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The developemnt of fisheries in Lake Victoria is faced with a myriad challenges including overfishing, environmental destruction, disappearance of certain indigenous species and pollution. All these problems can be located within the social, economic and political systems that exists today and in the past. This thesis, ‘Fishers and Fish Traders of Lake Victoria : Colonial Policy and the Development of Fish Production in Kenya, 1880-1978’, argues that the Luo fishers had their own indigenous techniques of fishing, modes of preservation and systems of management that ensured sustainable utilisation of fisheries. The thesis examines the role of the Luo fishers in the sustainable usage of the Lake Victoria fisheries. The British colonial settlers came up with new policies of plantation and commercial farming, taxation and forced labour, all of which encouraged the Luo fishers to partially break with their pre-colonial systems and create new ways of responding to the demands of the colonial state. The study argues that the coming of colonialism and its attendant capitalism introduced new fishing gear as well as new species, such as mbuta, that were inimical to the sustainable utilisation of the Lake Victoria fisheries. The colonial regime also introduced new practices of fisheries management such as scouts, licensing, closed seasons and the numbering of boats, practices geared towards ensuring the commercial production and development of the fisheries. This commercialisation led to cut-throat competition between Asian, European and African fish traders. The coming of independence in 1963 brought some changes, such as the provision of credit facilities, new technology, and attempts by the new African government to more effectively control and manage the fisheries. However, not much changed in terms of policy objectives, and most of the colonial policies remained unchanged. New industries were established around the fisheries, but most remained in the hands of Asians and a few African middlemen. The small-scale fishers continued to struggle against the commercialisation of fishery production, remaining voiceless and marginalised. The study recommends an all inclusive participatory approach to solve the problems currently affecting the Lake Victoria fisheries. / History / DLITT (History)

The developemnt of fisheries in Lake Victoria is faced with a myriad challenges including overfishing, environmental destruction, disappearance of certain indigenous species and pollution. All these problems can be located within the social, economic and political systems that exists today and in the past. This thesis, ‘Fishers and Fish Traders of Lake Victoria : Colonial Policy and the Development of Fish Production in Kenya, 1880-1978’, argues that the Luo fishers had their own indigenous techniques of fishing, modes of preservation and systems of management that ensured sustainable utilisation of fisheries. The thesis examines the role of the Luo fishers in the sustainable usage of the Lake Victoria fisheries. The British colonial settlers came up with new policies of plantation and commercial farming, taxation and forced labour, all of which encouraged the Luo fishers to partially break with their pre-colonial systems and create new ways of responding to the demands of the colonial state. The study argues that the coming of colonialism and its attendant capitalism introduced new fishing gear as well as new species, such as mbuta, that were inimical to the sustainable utilisation of the Lake Victoria fisheries. The colonial regime also introduced new practices of fisheries management such as scouts, licensing, closed seasons and the numbering of boats, practices geared towards ensuring the commercial production and development of the fisheries. This commercialisation led to cut-throat competition between Asian, European and African fish traders. The coming of independence in 1963 brought some changes, such as the provision of credit facilities, new technology, and attempts by the new African government to more effectively control and manage the fisheries. However, not much changed in terms of policy objectives, and most of the colonial policies remained unchanged. New industries were established around the fisheries, but most remained in the hands of Asians and a few African middlemen. The small-scale fishers continued to struggle against the commercialisation of fishery production, remaining voiceless and marginalised. The study recommends an all inclusive participatory approach to solve the problems currently affecting the Lake Victoria fisheries. / History / DLITT (History)

O desafio de se atingir o desenvolvimento sustentável tem levado os sistemas produtivos buscar um equilíbrio entre os aspectos ambientais, econômicos e sociais. Com relação ao uso dos recursos hídricos, a aqüicultura se mostra, no Brasil, como uma atividade economicamente emergente, mas que precisa considerar os aspectos de sustentabilidade em sua produção. O presente trabalho apresenta como objetivo avaliar os potenciais impactos causados pelas atividades de piscicultura e pesque-pague no corpo hídrico, localizado na região de montante da bacia hidrográfica do rio Mogi-Guaçu. Dentre as metodologias de avaliação de impactos ambientais, pode-se destacar a Avaliação do ciclo de vida (ACV) por seu caráter sistêmico, e por isso é utilizada neste trabalho. Para o desenvolvimento do estudo da ACV, foi utilizado o método Environmental Design of Industrial Products - EDIP, alguns métodos de caracterização hídrica na fase de inventário da ACV e uma avaliação qualitativa da introdução de espécies não nativas em uma região. Os resultados deste trabalho estão estruturados de acordo com a metodologia da ACV, aplicada ao pescado advindo de pesque-pague em estudo de caso localizado na região de montante da bacia hidrográfica do rio Mogi-Guaçu. A unidade funcional adotada é a quantidade de kcal contida em um kg de filé de peixe. A utilização da metodologia da ACV na produção animal permite uma avaliação quantitativa dos principais impactos ambientais gerados ao longo do seu ciclo de vida, permitindo acompanhar o comportamento ambiental de cada unidade de processo. A piscicultura se mostra como a maior consumidora dos recursos naturais não renováveis e, seu efluente apresenta um maior potencial de acidificação, em relação ao pesque-pague. O pesque-pague, por sua vez, se mostra como o maior consumidor dos recursos naturais renováveis e seu efluente apresenta um maior potencial de eutrofização, ecotoxicidade e de toxicidade humana. O consumo de energia elétrica é, praticamente, equivalente por parte das atividades de piscicultura e pesque-pague. Qualitativamente, avaliaram-se os potencias impactos decorrentes da introdução de espécies exóticas e alóctones, diagnosticando as principais espécies comercializadas nos pesque-pague, presentes na bacia hidrográfica do rio Mogi-Guaçu. Portanto, as atividades de piscicultura e pesque-pague apresentam potenciais de impactos ambientais negativos ao corpo hídrico da região e precisam adotar medidas para reduzi-los, tais como, redução do uso de substâncias químicas e melhoria da qualidade dos alimentos dos peixes. / The challenge to reach the sustainable development has taken the production systems to search a balance among the environmental, economical and social aspects. For the hydraulic resources consumption, the water based activities in Brazil show as economically emergent, but need to include the sustainable aspects in the production. The goal of this dissertation is to evaluate the potential impacts in the water caused for the activities of fish production and fishery, located in the region of the water basin of the Mogi-Guaçu river. Among the methodologies of environmental impact assessment, the life cycle assessment (LCA) can be focused, because of its systemic aspect and that\'s why it is applied in this work. For the development of the study of this LCA, the methods used are the Environmental Design of Industrial Products - EDIP, some water characterization methods for the inventory analysis of the LCA and a qualitative analysis of the impacts of the inclusion of fishes which are not from the region studied. The results of this work are structured according the LCA methodology, applied to the fish from fish production and fishery in a study case located at the water basin of the Mogi-Guaçu river. The functional unit is the amount of kcal contained in one kg of filet of fish. The use of the methodology of the LCA in the animal production allows a quantitative evaluation of the main environmental impacts caused by its cycle of life, allowing the monitoring of the environmental behavior of each unit of process. The fish production is the highest consumer of the non renewable resources and its water emissions present the highest potential for acidification. The fishery is the highest consumer of renewable resources and its water emissions present the highest potential for nutrient enrichment, ecotoxicity and of human toxicity. The consumption of electric energy is, basically, equal on the activities of fish production and fishery. Qualitatively, it was evaluated the ecological impacts due to the inclusion of fishes which are not from the region studied. Concluding, the activities of fish production and fishery present negative impact potentials for the water quality and some actions should be done to reduce these impacts, as, chemical consumption reductions and a better quality food for the fishes.

There has been heightened interest in the biology of striped bass (Morone saxatilis) because of increased pollution in their native spawning grounds and because of their extensive use in landlocked sport fisheries. Their euryhalinity makes them an excellent species for osmoregulation studies. The objective of this research was to study the rate of adaptation of striped bass gills to sea water (3% salt) after direct transfer from freshwater using biochemical (ion transport enzyme levels), physiological (chloride efflux), and ultrastructural methods. Striped bass have specialized osmoregulatory cells located on the interlamellar and afferent surfaces of their gill filaments as shown by light microscopy (LM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). SEM studies show that apical pit (opening of one or more chloride cells) morphology changes during sea water adaptation, and the number of apical pits increases by 32.5% after two weeks in sea water. Chloride cell size and number, extent of basolateral tubular system, and number of mitochondria per chloride cell appear to increase upon adaptation to sea water. Sodium-potassium adenosine triphosphatase (Na,K-ATPase) activity is maximal on day 3 after transfer to sea water. Studies suggest that cortisol may act as a hormonal mediator for long term adaptation to sea water. The general morphology of both freshwater and sea water adapted fish gills were studied. Preliminary studies indicate that the osmium-dimethylsulfoxide-osmium method can be used to investigate intracellular structural changes in striped bass gills. Since the chloride cells are associated with the afferent surface of the filament, the blood supply to that area is also of great interest in osmoregulation studies. Studies of the gill vasculature using corrosion casting (i.e. filling blood vessels with plastic resins) and SEM indicate that the blood vessel distribution in the striped bass gill is similar to that of other euryhaline species with arterio-arterial, arterio-venous, and nutritive pathways. Blood flow may be controlled at a variety of places by sphincters, shunts and cellular contraction. Correlation of these biochemical, physiological and anatomical measurements will aid in the understanding of the process of adaptation to sea water. (Abstract shortened with permission of author.)

In der vorliegenden Untersuchung wurden erstmals repräsentative Frachtwerte der Emissionen bei der Warmwasserfischproduktion sowie Angaben zur Reinigungsleistung von Siebtrommelfiltern ermittelt. Gemeinsam mit den Wasserbehörden wurde ein überprüfbares System der Dokumentation und Eigenkontrolle der Produktion entwickelt. Die Veranlagung zur Abwasserabgabe erfolgt dabei auf der Grundlage einer modellgestützten rechnerischen Ermittlung der Frachten für die jeweilige Produktionsperiode bzw. das Veranlagungsjahr. Nach dem bisherigen System kann die Erhebung der Abwasserabgabe für die Betreiber von Fischzuchtanlagen um ein Mehrfaches zu hoch sein. Grund sind die auch auf der Basis von 24-Stunden-Mischproben großen Streuungen der Konzentrationsparameter und deshalb sehr stark schwankende Frachten an aufeinanderfolgenden Tagen. Die neue Methode der bilanzmäßigen Berechnung der Abwasserabgabe bedeutete für die untersuchte Anlage eine entscheidende Kostensenkung in der Warmwasserfischproduktion.

Aquaculture plays a critical role in alleviating demand pressures caused by increasing fish consumption and over-exploitation of fishery stocks. While aquatic foods are generally considered low-revenue generators in comparison to other protein-sources, aquaculture products help to support food security, income, and higher standards of living, particularly in developing countries. Decision makers, i.e. policy-makers and farmers, are challenged with the responsibility of planning and conducting aquaculture development in a sustainable way whereby social, environmental and economic goals are simultaneously satisfied. Existing studies that economically evaluate the industry for its current and historical performance, and future development scenarios are invaluable to sustainable planning, but have not been developed in Mexico. This dissertation is comprised of two essays applying Economics and Operations Research theory to regional economic planning for the sustainable development of shrimp farming in northwest Mexico. The analyses are carried out both at the micro (farm) and macro (industry planning and development) levels based on an unbalanced panel of shrimp semi-intensive farms containing primary-source information at pond level for the period 1994, 1996-1998. Using an input distance function approach, the first essay examines total factor productivity (TFP) and technical efficiency (TE) using both traditional (T) and environmentally-adjusted (EA) indicators. The reduction in TFP was determined to be due to a technological regression as reflected by increased input-intensive production technology resulting in an increase in undesirable outputs. The learning curve resulting from a shift from white shrimp to blue shrimp production species resulted in higher FCRs, water exchange and pollution emissions, despite increasing shrimp yields. In all years except 994, EA TE and EA TFP were lower than the traditional TE and TFP scores. TE and TFP had an opposite behavior than yields in this period of time. In order to improve the technological change (TC) component of TFP in light of stable TE scores, increased government assistance in disseminating technological know-how is necessary to improve TFP at a faster rate during the transition period. A sensitivity analysis also revealed the economic feasibility of the implementation of pollution abatement technology based on the calculated shadow price of N and P pollutants at USD $6.35/kg and $8.3/kg respectively. In the second essay, a multi-criteria decision making (MCDM) model was developed to evaluate the sustainable development of shrimp farming in the northwest region of Mexico (States of Sonora, Sinaloa and Nayarit) based on government objectives for aquaculture development in Mexico. Three possible production systems among two species were investigated. The optimal combination of new shrimp farms within 22,500 ha over a five-year period is determined. The planning objectives assumed in the MCDM model are maximization of employment (E), foreign exchange earnings (XG), and economic rent (ER), and total pollution (TOTALPOLL) minimization, subject to land availability and local market demand constraints. Under a preliminary evaluation of single objective optimization, XG and ER maximization produce similar results: USD $888.6 and $322.5 million in foreign exchange earnings and economic rent respectively, and the creation of 6,150 jobs. The MCDM model was implemented using Feasible Goals, which allows for the simultaneous graphical evaluation of decision maps arising from trade-offs among efficient solutions. When fully allocating the available land (22,500 ha), the multiobjective development of the shrimp farming industry produces 7,490 new jobs, ER and XG of USD $204.5 and $497.6 million respectively, with a total pollutant discharge of 2,000 tons. The multiple-criteria optimization strongly favors semi-intensive systems (93% of the total 466 new farms), producing 57,119 tons of shrimp by 2005. The sustainable development of the industry based on the assumptions of this analysis does not suggest intensification of systems. Rather, the results of the MCDM analysis support the claim that semi-intensive farms, which are more common in Mexico, promote sustainability. Based on the findings of each of the essays, it is suggested that production performance indicators are needed on a periodic basis for the evaluation of the shrimp industry of Mexico. Production performance measurements may better assist farmers in the decision-making for industry sustainability and growth. Moreover, direct determination of N and P discharges by farms are recommended in future studies as well as incorporating risk and employing longer time series.

O desafio de se atingir o desenvolvimento sustentável tem levado os sistemas produtivos buscar um equilíbrio entre os aspectos ambientais, econômicos e sociais. Com relação ao uso dos recursos hídricos, a aqüicultura se mostra, no Brasil, como uma atividade economicamente emergente, mas que precisa considerar os aspectos de sustentabilidade em sua produção. O presente trabalho apresenta como objetivo avaliar os potenciais impactos causados pelas atividades de piscicultura e pesque-pague no corpo hídrico, localizado na região de montante da bacia hidrográfica do rio Mogi-Guaçu. Dentre as metodologias de avaliação de impactos ambientais, pode-se destacar a Avaliação do ciclo de vida (ACV) por seu caráter sistêmico, e por isso é utilizada neste trabalho. Para o desenvolvimento do estudo da ACV, foi utilizado o método Environmental Design of Industrial Products - EDIP, alguns métodos de caracterização hídrica na fase de inventário da ACV e uma avaliação qualitativa da introdução de espécies não nativas em uma região. Os resultados deste trabalho estão estruturados de acordo com a metodologia da ACV, aplicada ao pescado advindo de pesque-pague em estudo de caso localizado na região de montante da bacia hidrográfica do rio Mogi-Guaçu. A unidade funcional adotada é a quantidade de kcal contida em um kg de filé de peixe. A utilização da metodologia da ACV na produção animal permite uma avaliação quantitativa dos principais impactos ambientais gerados ao longo do seu ciclo de vida, permitindo acompanhar o comportamento ambiental de cada unidade de processo. A piscicultura se mostra como a maior consumidora dos recursos naturais não renováveis e, seu efluente apresenta um maior potencial de acidificação, em relação ao pesque-pague. O pesque-pague, por sua vez, se mostra como o maior consumidor dos recursos naturais renováveis e seu efluente apresenta um maior potencial de eutrofização, ecotoxicidade e de toxicidade humana. O consumo de energia elétrica é, praticamente, equivalente por parte das atividades de piscicultura e pesque-pague. Qualitativamente, avaliaram-se os potencias impactos decorrentes da introdução de espécies exóticas e alóctones, diagnosticando as principais espécies comercializadas nos pesque-pague, presentes na bacia hidrográfica do rio Mogi-Guaçu. Portanto, as atividades de piscicultura e pesque-pague apresentam potenciais de impactos ambientais negativos ao corpo hídrico da região e precisam adotar medidas para reduzi-los, tais como, redução do uso de substâncias químicas e melhoria da qualidade dos alimentos dos peixes. / The challenge to reach the sustainable development has taken the production systems to search a balance among the environmental, economical and social aspects. For the hydraulic resources consumption, the water based activities in Brazil show as economically emergent, but need to include the sustainable aspects in the production. The goal of this dissertation is to evaluate the potential impacts in the water caused for the activities of fish production and fishery, located in the region of the water basin of the Mogi-Guaçu river. Among the methodologies of environmental impact assessment, the life cycle assessment (LCA) can be focused, because of its systemic aspect and that\'s why it is applied in this work. For the development of the study of this LCA, the methods used are the Environmental Design of Industrial Products - EDIP, some water characterization methods for the inventory analysis of the LCA and a qualitative analysis of the impacts of the inclusion of fishes which are not from the region studied. The results of this work are structured according the LCA methodology, applied to the fish from fish production and fishery in a study case located at the water basin of the Mogi-Guaçu river. The functional unit is the amount of kcal contained in one kg of filet of fish. The use of the methodology of the LCA in the animal production allows a quantitative evaluation of the main environmental impacts caused by its cycle of life, allowing the monitoring of the environmental behavior of each unit of process. The fish production is the highest consumer of the non renewable resources and its water emissions present the highest potential for acidification. The fishery is the highest consumer of renewable resources and its water emissions present the highest potential for nutrient enrichment, ecotoxicity and of human toxicity. The consumption of electric energy is, basically, equal on the activities of fish production and fishery. Qualitatively, it was evaluated the ecological impacts due to the inclusion of fishes which are not from the region studied. Concluding, the activities of fish production and fishery present negative impact potentials for the water quality and some actions should be done to reduce these impacts, as, chemical consumption reductions and a better quality food for the fishes.

This diploma thesis deals with the risk associated with fish production. Selected risks are further taken into account. The risks are further described and addressed using the FMEA matrix. The thesis contains a mathematical model that solves the optimal population of the pond in order to maximize profits. The model includes fixed input parameters, which includes the price of hatchery material and the market price of fish. Furthermore, the model contains random input parameters that are limited by the intervals and includes the growth coefficient and the size of the population in the pond. The optimization model is based on simulated data, which are based on real data and statistically determined estimates. The used data are processed into tables in MS Excel for better visualization. GAMS software is used for software implementation of the model.

In der vorliegenden Untersuchung wurden erstmals repräsentative Frachtwerte der Emissionen bei der Warmwasserfischproduktion sowie Angaben zur Reinigungsleistung von Siebtrommelfiltern ermittelt. Gemeinsam mit den Wasserbehörden wurde ein überprüfbares System der Dokumentation und Eigenkontrolle der Produktion entwickelt. Die Veranlagung zur Abwasserabgabe erfolgt dabei auf der Grundlage einer modellgestützten rechnerischen Ermittlung der Frachten für die jeweilige Produktionsperiode bzw. das Veranlagungsjahr. Nach dem bisherigen System kann die Erhebung der Abwasserabgabe für die Betreiber von Fischzuchtanlagen um ein Mehrfaches zu hoch sein. Grund sind die auch auf der Basis von 24-Stunden-Mischproben großen Streuungen der Konzentrationsparameter und deshalb sehr stark schwankende Frachten an aufeinanderfolgenden Tagen. Die neue Methode der bilanzmäßigen Berechnung der Abwasserabgabe bedeutete für die untersuchte Anlage eine entscheidende Kostensenkung in der Warmwasserfischproduktion.