to reuse 'waste' or forgotten resources? How to prevent floods without using an engineered flood wall? How to create a place that people can have different fishing experiences in urban region? How to provide a habitat for urban wildlife?
My thesis addressed these questions through a design for a public space along the downstream of Four Mile Run in Arlington, Virginia. With design criteria derived from case studies and literature review, this project aims to control floods, cycle organic matter in wetlands, ponds and farm fields, provide fishing places, fish habitat, open spaces... All in an integrated system with little waste and a wise reuse of the "waste" water.Master of Landscape Architecture
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Gomathy, S. "Studies on the hydrology and the abundance of phytoplankton of fish culture ponds." Thesis, Central Marine Fisheries Research Institute, 1990. http://eprints.cmfri.org.in/11063/1/Gomathy%20S..pdf.
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The sun is the major source of energy for all the
activities of life on earth. Photosynthesis is the prime
mechanism by which the autotrophs use the solar energy
and the carbon dioxide and water from the environment to
synthesize food for themselves and the heterotrophs.
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Salehi, Hassan. "A strategic analysis of carp culture development in Iran." Thesis, University of Stirling, 1999. http://hdl.handle.net/1893/2643.
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The thesis is concerned with the strategic analysis of carp culture development in Iran, based on an assessment of the supply potential from various forms of carp farming, and on the potential demand, market features and price determinants for carp and carp products. Based on a sample of 188 farms from the three main carp farming provinces plus two case studies, all farmers in all locations and categories made a profit, with feed and fertiliser dominating variable costs. Considerable variation in production costs and profitability was observed. Where some degree of investment and support services have been provided, major increases in output have occurred. The culture of carp is technically possible in a variety of conditions within the country, though, expanding large scale farming mainly depends on reducing the cost of feed and fertiliser. Future targets could be to integrate with other agricultural activities, intensify smaller farms in the Caspian area, and consider developing larger scale commercial production in Khuzestan. A market and consumer survey was conducted, including a sample of 357 consumers in Tehran and Karaj, and 96 sellers in 11 main cities from 6 provinces. Younger consumers had the strongest preferences for ready meals product, while to increase consumption, a rise in income and decline in price will have a greater effect on older groups, larger sized families and educated people. The growing willingness to buy new product forms, particularly by younger consumers, educated groups, inland urban dwellers and high-middle income groups might be expected to increase demand. A range of supply/demand scenarios has been presented, offering projections for the year 2010, suggested target levels of 284,000-348,000t. In broad terms a policy for carp production was described to meet these targets. As in developing markets elsewhere, the traditional wholesale sector may lose its position as multiple retailers and supermarket chains become increasingly important outlets for carp and its products, and opportunities may arise for adding value in a range of ways. Within rural areas, and smaller cities, consumers may also increase their ability to buy fresh fish at the farm gate or at local outlets.
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Shamshak, Gina Louise. "Economics of bluefin tuna aquaculture in the United States /." View online ; access limited to URI, 2009. http://0-digitalcommons.uri.edu.helin.uri.edu/dissertations/AAI3368006.
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Puttinaowarat, Suppalak. "Detection and characterisation of aquatic Mycobacterium spp." Thesis, University of Stirling, 1999. http://hdl.handle.net/1893/21429.
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Mvcohacterium spp, the etiological agent of mycobacteriosis, has recently been responsible for serious infections in two economically important fish species cultured in Thailand; snakehead (Channa striata) and Siamese fighting fish (Berta splendens). Attempts to detect and identify the pathogens to species level, in fish tissue and the environment, have so far been unsuccessful, mainly due to the poor levels of sensitivity and specificity of the detection methods used, based on conventional bacteriology and histology. In this study, a variety of novel techniques were developed and used for more effective identification of Mycobacterium spp., including monoclonal antibody-based assays, DNA-based techniques and mass spectrometry. A monoclonal antibody (Mab 8F7) probe was developed against M. marinum, which was successfully used to identify M. marinum in infected fish tissue by immunohistochemistry (IHC), and from pure bacterial cultures by enzyme-liked immunosorbent assay (ELISA). The molecular-based techniques employed to detect the pathogen included in situ hybridisation (ISH), polymerase chain reaction (PCR) and reverse cross blot hybridisation. The PCR was developed using primers available from the literature which amplified mycobacterial 16S rDNA. The products of the reaction were identified to species level by PCR-reverse cross blot hybridisation. M. inarinum, M. fortuitum and M. chelonae were identified using this method. The same primers as those used in the PCR, were used as probes in ISH to identify Mycobacterium spp to genus level in infected fish tissues. spectrometry. A range of Mvcohocterium spp. isolated from fish located in different geographical regions were identified and characterised using Mab 8F7, pyrolysis mass spectrometry (PyMS) and PCR-reverse cross blot hybridisation and PyMS analysis showed that three distinct groups of mycobacteria were involved in mycobacteriosis in Thailand and Israel. The groups were clustered around either type strains M. fortuitum-M. chelonae or M. marinum, or around an unspeciated Mycobacterium spp. The unspeciated isolates were identified as M. marinum by PCR analysis and were mainly isolated from fish cultured in Israel. M. marinum from Israel and Thailand appeared to be different from each other since the isolates from Thailand reacted positively with Mab 8F7, whereas isolates obtained from fish in Israel were negative. PCR-reverse cross blot hybridisation was used to establish the identity of Mycobacterium spp involved in mycobacteriosis outbreaks affecting Siamese fighting fish and snakehead fish in Thailand. PCR was also utilised to analyse environmental samples taken from these farm sites. Siamese fighting fish farmers are known to suffer from skin lesions caused by Mycobacterium spp and therefore biopsies were taken from the farmers for analysis by PCR-reverse cross blot hybridisation. Analysis revealed that two species, M. fortuitum and M. marinum, were involved in the mycobacterial infections observed in both fish species. M. fortuitum and M. marinum were also both found in environmental samples including water, sediment and fish food. However, M. fortuitum was the isolate most frequently found. Skin lesions were only observed amongst the Siamese fighting fish farmers, while the snakehead fish farmers did not seem to be effected. Analysis of the biopsies from the skin lesions by PCR reverse cross blot hybridisation revealed that M. fortuitum was the main etiological agent associated with these lesions.
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Kruger, David Philip. "Aspects of nutrition of the swordtail fish, Xiphophorus Helleri, (Family : Poeciliidae) under intensive culture conditions." Thesis, Rhodes University, 1996. http://hdl.handle.net/10962/d1005062.
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The aim of this work was to investigate the nutrition of a popular ornamental fish, the swordtail (Xiphophorus helleri), under intensive aquaculture conditions. The study focused on the formulation and manufacture of artificial dry diets, as well as the influence of livefeed supplementation on growth and nutritional indices of both juvenile and broodstock fish. A combination of 65% fishmeal and 35% soya oil cake meal was found to closely approximate the essential amino acid profile of X helleri (r² = 94,3%) and lysine was identified as the first limiting amino acid. The influence of dietary protein and energy on the growth of X helleri was investigated by means of a growth trial comparing a range of nine test diets combining 3 crude protein (45,38 and 30%) and 3 digestible energy (16,5, 14,5 and 12,5 kJ/gram) levels. A high crude protein content (45% dry matter) and a protein to energy ratio of ≥ 27 mg protein per kJ digestible energy was shown to promote optimal growth rate and feed conversion ratio in juvenile X helleri. The final body protein and lipid content of the fish were significantly correlated with the dietary protein to energy ratio. The nutritional value of identical dietary formulations prepared by drum-drying or cold extrusion techniques and presented either as flake or crumble particles was evaluated in a growth trial and through analysis of vitamin C levels in the diets. Up to 27% of vitamin C activity was destroyed during the drum-drying of flake diets, while 80% of the remaining vitamin C was lost through leaching within 10 minutes of immersion in water. A crumble-type diet was shown to be acceptable to X helleri, and yielded significantly better growth rate and feed conversion than the equivalent flake feed. Almost 19% of fish fed the flake diets developed vitamin C deficiency symptoms including scoliosis and lordosis, while this was completely prevented by feeding crumbles, indicating a significant restriction of leaching losses from this type of particle. The use of livefeed (Daphnia spp.) as a daily supplement to dry feeds was shown to result in a significant improvement in growth rate and survival of juvenile swordtail fish. Furthermore, the synergistic action of nutrients contained in the livefeed resulted in an improvement in the feed conversion efficiency of the artificial formulation. While mortalities of 13,4% and 15% were recorded in fish fed exclusively on flake feed or Daphnia, no mortality occurred in the group fed the supplemented diet. Furthermore, the incidence of vitamin C deficiency symptoms was prevented by daily supplementation with Daphnia. Fish fed exclusively on Daphnia exhibited significantly more intense pigmentation due to carotenoids contained in the livefeed. In broodstock fish maintained primarily on flake diets, growth rate, feed conversion ratio as well as reproductive performance, as measured by fecundity, were significantly improved by daily livefeed supplementation. Weekly supplementation showed no measurable advantage over flake feed only. A direct correlation was demonstrated between fecundity and size of female fish with a mean fecundity of 190 embryos per female in those fed a daily Daphnia supplement. This was significantly higher than the yield from the non-supplemented or weekly supplemented treatments (133 and 140 embryos per female respectively). Despite these differences, the number of young harvested during the experiment did not differ between treatments and this discrepancy was ascribed to parental cannibalism of newborn juveniles. This phenomenon constitutes a major potential bottleneck in production with estimates of up to seventy percent of young lost in some exp experimental tanks. In conclusion, the present study demonstrated that established aquaculture nutrition principles and techniques are applicable to the tropical ornamental fish species, X helleri. It was demonstrated that by using balanced crumble feed formulations, and regular livefeed supplementation, production yields under intensive conditions may be significantly improved. Suggestions for future work on poeciliid production in South Africa include investigation of the economic implications of the recommendations stemming from this project, and further research into effective restriction of parental cannibalism of newborn fish.
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Padhi, Abinash. "Electrophoretic Profile of the general proteins in the Green (Perna viridis Linnaeus) and the Brown (Perna indica Kuriakose & Nair) mussels." Thesis, Central Marine Fisheries Research Institute, 1998. http://eprints.cmfri.org.in/11022/1/Abinash%20Padhi.pdf.
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The electrophoretic profiles of the general proteins and the selected enzymes
(MDH and EST) were examined in the green mussel, P. viridis and the brown
mussel P. indica and their suspected hybrids from South India. The protein and
the enzyme profiles were distinctly different in the two species. The protein
profiles in different tissues of the green and brown mussels were found tissue and
species specific. The two species are genetically different. The protein and the
enzyme profiles in the brown and suspected ‘brown type’ hybrids were similar and
that of the green and the suspected ‘green type’ hybrids were also similar. The
suspected hybrids may be the colour morphs of the respective species.
Morphometric studies on these two species and the suspected hybrids also
corroborated the above findings.
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Vine, Niall Gordon. "Towards the development of a protocol for the selection of probiotics in marine fish larviculture." Connect to this title online, 2004. http://eprints.ru.ac.za/196/.
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Wu, Mei-yee, and 胡美儀. "Study on the feasibility of setting up a fish fry hatchery in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43784501.
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Skonberg, Denise. "A nutritional approach to reduce phosphorus pollution in hatchery effluent /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/5304.
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Leung, Ka-ming, and 梁家銘. "Isolation, identification and establishment of bacterial culture collection of fish pathogens in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/207649.
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The importance of fish culture has been increasing since 1990’s. The steady growth of fish culture helps to ensure a stable supply of fish for human consumption. However, when compared with capture fisheries, production from fish culture is greatly influenced by fish diseases. Outbreaks of fish diseases have caused great economic loss to fish culture. Research has been conducted to understand and reduce the occurrence of fish diseases in fish culture. In Hong Kong, bacterial infection is the most common cause of fish diseases. This project is therefore directed to isolate and identify the causative bacterial pathogen of some fish disease cases with the aim of setting up a local fish disease database for assisting the identification of diseases and improving the understanding of fish diseases in fish farms in Hong Kong. In this project, seven fish disease cases caused by bacteria were investigated with the AFCD officials in Hong Kong. Nine fish disease bacterial pathogens were isolated and identified using different methods (including commercial biochemical test kits, automated system and DNA sequencing). The bacteria identified included Aeromonas hydrophila, Lactococcus garvieae, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus iniae, Vibrio vulnificus and Aeromonas salmonicida. Sensitivity tests to 10 common antibiotics conducted for the identified bacteria showed that spectinomycin is the most broad spectrum antibiotics. In addition, a long-term physical storage of bacterial stock with glycerol and glass beads was established for further research of the identified bacteria. For efficient data analysis, an electronic database using Microsoft Access to hold the identification results and case history of each isolated bacteria was developed. Different data entry forms and reports were also constructed to facilitate easy data entry and data access for users. The three bacteria identification methods were compared for their efficiency and accuracy. Some limitations encountered in this project including time constraints and low accuracy of some biochemical identification tests were discussed and recommendations to overcome these limitations and improvements to the constructed database were made.published_or_final_version
Environmental Management
Master
Master of Science in Environmental Management
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Chen, Yrong-Song. "Waste outputs and dispersion around marine fish cages and the implications for modelling." Thesis, University of Stirling, 2000. http://hdl.handle.net/1893/26683.
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Aquaculture plays an increasingly important role in food production as the catches of wild fish stocks continue to decline on a global scale through overfishing. However, the rapid development of intensive cage aquaculture in particular, which requires high inputs of energy, food and capital, can result in adverse effects on the environment. While spatial distribution and sediment loading models for particulate wastes from marine fish cages have been under development for more than 10 years, the models still contain numerous assumptions that limit their usefulness. These include the use of very limited data for fish feed and faecal pellets sinking rates that take no account of food manufacturer, type or size or environmental conditions. The present study provides information on a range of pellet types for three of the most important European farmed fish species (i.e. Atlantic salmon Salmo salar L., sea bream Sparus aurata, sea bass Dicentrachus labrax) that may be readily incorporated into models. Such data, combined with validation of predictions through in situ field investigations is designed to help improve the accuracy and usefulness of solid waste dispersal models. The studies comprise four main sections, i.e., quantifying food and faecal pellet characteristics, examining nutrient leaching rates from uneaten food and fish faeces, determining resuspension characteristics of uneaten food, modelling of solid wastes dispersion and thus the development of environmental tools. Existing literature relating to environmental impacts of cage aquaculture is reviewed and the key factors highlighted. Two preliminary studies provided information on the influence of gravity acceleration on settling velocity determination and appropriate techniques for monitoring the rate of nutrient leaching from faecal wastes. Settling velocities of Atlantic salmon diets were significantly greater at 20 psu salinity than at 33 psu and significantly higher for most pellet types at 10°C than, at 20°C. Settling velocities for unsoaked salmon diets were found to increase with pellet size, from a mean of 5.6 cm s-1 for the smallest pellet (2 mm) to 13.9cm s-1 for the 10 mm standard (20 to 24% fat) pellets. Settling velocities of extruded diets for sea bream and sea bass diets ranged from 3.9 to 10.6 cm s-1, broadly similar to those for salmonid diets. Settling velocities of salmon pellets were not significantly affected by immersion time (0 - 15 min). Given the water depths at fish cage sites and the settling times involved, it is concluded that it is unnecessary to take account of changes in food pellet settling velocity as a result of immersion. Freshly net-collected salmon faecal pellets appeared to consist of fine solid material approximately the size of the formulated diets. The range of salmon faecal settling velocities was 3.7 to 6.2 cm s-1 (mean = 5.3 cm s-1) at 15°C and 33 psu. There are no significant differences in nutrient leaching of carbon and nitrogen from all six salmon diets after 20 min immersion in sea water. However, a rapid loss of faecal nutrients occurred 2.5 to 10 min after immersion in sea water. Total C and total N were found to leach by as much as 22% and 26%, respectively, after 5 min immersion during one sampling occasion. Experiments conducted in a large-scale flume tank showed the critical resuspension velocities of a range of commercial fish feeds were between 8.63 cm s-1 and 9.53 cm s-1. Above the critical resuspension speed, pellets moved by saltation, i.e. traveling along the sediment by rolling, sliding or hopping on the bed. The velocities of pellet resettlement ranged between 0.79 cm s-1 and 3.98 cm s-1 under the critical resuspension speeds. Field trials, involving the deployment of sedimentation traps, showed a general relationship between sedimentation of material and distance from cages, i.e. more sedimented material was associated with sampling sites closest to the cages. The spatial changes in sedimentation rates in the first trial were between 15.4 and 31.7 g DW m-2 d-1 at 30 m and 10 m stations, respectively. Values in the second trial (38.5-65.5 g DW m-2 d-1) were twice those in the first trial, but followed the same pattern. The model presented in this thesis is a combination of a spreadsheet model (Microsoft Excel 6.0) and Surfer plot program (Golden Software Ltd., ver. 6.04). Excel is used to prepare basic mathematical operations behind the model, including a mass balance submodel and use of a formula for calculating dispersion of uneaten food and faeces on the sea bed developed by Gowen et al. (1989). The operation of the waste dispersion model for marine cages takes into account the various settling characteristics of waste particles. It was verified with a set of in situ sedimentation data obtained from the field trial described above. Results described the waste dispersal around the vicinity of the cage farm. For the future, it is intended that further validation and optimisation of the model will be carried forward by a combination of both increasing user involvement and incorporation of data from comprehensive studies as these become available. Together, these will contribute to reducing and remedying the environmental impacts of future development.
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Ekman, Elisabet. "Natural and experimental infections with Flavobacterium psychrophilum in salmonid fish /." Uppsala : Dept. of Pathology, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/v160.pdf.
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Lückhoff, Paul Daniël. "Application of the condition factor in the production of African sharptooth catfish Clarias gariepinus /." Link to the online version, 2005. http://hdl.handle.net/10019/1098.
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Britz, P. J. (Peter Jacobus) 1959. "Environmental requirements for the hatchery rearing of African catfish Clarias Gariepinus (Pisces: Clariidae) larvae and juveniles." Thesis, Rhodes University, 1988. http://hdl.handle.net/10962/d1001964.
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Inadequate seed production has historically been a factor limiting the commercial culture of Clarias gariepinus. The need to determine the environmental requirements of larvae was identified, in order to facilitate their successful mass rearing in hatcheries. The effects of key environmental factors on the growth, survival and aspects of the behaviour of C. gariepinus larvae and juveniles were investigated under controlled conditions. A strong emphasis was placed on the interpretation of the observed responses in terms of the natural history of the animal. Larvae were obtained by artificially inducing and spawning feral adult broodfish. Larval growth rates were highest in the temperature range 26-33ºC, with a peak at 30ºC. Survival of larvae was high between 22 and 33ºC. The final temperature preferendum of juveniles, determined in a thermal gradient was 30ºC, and it was concluded that this temperature is probably optimal for most of the physiological processes of the animal. Larvae and juveniles displayed strong negative phototaxis. When reared under different photoperiod regimes, larval growth increased with longer dark periods, however a similar rate of mortality was recorded in all photoperiod treatments. The provision of cover was found to enhance larval growth under conditions of continual light (24L/OD), however under conditions of continual darkness (OL/24D) similar growth rates were recorded regardless of the presence or absence of cover. All growth rates in continual darkness (OL/24D) were higher than those in continual light (24L/OD), regardless of whether cover was provided or not. It was concluded that a OL/24D photoperiod is optimal for larval rearing. At salinities between 0 and 5% similar growth and mortality rates of larvae were recorded. At 7.5 % larval growth and survival rates were lower, and at 10 % all larvae died within 48 hours. The 96h-LCSO for unionised ammonia was found to be 2.3 mg/l. The cytological effects of unionised ammonia were evident as degenerative changes in the gill and liver tissues. In an investigation of tank hygiene, it was found that larval growth and survival rates were highest in tanks not cleaned at all. As the frequency of tank cleaning increased, the growth and survival rates of larvae decreased. When reared at densities ranging from 45-450/1, larval growth was found to be density dependent. A model of hatchery productivity (number larvae of standard size produced/time/vol.) was developed based on the density dependent nature of larval growth. The model predicts that maximum productivity, will be achieved at a rearing density of 1400/1. The high growth and survival rates obtained over a broad range of each environmental parameter investigated serve to explain how larvae survive and grow in their unstable floodplain habitat in nature. The broad environmental tolerances of C. gariepinus are of benefit with respect to the culture of larvae, as successful larval rearing is possible over a fairly wide range of environmental conditions.
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Littler, Tabetha Marie. "Frequency of Aeromonas spp. detection in rainbow trout and recirculation aquaculture systems and the storage stability of fillets." Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5348.
Full textAbstract:
Thesis (M.S.)--West Virginia University, 2007.Title from document title page. Document formatted into pages; contains vi, 93 p. : ill. Vita. Includes abstract. Includes bibliographical references.
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Koesoemadinata, Santosa. "Aquatic toxicology of selected rice insecticides, with special reference to their effects on fish culture in West Java, Indonesia." Thesis, University of Stirling, 1990. http://hdl.handle.net/1893/3530.
Full textAbstract:
Insecticides are widely used in SE Asian countries to control insect pests in rice, mainly stemborers (Chilo suppresallis) and brown plant hoppers (Nilaparvata lugens). The use of highly toxic insecticide compounds, however, is known to cause serious problem for fish culture in wet rice fields in many of these countries, particularly in Indonesia where this practice assumes a tremendous "house hold economic" importance, as well as being an essential part of the nation's inland aqua-culture production system. The laboratory and field experiments described were carried out to establish whether the application of five selected rice insecticides (fenobucarb, isoprocarb, buprofezin, diazinon and alphamethrin) would influence the growth and production of common carp fingerlings (Cyprinus carpio LINN.) raised in wet rice fields. Laboratory static toxicity tests revealed that the carbamate insecticides (fenobucarb and isoprocarb) were the least toxic insecticide compounds. The 96 hour Median Lethal Concentration (i.e the concentration that killed 50% of the test fish in 96 hours exposure period, under specified conditions) of these insecticides were 5.8mgl-1 and 5.3mgl-1, respectively. The synthetic pyrethroid insecticide alphamethrin was the most toxic insecticide with 96h-LC50 of 0.037mg1-1, while the organophosphate diazinon and the thiadiazin buprofezin showed intermediate toxicity to common carp (96h-LC50 = 2.3mgl-1 and 1.5mgl-1, respectively). A series of five field experiments were consecutively conducted, using 24 specially constructed rice field plots to accomodate the culture of common carp fingerlings for a period of 21 days. A single application of three dose regime, i.e 1/2X, 1 X and 2X of the recommended dose rate for insect control was given as treatment in each experiment. The survival of fish in all experiments were not significantly influenced by the insecticide treatment (P > 0.05). The growth rate and the production of fish biomass in rice fields treated with isoprocarb, buprofezin, diazinon and alphamethrin, were also found to be comparable with those in the untreated control plot (P > 0.05). In the rice fields treated with the highest dose rate of fenobucarb (1500gha-1 ,Al), the growth and production of fish were significantly lower than those in the untreated control rice fields (P < 0.05). Observations on the rice field biota revealed no definite pattern in the temporal changes of the population of zooplankton and macroinvertebrates both in the insecticide treated plots as well as in the untreated control plots. The minimum effects of the insecticide treatment to fish and rice field biota observed in the experiment were presumably due to several factors, mainly because a significant amount of the compounds were adsorbs by the rice field soil and aquatic vegetations and not onto the water, causing less toxicity, followed by the rapid flushing of the chemicals from the rice field system. The composition of the diet of common carp fingerlings in the rice field was found to be similar with those reported in the natural ponds, consisting mainly of aquatic insects (and their larvae), crustaceans, benthic macroinvertebrates and plant detritus. Based on the results of the present experiments, of the five insecticide compounds tested, diazinon and fenobucarb appeared to produce greater risk to fish when used in rice-fish farming. The use of agrochemicals in rice-fish farming should be carefully managed and controlled, using selected low toxic and non-persistent insecticides based on the result of laboratory and field toxicity tests.
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Choi, Wai Ming. "Culturing grass carp and grey mullet using food waste incorporated with traditional Chinese medicine, Baker's yeast and enzymes." HKBU Institutional Repository, 2013. https://repository.hkbu.edu.hk/etd_oa/12.
Full textAbstract:
The present study focused on using food wastes and feed supplements, e.g. enzymes (bromelain and papain), baker’s yeast and Traditional Chinese Medicines (TCMs) for rearing freshwater fish (grass carp and grey mullet) in Hong Kong. Different types of food wastes, e.g. meats, bones, cereals, fruits and vegetables were collected from local hotels, mixed in different ratios and processed into feed pellets for feeding trials. The cereal dominant food waste feed (FW A) was more suitable for grass carp and grey mullet, with the best growth performance (e.g. feed conversion ratio (FCR), specific growth rate (SGR)) and higher protein digestibility (in grass carp), compared to FW B and FW C which contained higher proportions of meat products. The NBT (Nitroblue Tetrazolium) activities in blood and plasma protein levels were decreased in the grass carp, cultured with food waste feeds without any supplements, compared to the commercial feed, Jinfeng®, 613 formulation (Control). Upgrading FW A by the addition of 1% and 2% mixtures of bromelain and papain significantly increased the feed protein solubility and subsequent to growth (SGR and relative weight gain (RWG)) and feed utilization (e.g. apparent net protein utilization (ANPU), protein efficiency ratio (PER)) in both fish species. The protein and feed utilizations by grass carp were also promoted by the yeast supplements with the optimal dose of 2.5% yeast (S. cerevisiae) added to FW A upgraded by enzymes. This showed that yeast could further enhance nutrient utilization contained in feeds after addition of bromelain and papain. The in vitro study on the grass carp’s plasma treated with TCM extracts also showed that TCM extracts could stimulate plasma bactericidal activity (on Aeromonas hydrophila), possibly through enhancing plasma complement activity. The formulation with Radix scutellaria, Rhizoma coptidis, Herba andrographis and Radix sophorae flavescentis in the ratio of 1:1:2:3 was more effective in enhancing plasma bactericidal activity than single TCM extracts. Besides, R. coptidis and R. scutellaria possessed the strongest antimicrobial activity (in vitro) on fish pathogens (such as A. hydrophila, Lactococcus garvieae and Vibrio cholerae) among the 17 tested TCMs. In addition, TCMs were less likely for developing drug resistant pathogens than antibiotics. Grass carp immunity (NBT activity in blood, plasma bactericidal activity and total immunoglobulin level) was boosted by the addition of TCM formulation and baker’s yeast (S. cerevisiae). The disease resistance to pathogen (A. hydrophila) was also enhanced, with significantly lower mortalities observed in groups feeding with TCM (1 and 2% for 21 to 28 days) and baker’s yeast (2.5 and 5% for 28-56 days). The uses of yeast and TCMs led to positive effects on growth, immunity and disease resistance to pathogens in fish, but the effects (grass carp) were less effectual when both were supplemented in feed. The combined use of both supplements may impair the effects of TCM formulation or yeast in the modulation of gut mircoflora, and upset the balance of beneficial microbial communities. The present study demonstrated the feasibility of using feed supplements (TCM and baker’s yeast) to enhance fish immunity and enzymes upgraded food waste feeds for rearing fish, for the development of a more sustainable aquaculture in Hong Kong.
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Schmitz, Mark Harvey. "Comparative Growth of All-Female Versus Mixed Sex Yellow Perch (Perca flavescens) in Recirculating Aquaculture Systems." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/42798.
Full textAbstract:
Nine, production-scale, recirculating aquaculture systems were utilized to
compare the growth parameters between all-female and mixed sex yellow perch stocks.
Each system was stocked with 455 fish m-3 and contained one of three different biofilter
types: a rotating biological contactor, a trickling filter or a bead filter. The all-female
fingerlings (S1) used were originally derived from Lake Mendota, Wisconsin. The
mixed-sex fingerlings (S2) used were originally derived from Lake Erie. Temperature
and photoperiod (23oC, 16H-L) were maintained at levels for optimal growth.
Absolute growth rates ranged from 0.27-0.48 g/day. Mean final density within
treatments was 42.8 kg/m3 and ranged from 37.2-50.2 kg/m3. The main effect of stock
did not have a significant effect on growth (p > .1). All-female treatments exhibited more
uniform growth. The main effect of filter type did have a significant effect on fish
growth (p < .01), with fish in tanks containing trickling filters exhibiting significantly
higher growth. Total feed conversion averaged 1.61 across all treatments and ranged
from 1.38-1.78. S1 treatments consumed a significantly higher percent body weight per
day than S2 treatments (p < .05).
Analysis of PIT tagged individuals revealed that the mean relative growth rate
was significantly higher in S2 individuals (513.9%) compared to S1 individuals (315.3%:
p < .01). S2 females (597.8%) grew 1.9 times faster than S1 females (315.3%: p < .01).
Within S2 individuals, females (597.8%) grew 1.5 times faster than males (395.2%: p <
.05). For all individuals, 33.6% of the variation in final weight was explained by the
variation in initial weight. Differences in the geographic strain or culture history of these
stocks may have had a larger overall effect on growth than sexual classification (all-
female or mixed sex).
Dress percentage of skin-on butterfly fillets was examined in 20 individuals per
stock and in six groups of 20 individuals per stock. Within S2 individuals, 73.7% were
female. Mean fillet yield was significantly greater in S1 individuals (47.6%) compared to
S2 individuals (43.0%: p < .01). Mean GSI in S1 individuals (1.01%) was significantly
higher than S2 individuals (0.54%: p < .05). Within S2 individuals, mean GSI was
significantly higher in females (0.70%) when compared to males (0.08%: p < .05). Fillet
yield was significantly greater in S1 groups (47.2%) compared to S2 groups (44.9%: p <
.01). Within each stock fillet yield increased with size.
The difference in fillet yield demonstrated between these stocks may be a result of
differences in strain of origin. The identification of superior yellow perch strains or
strain crosses with regard to growth rate and fillet percentage is of considerable
importance to the industry.Master of Science
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Pienaar, Anthony Graham. "A study of coeval sibling cannibalism in larval and juvenile fishes and its control under culture conditions." Thesis, Rhodes University, 1990. http://hdl.handle.net/10962/d1005469.
Full textAbstract:
The primary objective of this study was to examine environmental parameters thought to affect cannibalism in certain fish species. It was found that environmental, behavioural, genetic and physiological factors all affect cannibalism in the species exhibiting the phenomenon. The diversity of factors nfluencing cannibalism served to illustrate the complexity of this behaviour pattern. Feeding to satiation was found to suppress cannibalism in catfish, trout and koi carp. High population densities were found to increase the rate of cannibalism, thereby acting as a population regulation mechanism for catfish, trout and the common and koi carps. Live food, as compared with dry pelletized feed was found to significantly suppress cannibalistic aggression. Catfish grown in total darkness, provided with refuges and living in turbid conditions were found to exhibit lowered cannibalistic and territorial aggression. Various lines of evidence suggested that cannibalism has a genetic basis, as was shown by the differences in cannibalistic behaviour of the two strains of Cyprinus carpio, viz. common and koi carp, with cannibalism being higher in the latter. This finding substantiates the hypothesis that cannibalism is genetically controlled and therefore open to evolutionary change. It is concluded that cannibalism is adaptive in times of food limitation, but that it is merely a by-product of normal feeding behaviour when food is abundant. Since cannibalism is advantageous and thus adaptive, the question arises ai to whether selection is occurring at the individual or the population level (or both). It was concluded that it is acting at the individual level, and that any benefits accruing at the population level iv were simply the effect of the initial cause, viz. individual selection. One of the aims of this study was to determine whether cannibalistic tendencies in fish are influenced by differing life history style trajectories. Based on the results of this study it is hypothesized that cannibalism is an r-selected trait. wi th the understanding gained from the knowl edge of the fundamental principles governing cannibalism, certain recommendations for its control in fish culture could be made. It is, however, imperative that further intensive studies be carried out to understand more fully this complex subject. General "rules" for regulating cannibalism could be helpful for any given cannibalistic species. However, in considering the differing life-history styles of each species, it becomes evident that species-specific guidelines need to be worked out. Until then, any suggestions for cannibalistic control offered to the aquaculturist can only serve as unrefined tools.
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Jones, Clifford Louis Wilshire. "Intercohort cannibalism and parturition-associated behaviour of captive-bred swordtail, Xiphophorus helleri (Pisces: Poeciliidae)." Thesis, Rhodes University, 2003. http://hdl.handle.net/10962/d1007812.
Full textAbstract:
Adult fish that belong to the family Poeciliidae cannibalise juveniles, both in the wild and under captive conditions, but this behaviour has only been partly investigated in the Poeciliidae in some of the commercially valuable species. The objective of the research is to develop an understanding of intercohort cannibalism and parturition-associated behaviour in captive-bred swordtail (Xiphophorus helleri), with applications to industry and future research of other poeciliids. Experiments investigating the effect of adult stocking density and sex ratio on the production of juveniles were used to determine if cannibalism occurs under culture conditions. The average rate of intercohort cannibalism ranged from (5.5 to 53.9%), and was positively density dependent and independent of sex ratio, indicating that males and females were probably equally cannibalistic. The highest number of juveniles (1725.7±141.4) produced per tank over 70 days was obtained from two males and eight females. To develop a better understanding of adult and juvenile behaviour during parturition, fish were observed under controlled laboratory conditions using video and behaviours such as attack (burst of speed by an adult in the direction of a juvenile), escape (avoidance of cannibalism after attack) and cannibalism (predation of a live juvenile by an adult), for example, were identified. Under laboratory conditions most young escaped in downward direction after attack (49%) and most utilised the refuge made that was made available. Furthermore, most attacks (62-65%) and cannibalism (57-84%) occurred at the bottom. Since the presence of refuge significantly increased the rate of juvenile survival under culture conditions, it was hypothesised that the rate of cannibalism could be reduced under farming conditions if juveniles were protected when they escaped downwards. This hypothesis was accepted as it was found that refuge at the bottom of the water column or the inclusion of a false-bottom reduced the rate of cannibalism by 49% and 72%, respectively. Similarly, the hypothesise that the rate of cannibalism could be reduced if juveniles where given protection when escaping sideways (32% of juveniles escaped sideways in the laboratory) was also accepted when tested under farm-scale conditions because a false-side reduced the rate of cannibalism by an average of 45%. Since males and females were equally responsible for cannibalising juveniles in the laboratory, it was hypothesised that the rate of cannibalism would decrease proportionately with the removal of males (Le. 20% of the cannibals) from the population; the removal of males under farming conditions resulted in a 19.5% reduction in the rate of cannibalism. Since older juveniles were better able to escape cannibalism than neonates and since adults habituate to stimuli that previously resulted in attack behaviour, it was hypothesised that the rate of cannibalism would remain unaffected by the length of time that juveniles were exposed to adults in the breeding tanks. This hypothesis was also accepted when tested under farm conditions. However, some hypotheses based on laboratory observations were not accepted. For example, a constant low light intensity did not appear to decrease the rate of cannibalism under farm conditions; also, the occurrence of dead and deformed juveniles went unnoticed in the laboratory, and under farm conditions, where adults did not have access to the bottom of the tank, 10% of the harvest consisted of dead and deformed juveniles. It is concluded that technologies, such as bottom-refuge or a false-side, that increase the size of the liveharvest and allow for the removal of potentially less viable offspring are recommended for the commercial production of poeciliids. The overall similarity of X. helleri behaviour between the laboratory experiments and the farm-scale trials suggests that the post-partum behaviour of X. helleri remains consistent under these different conditions; thus, behaviour under one set of conditions may be used to predict behaviour under other conditions. The application and significance of extrapolations to industry and future research of X. helleri and possibly other poeciliids were discussed and the most applicable laboratory observations with the highest extrapolation capacity were proposed. Furthermore, techniques were developed to aid industry and future researchers in making predictions relating to behaviour of X. helleri under different conditions based on laboratory observations. The results were used to develop a model indicating that selection pressures against cannibalism are not likely to exist at the rate of cannibalism observed here since the potential genetic gain through kin survival and inclusive fitness was shown to be greater than any potential genetiC loss experienced by a victim of cannibalism. The model was successfully tested under a range of social conditions. Other possible explanations for cannibalism in poeciliids, such as parental manipulation, nutritional advantages, opportunistic predation and the recovery of energy are discussed. It is suggested that the most likely proximate cause of cannibalism under captive conditions is opportunistic predation. The theory that cannibalism ensures that only viable genes of the victim are expressed, through inclusive fitness, is a possible ultimate cause of cannibalism, which may have been inherited from feral ancestors of captive-bred X. helleri.
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Mackay, Stephen John. "An investigation of growth, feeding and body composition of Australian bass, Macquaria Novemaculeata in freshwater growth ponds : by Stephen Mackay." Thesis, Queensland University of Technology, 1994. https://eprints.qut.edu.au/37069/1/37069_Mackay_1994.pdf.
Full textAbstract:
Australian bass (Macquaria novemaculeata Steindachner) fingerlings are currently available from fish hatcheries but little work has been carried out on the grow-out of this species. The aim of this investigation was to provide information on the diet and growth of the species in two managed growth ponds; a nursery pond and a grow-out pond.
The growth of Australian bass was found to be superior to that of wild bass populations, although survival rate was very low. After 54 weeks, mean total length was 132mm (range 108-151 mm) and mean weight was 28.94g (range 16.31-41.869). Length-weight relationships for bass were determined for each study pond:
log10W = -5.262 + 3.226Iog10TL (nursery pond)
log10W = -4.768 + 2.930log10TL (grow-out pond)
where W is weight (g) and TL is total length (mm). Relative condition was determined by the formulae Australian bass (Macquaria novemaculeata Steindachner) fingerlings are currently available from fish hatcheries but little work has been carried out on the grow-out of this species. The aim of this investigation was to provide information on the diet and growth of the species in two managed growth ponds; a nursery pond and a grow-out pond.
The growth of Australian bass was found to be superior to that of wild bass populations, although survival rate was very low. After 54 weeks, mean total length was 132mm (range 108-151 mm) and mean weight was 28.94g (range 16.31-41.869). Length-weight relationships for bass were determined for each study pond:
log10W = -5.262 + 3.226Iog10TL (nursery pond)
log10W = -4.768 + 2.930log10TL (grow-out pond)
where W is weight (g) and TL is total length (mm). Relative condition was determined by the formulae nursery pond with age. Relative condition was not significantly related to surface water temperature or pH, but was close to significant for Secchi depth.
The proximate composition of Australian bass varied significantly with age. Moisture content decreased from 78% to 68% between 6 and 15 weeks of age, but remained at approximately 70% up to 54 weeks. Crude protein content remained relatively constant. Crude lipid varied seasonally, reaching a peak of 27.5% in mid-summer (24 weeks of age). Mineral content increased by 3% over the study period. The relationships between total length and mineral content and total length and moisture content of Australian bass were well described by linear regression equations. Equations could not adequately describe the relationship between total length and protein and lipid content of Australian bass. Similar relationships were found between fish age and the same proximate components. The amino acid composition of 12 and 54 week old Australian bass remained relatively constant. Although significant differences occurred in the glycine, hydroxyproline, praline, taurine and tyrosine content these are not essential amino acids. The amino acid profile of Australian bass was similar to other freshwater fishes.
In culture ponds bass ingested most available food types. The diet initially consisted of zooplankton and aquatic insects and later included gudgeons. Notable exceptions from the diet were aquatic coleoptera, amphibians and errestrial insects. Bass up to 125mm TL (total length), or approximately 41 weeks of age, ingested zooplankton. Dipteran larvae, (especially chironomid larvae), ephemeropteran nymphs and trichopteran larvae were other numerically important prey types. Despite the availability of gudgeons
(Hypseleotris spp.) they did not appear in the diet until 28 weeks of age.
Australian bass displayed diurnal feeding behaviour at 12 and 28 weeks of age, but not at 50 weeks. Significantly higher numbers of zooplankters were ingested during daylight hours. In contrast, feeding on aquatic insects was not restricted to any specific time, but varied with each prey taxon.
Despite the generalised nature of the diet, bass were selective feeders, selecting cyclopoid copepods, Moina sp., ephemeroptera and culicidae. Corixids and notonectids were not selected prey items. The criteria for selection of food items would appear to be prey mobility and evasiveness.
On the basis of the results obtained in this study it is suggested that the extensive culture potential of the Australian bass warrants further investigation, especially in the areas of water quality tolerances of the species (specifically turbidity tolerances) and the maximum growth rates possible on natural foods.
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Pynn, Ralph M. "The Newfoundland and Labrador cod trap fishery : the basis for a future cod grow out industry /." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ42432.pdf.
Full text
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Lam, Kwok-hung Ken, and 林國雄. "Sustainable development and property rights: a case study of pond fish culture in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31238750.
Full text