Dissertations / Theses on the topic 'Aquaculture'
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Erzini, Gabriel de Castro. "Automatic control of an aquaculture system." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/16545.
Full textThis thesis covers the automated aquaculture scenario around the world and speci cally Portugal. With research done, a case study and laboratory work, the goal is to create a reliable remote control system capable of not only controlling the physical variables within an aquaculture system but monitor and rectify unwanted situations.
Esta tese trata-se de aquacultura pelo mundo e Portugal especi camente. Com uma pesquisa feita, um "case study" e trabalho laboratorial, o objetivo é criar um sistema de controlo remoto capaz de controlar as variáveis físicas dentro de um sistema de aquacultura e monitorizar e reti car situações indesejadas.
Switz, Theodore R. "Sustainability of applied aquaculture in the US." Online pdf file accessible through the World Wide Web, 2007. http://archives.evergreen.edu/masterstheses/Accession86-10MES/Switz_T%20MESThesis%202007.pdf.
Full textStewart, J. Alan. "Assessing sustainability of aquaculture development." Thesis, University of Stirling, 1995. http://hdl.handle.net/1893/2164.
Full textDieta, Romeo Esquivel. "Aquaculture development in the Philippines." Thesis, University of Hull, 1997. http://hydra.hull.ac.uk/resources/hull:4708.
Full textGyllander, David. "Ethical Aspects of Norwegian Aquaculture." Thesis, Linköpings universitet, Institutionen för kultur och kommunikation, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-124237.
Full textYoshida, Grazyella Massako. "Mate selection in aquaculture species." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/153170.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Os objetivos deste trabalho foram: (i) testar a eficiência do algoritmo de seleção de acasalamento (MS) em controlar o nível de endogamia e coascendência, além de aumentar os ganhos genéticos; (ii) incluir a variabilidade genética da futura progênie como componente de otimização na função objetiva de seleção de acasalamento usando dados de dois programas de melhoramento aquícolas; e (iii) comparar a MS com a seleção truncada (TS) e contribuição genética ótima (OCS), combinados com diferentes estratégias de acasalamentos para controlar a endogamia e manter os mesmo níveis de ganhos genéticos. Para os objetivos (i) e (ii), o total de 8.782 tilápias do Nilo (NT) de cinco gerações e 79.144 salmões coho (CS) de oito gerações foram utilizados para otimizar as funções objetivos e vinte gerações discretas foram simuladas para o objetivo (iii), considerando 50 famílias e 2.000 filhos por geração, e uma característica com herdabilidade igual a 0.30. As OFs foram otimizadas considerando a coascendência média dos pais, o mérito genético esperado, a endogamia da futura progênie para os objetivos (i) e (iii) e a variabilidade genética da futura progênie foi adicionada na OF para o objetivo (ii). Para o objetivo (i), a MS permitiu reduzir a endogamia em até 73% para tilápia do Nilo, em comparação com a seleção truncada e até 20% para o salmão coho, em comparação com o cenário real de acasalamento. No objetivo dois, a MS permitiu produzir progênie com maior (DP = 0.77 e 0.30 para NT e CS, respectivamente) ou menor (DP = 0.25 e 0.14 para NT e CS, respectivamente) dispersão dos valores genéticos, dependendo da função objetivo otimizada. A seleção de acasalamentos superou a seleção truncada e o cenário real de acasalamento e também foi possível alterar a variabilidade genética da futura progênie, quando esse componente foi considerado na OF utilizado os dados reais. Para os dados simulados, a MS teve melhor performance comparada com a TS e a OCS combinada com acasalamentos aleatórios. A curto-prazo, a MS foi mais eficiente do que a OCS combinada com os acasalamentos que minimizam a endogamia em controlar a endogamia sob o mesmo nível de ganho genético. Porém, a longo prazo os resultados entre as duas estratégias foram muito semelhantes. De forma geral, o algoritmo de seleção de acasalamentos foi eficiente e flexível em otimizar a função objetiva usando diferentes componentes, em diferentes aplicações práticas na aquicultura.
The aims of this work were: (i) test the efficiency of mate selection (MS) algorithm in controlling the inbreeding and coancestry level, as well, increase the genetic gain; (ii) include the genetic variability of the future progeny as component for the optimization of the MS objective function in two aquaculture real dataset; and (iii) compare MS among truncation selection (TS) and optimum contribution selection (OCS) scenarios combined to different mating strategies to assess the best method in controlling inbreeding and maintain the genetic gain, for aquaculture breeding using simulated dataset. For objective (i) and (ii), a total of 8,782 Nile tilapias (NT) from five generations and 79,144 coho salmon (CS) from eight generations were used to optimize the objective functions (OF) and twenty discrete generations were simulated for the objective (iii), considering 50 families and 2,000 offspring per generation, and a trait with heritability of 0.30. The OFs were optimized accounting to coancestry of parents, expected genetic merit and inbreeding of the future progeny for the objective (i) and (iii) and in addition the genetic variability of the future progeny was considered for the objective (ii). For the objective (i), the mate selection allowed reducing inbreeding up to 73% for NT, compared with truncation selection, and up to 20% for CS, compared with realized scenario. In the objective (ii), MS allowed producing animals with higher (SD = 0.77 and 0.30 for NT and CS, respectively) or lower (SD = 0.25 and 0.14 for NT and CS, respectively) dispersion of estimated breeding value, depending on the objective function optimized. For real data set the MS outperformed the real mates and truncation selection and in addition the genetic variability of the future progeny could be changed when this component was considered in the OF. For the simulated dataset, the MS outperformed the TS and OCS followed by random mating. In the short-term, MS was more efficient than OCS + inbreeding minimizing in controlling inbreeding under the same genetic gain. However, in the long-term, OCS and MS resulted in similar genetic progress and average inbreeding, under the same weight on coancestry. In general, the mate selection algorithm was efficient and flexible to optimize objective functions accounting for different components, under practical applications in aquaculture breeding.
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Huang, Ying. "Antibiotic Resistance in Aquaculture Production." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1417709599.
Full textCHEMELLO, GIULIA. "Application of nanotechnologies in aquaculture." Doctoral thesis, Università Politecnica delle Marche, 2018. http://hdl.handle.net/11566/252915.
Full textNanotechnology has a great potential to create new materials with enhanced properties through the control and manipulation of the matter at the atomic and molecular level. Nanoparticles (NPs) play an important role in nanotechnology advances, unique NPs characteristics have accelerated the growth in the production of nanoscale materials and the rapid increase of their application in many areas. The major advantages of NPs are represented by their small size and high surface/volume ratio, which make them the key promoters of several industries and research sectors growth. Aquaculture represents the fastest growing food-producing sector in the world and significantly contributes to the world’s supply of fish for human consumption. In order to guarantee a sustainable growth that meets the global needs, aquaculture activity has to overcome some disadvantageous aspects deriving from its own practices, such as the high number of organic compounds in untreated wastewater, the large use of antibiotics and the proliferation of disease vectors. Nanotechnology application could offer different solutions to solve such issues and ensure the sustainable development of aquaculture activity. Thanks to a multidisciplinary approach that includes molecular, chemical and microscopy analysis, this study was able to test the innovative and safe application of two different types of nanotechnology on different aquaculture aspects. Different model organisms (Danio rerio, Sparus aurata, Aedes aegypti, and Escherichia coli) were chosen as the most relevant and useful species to the present research. This doctoral thesis highlighted at first, the great versatility and the safe application of these two types of nanomaterial to solve different aquaculture problems. All the experiments were conducted in a controlled aquatic environment laying the foundations for future studies aiming to a practical consequence in aquaculture activity.
Cross, Stephen F. "Marine finfish and suspended shellfish aquaculture : water quality interactions and the potential for integrated aquaculture." Thesis, University of Stirling, 2005. http://hdl.handle.net/1893/1861.
Full textLegault, Michel. "Détermination des répercussions de l'élevage en pisciculture du saumon atlantique (Salmo salar L.) sur son comportement et ses performances dans une rivière naturelle /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1985. http://theses.uqac.ca.
Full textBélanger, Bernard. "Étude de certains aspects du développement larvaire chez le doré jaune (Stizostedion vitreum vitreum) /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1992. http://theses.uqac.ca.
Full textZhao, Yanlai. "Integrated systems analysis for coastal aquaculture." Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/26824.
Full textRobinson, Georgina. "Microbial-deposit feeder aquaculture bioremediation systems." Thesis, University of Newcastle upon Tyne, 2017. http://hdl.handle.net/10443/3706.
Full textEdattukaran, Margaret P. "Aquaculture in the sultanate of Oman." Thesis, Boston University, 1999. https://hdl.handle.net/2144/28564.
Full textPLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
This thesis is a story of Oman. It will lightly touch the rich fabric of Oman's history. It will chart through some of Oman's modernization as a cohesive Arab state into the new era under the reign of Sultan Qaboos bin Said. The thesis will emphasize Oman's potential as a young entrepreneur, and discuss the pathways and decisions made over the last two decades bringing Oman to the forefront of economic progress and social development while maintaining its cultural heritage. As Oman continues to look for revenue sources other than oil through industrialization, the thesis will focus on Oman's Fisheries industry and discuss the gradual depletion of its marine food resources--a consequence of over-fishing. The thesis will debate whether an aquaculture industry is the next step up from Oman's Fisheries sector and can Oman used the development of its aquaculture sector to increase its revenues. The analysis of an aquaculture sector for Oman will involve evaluating the economic, scientific, environmental and ecological factors dictating the success of entering this industry. It will focus on aquaculture of shrimp and the reasons why Oman would consider using this species to develop its aquaculture sector. The thesis will lay out various approaches to practicing sustainable aquaculture and focus on three potential options to develop the aquaculture sector. This section will canvass the critical factors that should drive the decision making process in selecting the optimal aquaculture approach that will yield Oman the revenue sources it seeks while minimizing any damage to the environment. The three choices are developed with an across the border measuring device with which Oman can evaluate the socio-economical and ecological pros and cons of selecting any of the three options.
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Franco, Sofia Cota. "Aquaculture of stalked barnacles (Pollicipes pollicipes)." Thesis, University of Newcastle upon Tyne, 2014. http://hdl.handle.net/10443/2631.
Full textFarzad, Razieh. "Novel Aquafeed Towards A Sustainable Aquaculture." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/103810.
Full textPHD
Budhabhatti, Jennifer. "Integrating agriculture and aquaculture in Arizona." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185676.
Full textMcIntosh, Dennis. "Reducing the environmental impact of aquaculture." Diss., The University of Arizona, 2002. http://hdl.handle.net/10150/289234.
Full textMELIGRANA, MARINA CONCETTA TERESA. "A scientific contribution towards sustainable aquaculture." Doctoral thesis, Università degli Studi di Camerino, 2019. http://hdl.handle.net/11581/428746.
Full textvan, der Blom Daan Wilhelmus. "Aquaculture in Sweden : Sustainability of land-based recirculation aquaculture as a future alternative for Swedish fish farmers." Thesis, Linköpings universitet, Tema vatten i natur och samhälle, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-94683.
Full textTiu, Laura G. "Assessment and Future Direction of The Ohio State University Aquaculture Program." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1276543251.
Full textClausen, Rebecca J. "Social and ecological transformations of global marine fisheries /." Connect to title online (ProQuest), 2008. http://proquest.umi.com/pqdweb?did=1588418301&sid=4&Fmt=2&clientId=11238&RQT=309&VName=PQD.
Full textTypescript. Includes vita and abstract. Includes bibliographical references (leaves 198-211). Also available online in ProQuest, free to University of Oregon users.
Martins, Patrícia Tavares. "Molecular characterization of microbial communities in aquaculture." Doctoral thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/16504.
Full textMicroorganisms play key roles in fish production and in the maintenance of fish health in aquaculture systems. However, there is still a lack of fundamental knowledge regarding the bacterial composition and diversity of these systems. The general goal of this study is to gain fundamental knowledge on the bacterial communities of different aquaculture systems using molecular techniques. Furthermore, we evaluate the use of molecular methodologies to detect potential fish pathogens and develop a new molecular approach for early detection of a fish pathogen (Photobacterium damselae) in aquaculture systems. In the intensive aquaculture, we assessed the composition of bacterial communities inhabiting recirculating aquaculture systems (RAS) of turbot (Scophthalmus maximus) and sole (Solea solea). Both molecular approaches, DGGE profiles and barcoded-pyrosequencing of 16S rRNA gene fragments, revealed differences between the bacterial communities of both RAS, suggesting that the fish species being cultured promoted a strong effect on water bacterial communities. Several potential pathogenic species were detected, however despite the presence of these pathogens, no symptomatic fish were observed during the study. In this study barcoded pyrosequencing showed to be an unprecedented technique for assessing bacterial communities and reveal potential pathogens. In the second phase of this study, we investigated seasonal patterns of bacterioplankton (free-living and particleassociated bacteria) composition and their putative function in a semi-intensive European seabass (Dicentrarchus labrax) aquaculture system located at Ria de Aveiro. The results indicated that shifts in the bacterioplankton communities are driven by seasonal changes of abiotic characteristics of the estuarine water. Furthermore, the use of bioinformatics tools such as PICRUSt to predict metagenome functional content allowed us a better understanding of microbial quality in this aquaculture system. Given the impact of disease outbreaks in the development of aquaculture sector, we developed a new molecular approach for fast detection of Photobacterium damselae subspecies, responsible for major economic losses in the aquaculture systems in Mediterranean countries of Europe. Specific primers targeting the toxR gene were designed for overall quantification of P. damselae species and specific detection of its subspecies (P. damselae piscicida and P. damselae damselae) based on real time PCR (RT-PCR) and PCR denaturing gradient gel electrophoresis (PCR-DGGE), respectively. This approach showed good specificity for quantification and detection of P. damselae subspecies in estuarine and aquaculture water samples. The molecular approach developed here can contribute for a more effective long-term management of fish health in aquaculture systems.
Os microrganismos têm um papel fundamental no processo de produção de peixes, bem como na manutenção da saúde dos mesmos nos sistemas de aquacultura. Contudo, existe ainda falta de informação acerca da composição e diversidade bacteriana destes sistemas. O objetivo principal deste estudo é adquirir conhecimento fundamental acerca das communidades bacterianas de dois sistemas distintos de aquacultura (sistema intensivo e semiintensivo) recorrendo a técnicas de biologia molecular. Adicionalmente, avaliou-se também a utilização de técnicas de biologia molecular para detetar potenciais bactérias patogénicas e desenvolvemos uma nova abordagem molecular para deteção rápida de uma espécie bacteriana patogénica de peixes (Photobacterium damselae) em sistemas de aquacultura. Na aquacultura intensiva estudou-se a composição das comunidades bacterianas presentes num sistema de aquacultura em recirculação (RAS) com produção de pregado (Scophthalmus maximus) e linguado (Solea solea). As técnicas de biologia molecular utilizadas, eletroforese em gel de gradiente desnaturante (DGGE) e pirosequenciação de fragmentos do gene 16S, revelaram diferenças entre as comunidades bacterianas dos dois sistemas de produção, sugerindo que as espécies produzidas promovem um efeito acentuado nas comunidades bacterianas presentes na água. Várias espécies potencialmente patogénicas foram identificadas, contudo nenhum peixe demonstrou sinais de doença durante o estudo. Neste estudo, a pirosequenciação mostrou ser uma técnica sem precedente para estudar as comunidades bacterianas e revelar potenciais espécies patogénicas. Na segunda fase deste estudo, investigámos padrões sazonais na composição do bacterioplâncton e na sua função num sistema de aquacultura semi-intensivo de produção de robalo (Dicentrarchus labrax) localizado na Ria de Aveiro. Os resultados indicaram que as alterações nas comunidades do bacterioplâncton foram provocadas pelas variações sazonais dos fatores abióticos da água do estuário. Além disso, a utilização de ferramentas bioinformáticas para prever o conteúdo funcional do metagenoma, como o PICRUST, permitiu-nos conhecer melhor a qualidade microbiológica deste sistema de aquacultura. Tendo em conta o impacto dos surtos de doenças no crescimento do sector da aquacultura, desenvolvemos uma nova abordagem utilizando métodos moleculares para uma rápida deteção de subespécies de Photobacterium damselae responsávies por enormes perdas económicas em sistemas de aquacultura nos países mediterrâneos da Europa. Foram desenvolvidos primers específicos utilizando o gene toxR para quantificar a espécie P. damselae e detetar as suas subespécies (P. damselae piscicida and P. damselae damselae) utilizando a técnica de PCR em tempo real (RTPCR) e PCR – eletroforese em gel de gradiente desnaturante (PCR-DGGE), respetivamente. Esta abordagem mostrou elevada especificidade para a quantificação e deteção das subespécies de P. damselae em amostras de água provenientes de um estuário e de um sistema de aquacultura.
Dlaza, Thembinkozi Steven. "Growth of juvenile abalone under aquaculture conditions." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&.
Full textLongdill, Peter. "Environmentally Sustainable Aquaculture: An Eco-Physical Perspective." The University of Waikato, 2008. http://hdl.handle.net/10289/2604.
Full textLinnér, Johan. "Arctic charr growth regulators : implications for aquaculture /." Umeå : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2000. http://epsilon.slu.se/avh/2000/91-576-5778-5.pdf.
Full textramezaniakhmareh, alireza. "Autonomous environmental monitoring probe for aquaculture sites." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-20733.
Full textClarkson, Alexander Ross. "The jurisdiction to regulate aquaculture in Canada." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46455.
Full textTollervey, Alan. "Algal nutrient uptake in recirculating aquaculture systems." Thesis, Heriot-Watt University, 1985. http://hdl.handle.net/10399/1651.
Full textBranfield, G. R. "Thermal charcteristics of a greenhouse for aquaculture." Thesis, Stellenbosch : University of Stellenbosch, 2006. http://hdl.handle.net/10019.1/1794.
Full textSuccessful housing and breeding of exotic animals or plants often requires an environment that is quite different to the ambient conditions present. The current study approached the problem of sub-optimal water temperatures experienced by Central African Bream (Tilapia) housed within a South African greenhouse during winter months. A theoretical and experimental study of fundamental heat and mass transfer processes relevant to an aquacultural greenhouse was conducted. Experimental results were generally in agreement with those of previous researchers; while evaporation tests were found to concur particularly well with an analytical equation developed. The experimental results were used to develop a simple glass greenhouse model to evaluate the expected thermal behaviour during the coldest time of the year. Manipulation of the model revealed that water has the ability to absorb large quantities of solar radiation and regulate temperature fluctuations within such a system, and that the appropriate use of thermal insulation during both the night and day can maintain acceptable water temperatures for extended periods of time. With the conclusions drawn from the experimentation and modelling done, an optimised conceptual greenhouse design was presented, along with associated guidelines and principles for attaining the required water temperatures, and consequently providing the exotic fish specie with a healthy environment.
Jaritkhuan, Somtawin. "Thraustochytrids as a food source in aquaculture." Thesis, University of Portsmouth, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343334.
Full textAnoh, Kouassi Paul. "Pêche, aquaculture et développement en Côte d'Ivoire." Nantes, 2007. http://www.theses.fr/2007NANT3001.
Full textVdovenko, Natalia. "Ukrainian aquaculture steady development in market economy." Thesis, Видавництво СумДУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/10279.
Full textEvans, Oliver Graham Evans. "Modeling the Light Field in Macroalgae Aquaculture." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1542810712432336.
Full textOliveira, Rhaul. "Effects assessment of chemicals used in aquaculture." Doctoral thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/16297.
Full textAquaculture provides food and income for millions of families worldwide being an activity with a high growth rate and with a strong potential for further expansion. Both producers and consumers are interested in a sustainable model of aquaculture development covering social, economic and environmental aspects. Such model implies to cope with the environmental impacts generated by aquacultures. The main objective of this work was to evaluate the use of chemicals applied in aquaculture farms and their harmful effects to aquatic organisms. Since more than 80% of global production of aquatic organisms is concentrated in Southwest Asia, special attention was given to the aquaculture in this region, particularly Thailand. Three different types of aquaculture scenarios were studied: shrimp farms and tilapia farms in cages and in earth ponds. Surveys and monitoring campaigns were conducted in several farms and the fate, use and application patterns of chemicals were identified. In cage farms the results indicated overuse/misuse of antibiotics, in shrimp farms the major group of chemicals used were disinfectants whereas in earth pond farms 1,7α-methyltestosterone (MT) was the most used. The results from the monitoring campaigns showed that the excessive use of chemicals was correlated to contamination of the surrounding environment namely with the antibiotics oxytetracycline (OTC) and enrofloxacin (ENR) in the cage farms, and with MT in the earth pond farms. In the laboratory, ecotoxicity assays were performed with antibiotics, disinfectants and pesticides using organisms belonging to different trophic levels. The disinfectants benzalkonium chloride (BKC), chlorhexidine gluconate (ChD) and glutaraldehyde (GA) were tested. BKC and ChD demonstrated to be very toxic to primary and secondary consumers. Moreover, an approach based on the species sensitivity distributions (SSD) was used to estimate the hazardous concentrations for 5 and 50 % of the species after BKC and GA exposure highlighting the sensitivity of primary producers to BKC exposure (HC5 = 10.8 μg/l). In the case of GA, different trophic levels showed similar sensitivities and a general HC5 = 300 μg/l was obtained. Additionally, a probabilistic environmental risk assessment was performed indicating a PAF (potentially affected fraction) of species > 5% for adverse effects of BKC in effluents and surface water. Concerning pesticides, both trichlorfon (TCF) and ivermectin (IVM) were studied. TCF showed to be extremely toxic to daphnids (48h- LC50 = 0.29 μg/l) and affected the acetilcolinesterase activity in D. magna and D rerio. IVM showed to be acutely toxic to D. rerio life stages (96h-LC50 = 18.5 μg/l for juveniles) and affected their development and biomarkers. In chronic exposures, IVM led to changes in the behaviour and growth of D. rerio juveniles (21d-LOEC < 0.25 μg/l). The antibiotics amoxicillin and OTC were not acutely toxic to aquatic organisms but both induced oxidative stress related enzymes of adults and embryos of D. rerio. Globally, most of the tested chemicals showed to compromise at least a particular group of organisms or sub-lethal parameters, requiring further long term studies so that the environmental risk assessment of these compounds can be refined. Lethal and sub lethal effects obtained to non-target organisms suggest a potential biodiversity loss in the aquatic ecosystems which might, thus, compromise the services provided by the ecosystems in a near future. Since the aquaculture relies directly on these services (e.g. high water quality) to succeed, there is an urgent need of control/education measures both in the use of chemicals in aquaculture and monitoring/mitigation of adverse impacts in natural ecosystems.
A aquacultura fornece sustento para milhões de famílias, sendo uma actividade em crescimento e com um forte potencial de expansão em todo o mundo. Há um interesse por parte de produtores e consumidores em desenvolver modelos sustentáveis de aquacultura abrangendo aspectos sociais, económicos e ambientais. Tais modelos implicam lidar com os impactos ambientais gerados pela aquacultura. O principal objectivo deste trabalho foi estudar o uso de produtos químicos usados nas aquaculturas e avaliar os seus efeitos nocivos para organismos aquáticos. Uma vez que mais de 80% da produção mundial de organismos aquáticos está concentrada no sudoeste da Ásia, foi dada especial atenção à aquacultura nessa região, particularmente na Tailândia. Três diferentes cenários foram considerados: aquaculturas de camarão, aquaculturas de tilápias cultivadas em gaiolas e em tanques escavados no solo. Em cada tipo foram realizados inquéritos e campanhas de monitoramento em várias aquaculturas nas quais foram averiguados o uso, destino e forma de aplicação de químicos. Os resultados indicaram o uso excessivo/inapropriado de alguns compostos, nomeadamente de antibióticos (em aquaculturas em gaiolas), de desinfectantes (em aquaculturas de camarão) e de 1,7α-metiltestosterona (MT) (em aquacultura de tilápias em tanques escavados). Os resultados das campanhas de monitorização mostraram que o uso excessivo de produtos químicos resulta na contaminação do meio ambiente com antibióticos (oxitetraciclina (OTC) e enrofloxacina (ENR)) nas aquaculturas em gaiola, e com MT nas aquaculturas de tilápias em tanques escavados. No laboratório, foram realizados ensaios de ecotoxicidade com antibióticos, desinfectantes e pesticidas usando organismos modelo pertencentes a diferentes níveis tróficos. Foram testados os desinfectantes, cloreto de benzalcónio (BKC), gluconato de clorexidina, e glutaraldeído (GA) sendo que os dois primeiros demonstraram ser muito tóxico para consumidores primários e secundários. Para uma análise integrada foi utilizada uma abordagem baseada nas distribuições de sensibilidade das espécies (DSE) com a qual se estimaram as concentrações perigosas (CP) para 5% e 50% das espécies após e exposição ao BKC e GA. O grupo dos produtores primários foi o grupo mais sensível à exposição ao BKC com CP5% = 10,8 μg/l enquanto para GA não foram encontradas diferenças de sensibilidade entre os grupos tróficos e, assim sendo, um valor geral de CP5% = 300 μg/l foi obtido. Além disso, uma análise probabilística dos riscos ambientais indicou uma fracção de espécies potencialmente afectada (FAPE) pelo BKC > 5% em efluentes e águas superficiais. Os pesticidas estudados foram o trichlorfon (TCF) e a ivermectina (IVM). O TCF foi extremamente tóxico para dafnídeos (48h-LC50 = 0,29 μg/l) e afectou também a actividade de acetilcolinesterase em D. magna e D. rerio. A IVM foi tóxica para adultos, juvenis e embriões de D. rerio (96h- CL50 = 18,5 μg/l para os juvenis) afectando o seu desenvolvimento e actividade de biomarcadores. Em exposições crónicas, IVM causou alterações no comportamento e crescimento em D. rerio juvenis (21d-LOEC <0,25 μg/l). Os antibióticos amoxicilina e OTC apresentam baixa toxidade para os organismos aquáticos, mas ambos induziram enzimas relacionadas estresse oxidativo em adultos e embriões de D. rerio. Em geral, a maioria dos químicos testados apresentaram toxicidade para algum grupo de organismo da cadeia trófica ou tiveram efeito a nível de parâmetros sub-letais, sendo portanto recomendados estudos de exposição crónica para que se possa refinar a avaliação de risco ambiental destes compostos. Os efeitos letais e sub-letais observados nos organismos não-alvo sugerem que pode haver uma perda da biodiversidade nos ecossistemas aquáticos, e assim, comprometer os serviços prestados pelos ecossistemas num futuro próximo. Sendo o sucesso da aquacultura dependente directo destes serviços (por exemplo, água de alta qualidade), há uma necessidade urgente de medidas de controlo/educação, tanto no uso de produtos químicos na aquacultura e monitoramento/mitigação dos impactos negativos destes nos ecossistemas naturais.
Gonzalez-Alanis, Pablo. "The Inactivation of Pathogens in Aquaculture Systems." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/195899.
Full textBrooks, George Benjamin Jr. "Dissolved Nitrogen Compounds in Integrated Aquaculture Effluent." College of Agriculture, University of Arizona (Tucson, AZ), 1992. http://hdl.handle.net/10150/208657.
Full textMateus, Lília Cristiana da Silva. "Phage therapy in aquaculture : use of phage cocktails and lysozyme." Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/13268.
Full textAquaculture is one of the fastest growing food industry sectors in the world in recent years. However, the appearance of pathogenic microorganisms, including multirresistant bacteria, and their dissemination in the environment has become a problem for the aquaculture industry. This means that it is necessary to develop less harmful strategies to the environment to allow a sustainable growth of the aquaculture systems. Phage therapy emerges as a potential alternative to inactivate pathogenic bacteria in aquaculture. The main objective of this study was to assess the efficacy of phage therapy to inactivate fish pathogenic bacteria. The use of phage cocktails and lysozyme was also evaluated on the efficiency of phage therapy. The phage therapy assays were performed with the bacterium Vibrio parahaemolyticus and with three phages produced on this bacterium (VP-1, VP-2 and VP-3). The dynamics of phage-bacteria interaction was characterized in Tryptic Soy Broth through host and phage quantification, respectively by pour plate and by the double-layer agar technique. The three phages were tested alone and in cocktails of two or three phages. The efficiency of the bacterial inactivation by the phages was tested at different lysozyme concentrations (range 0.8 μg mL-1 to 20 mg mL-1). As the selection of bacteriophages is a key factor for the success of phage therapy, the host range, their survival in aquaculture water, as well as the burst size and the explosion time, were determined. The cross-infection was used to determine the phage host range. To determine the survival of the phages in marine water, the double-layer agar technique was used. The burst size and the explosion time were calculated by the one-step growth curve analysis. The use of cocktails of two and three phages was significantly more effective (reduction of 4 log at 2 h of treatment) than the use of the VP-1, VP-2 and VP-3 phages alone (reductions of about 0.6, 0.8 and 2.6 log, at 2 h of treatment respectively for the VP-1, VP-2, and VP-3 phages). The combination of phage plus lysozyme showed a better inhibitory activity when compared with the activity of the phage alone. The VP-1 and VP-2 phages were more efficient to inactivate the Vibrio (reduction of about 4 log after 6 - 8 h treatment), in the presence of high concentrations of lysozyme, than the VP-3 phage. However, the VP-3 phage was more efficient in the presence of low concentrations of lysozyme (reduction of 3.2 log after 2 h of incubation). The results of the cross-infection showed that the phages of Vibrio parahaemolyticus also infect Vibrio anguillarum and Aeromonas salmonicida with high efficiency. The assays of phage survival in aquaculture water showed that the phages remain viable for long time periods (more than 5 - 7 months). The VP-3 phage presented a higher burst size and a shorter latent period (42 and 40 min, respectively) than the other two phages (9 and 15 and 120 min and 90 min, respectively, for the VP-1 and VP-2 phages). In conclusion, the use of phage cocktails appears to be an effective approach to treat vibriosis. Bacterial inactivation is more efficient and occurs earlier when the phage cocktails are used, but their use in vitro does not prevent bacterial regrowth after treatment. However, the use of phage cocktails retarded the regrowth of the bacteria. The application of phages with lysozyme to eliminate or reduce fish pathogenic bacteria in aquaculture can be a promising strategy, namely when less effective phages are available. Besides, the use of phages with a high burst size and a short latent period clearly increase the efficiency of phage therapy.
A aquacultura é um dos setores da área alimentar que mais tem crescido nos últimos anos. No entanto, o aparecimento de microrganismos patogénicos, incluindo bactérias multirresistentes, e a sua disseminação no meio ambiente tornou-se um problema para a indústria de aquacultura. Este facto leva a que seja necessário o desenvolvimento de estratégias menos lesivas para o ambiente de forma a permitir o crescimento sustentável da aquacultura. A terapia fágica surge como uma alternativa potencialmente viável e eficaz para inativar bactérias patogénicas em aquacultura. O principal objetivo deste trabalho consistiu na avaliação da eficácia da terapia fágica para inativar bactérias patogénicas de peixes. Foi avaliado o efeito do uso de cocktails de fagos e de lisozima na eficiência da terapia fágica. Os ensaios de terapia fágica foram realizados com a bactéria Vibrio parahaemolyticus e com três fagos produzidos sobre esta bactéria (VP-1, VP-2 e VP-3). A dinâmica de interação fago-bactéria foi caracterizada em meio de cultura Tryptic Soy Broth através da quantificação do hospedeiro por incorporação e da quantificação dos fagos pela técnica da dupla camada de agar. Os três fagos foram testados isoladamente e em cocktails de dois ou três fagos. A eficiência de inactivação bacteriana pelos três fagos foi testada com diferentes concentrações de lisozima (gama 0,8 μg mL-1 a 20 mg mL-1). Como, para aplicar com sucesso a terapia fágica, é importante ter informação sobre as características dos fagos, a gama de hospedeiros, a sua sobrevivência na água da aquacultura, bem como o seu número e tempo de explosão, foram determinados. Para o estudo da gama de hospedeiros de bacteriófagos usou-se a infeção cruzada. Para determinar a sobrevivência dos fagos na água marinha foi usada a técnica da dupla camada de agar. O número e o tempo de explosão foram determinados através da determinação das curvas de crescimento síncrono. O uso de cocktails de dois e três fagos foi significativamente mais eficaz (redução de 4 log após 2 h de tratamento) do que o uso dos fagos VP-1, VP-2 e VP-3 sozinhos (redução 0,6, 0,8, e 2,6 log para os fagos VP-1, VP-2 e VP-3, respectivamente, após 2 h de tratamento). A combinação de lisozima e fago apresentou melhor atividade inibidora em comparação com a atividade do fago sozinho. Os fagos VP-1 e VP-2 foram mais eficazes na inativação bacteriana (redução de cerca 4 log após 6 - 8 h de tratamento) na presença de altas concentrações de lisozima do que o fago VP-3. No entanto, o fago VP-3 foi mais eficaz na presença de baixas concentrações de lisozima (redução de 3,2 log, depois de 2 h de tratamento). Os resultados da infeção cruzada mostraram que os fagos de Vibrio parahaemolyticus inoculados noutras bactérias infetaram também Vibrio anguillarum e Aeromonas salmonicida, apresentando uma eficiência de infeção elevada. Os ensaios de sobrevivência dos fagos na água de aquacultura mostraram que estes permanecem viáveis por longos períodos de tempo (mais de 5 - 7 meses). O fago VP-3 apresentou um número de explosão maior e um período latente menor (42 e 40 min, respetivamente), do que os outros dois fagos (9 e 120 min e 15 e 90 min, respetivamente, para o fago VP-1 e VP-2). Em conclusão, a utilização de cocktails de fagos parece ser uma abordagem eficaz para o tratamento de vibrioses. A inativação bacteriana é mais eficiente e ocorre mais cedo quando são usados os cocktails de fagos, mas a sua utilização in vitro não impede o recrescimento bacteriano após o tratamento, retardando, no entanto, o recrescimento da bactéria. A aplicação de fagos com lisozima, para eliminar ou reduzir bactérias patogénicas de peixes em aquacultura, pode ser uma estratégia promissora, nomeadamente quando os fagos disponíveis são menos eficientes. A utilização de fagos com um alto número de explosão e um período latente curto aumenta claramente a eficiência da terapia fágica.
Luckhoff, Paul Daniel. "Application of the condition factor in the production of African sharptooth catfish Clarias gariepinus." Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/3421.
Full textIn recent years there has been a renewed interest in the commercial culture of African Sharptooth Catfish. Its robust characteristics and its air breathing capabilities makes the African catfish a good candidate for culture in intensive recirculating systems. In light of the size variation in offspring spawned from undomesticated fish, that may eventually increase cannibalism, suitable methods for the quantification of some production performance parameters such as growth and health measurements need to be established for application in intensive catfish culture. In fish the condition factor (CF) reflects information on the physiological state of the fish in relation to its welfare. This factor is expressed as Fulton’s condition index, or the K-factor. African Sharptooth Catfish fry with average weight of 1.9g ± 0.7867 and average length of 59.375mm ±8.812 were equally allocated into ten 1000L-recirculating tanks. The fish were fed a commercial feed to apparent saturation at a frequency of 5 times per day. Sixteen fish were sampled out of each treatment. Weight (g) and length (mm) of each fish were recorded every seven days over a trial period of 175 days from which Fulton’s condition index K was calculated. Results were analysed for significant differences using one-way ANOVA and Tukey’s pair wise comparison test for the various parameters. Growth parameters (a = -5.083, b = 3.004, R2 = 99.4%) derived from the logarithmic relationship between body weight (W) and standard length (L) indicated an isometric growth through the duration of the trail. No significant differences (P>0.05) in condition factors between treatments were found at the beginning of the trail. Significant differences (P<0.05) were found at the end of the trail for weight between ponds and condition factor between treatments. No significant difference (P> 0.05) between length and treatments were found at the end of the trial. Mean condition factor was 0.856 ± 0.187. By using this information on condition factor for African catfish a K-factor calculation chart for African catfish could be calculated, to be used as a practical measurement tool to measure performance goals on catfish farms.
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.
Full textHunter, Donna-Claire. "A GIS-based decision support tool for optimisation of marine cage siting for aquaculture : a case study for the Western Isles, Scotland." Thesis, University of Stirling, 2009. http://hdl.handle.net/1893/2332.
Full textDu, Plessis Darren Scott. "Chemosensory properties of different Ulva extracts and their effects on Tripneustes gratilla." Bachelor's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/12766.
Full textIdentifying the chemical compounds that attract urchins to seaweeds will increase sea urchin aquaculture efficiency as these compounds can be utilized in the production of artificial feeds enhancing their attractiveness and palatability. This study investigated the chemosensory preferences of the tropical sea urchin Tripneustes gratilla for four crude extracts of Ulva as well as Fresh Ulva and an artificial feed. The four crude extracts of Ulva (Methanolic, Ethanolic, Chloroform and Chloroform-Methanol extracts) were tested by pair-wise chemosensory trials in a Y shaped maze. Urchins were significantly deterred by both the Chloroform and Chloroform- Methanol extracts as well as the solvent controls and artificial feed, however T. gratilla was significantly attracted to both the Methanolic and Ethanolic extracts. These two extracts were tested individually against Ulva and the urchins could not distinguish between Ulva and the extracts. When these two extracts were tested against one another it was found that the urchins were significantly attracted to the Methanolic extract. The Methanolic extract was then added to the artificial feed and significantly improved the feeds attractability. This indicates that these extracts, or the compounds which are responsible for this effect, can be incorporated into artificial feeds thereby making them more attractive to the sea urchin. The percentage yield of Ulva that each solvent extracted was different, although only the Ethanolic extract was found to be significantly different from the Chloroform and Chloroform-Methanol extracts. Future studies are needed to examine the chemical composition of these specific chemosensory compounds. By incorporating these attractive extracts into artificial feeds, South Africa can potentially improve the cultivation success of T. gratilla therefore expanding the economy of the local aquaculture industry through the export of this highly valued seafood product.
Ginindza, Nhlanhla Joseph. "Effect of lipid inclusion levels in aquafeed on carcass composition, quality change during storage and nutrient excretion in dusky kob (Argyrosomus japonicus)." Thesis, Rhodes University, 2016. http://hdl.handle.net/10962/d1020854.
Full textLazo, Zamalloa Oxana. "Development of new products from aquaculture fish species." Doctoral thesis, Universitat de Girona, 2018. http://hdl.handle.net/10803/471460.
Full textLos pasíses de la Unión Europea son consumidores habituales de productos de acuicultura. Es por ello que, se seleccionaron cinco especies con potencial acuícola: Corvina, Lucioperca, Mújol, Seriola y Cherna para el desarrollo de nuevos productos. Este trabajo incluyó opiniones tanto de expertos como de consumidores habituales, incluyendo asñi demandas específicas y preferencias en mercados seleccionados de la UE (Alemania, España, Francia, Italia y Reino Unido. Se desarrollaron distintos prototipos de productos basados en ideas sugeridas y en las propiedades fisicoquímicas y sensoriales de las especies. Seis de estos fueron seleccionados basados en su nivel de procesamiento y mercado. La percepción de consumidores sobre los productos fue evaluada en los 5 países de la UE.La percepción de la imagen de los productos difirió notablemente entre países, así como en la aceptabilidad e intención de compra
Cordero, Francisco Javier Martinez. "Regional economic planning of shrimp aquaculture in Mexico." Thesis, University of Hawaii at Manoa, 2003. http://hdl.handle.net/10125/995.
Full textXu, Zinan. "Isolation, characterisation and application of bacteriophages in aquaculture." Thesis, University of Stirling, 2016. http://hdl.handle.net/1893/23740.
Full textBritz, Peter Jacobus 1959. "Adventures with abalone : aquaculture, poaching, and fishery restoration." Rhodes University, Grahamstown, 2011. http://hdl.handle.net/10962/d1018943.
Full textDorrington, Tarquin. "Recombinant antimicrobials for feed based delivery in aquaculture /." View online ; access limited to URI, 2005. http://0-digitalcommons.uri.edu.helin.uri.edu/dissertations/AAI3188058.
Full textGamboa-Delgado, Julian. "Application of natural stable isotopes in aquaculture nutrition." Thesis, Bangor University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505985.
Full textDuckworth, A. R. "Aquaculture of sponges for production of bioactive metabolites." Thesis, University of Canterbury. Zoology, 2000. http://hdl.handle.net/10092/6672.
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