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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Analysis of The Net Benefit form Doing Protection Measures of Nature Resources of Inshore Fishing in Taiwan, R.O.C.

Tsuey, Luo 31 August 2004 (has links)
Though it bears favorable natural environment, the development of Taiwan coastal fishery is blocked by many factors. Among which, the exhausted fishery resources stays at the top, resulting from the various pollution, over-fishing and illegal fishing etc.. In addition, subject to the WTO regulations, the fiercer competition facing fishing products is another factor. To improve this situation, the Fisheries Administration takes many measures, in order to protect the fishery resources, realize the sustained development and increase the income of fishermen. This research is to, by the method of policy analysis and the principle of the fisheries economics, discuss the protection measures on Taiwan coastal fishery resources in recent years. Taking the policy planning into consideration, other than restoring the cultivation and re-productivity of the fishery resources, the diverse development is also concerned. While the analysis of the fish output, production value, unit fishing effort and the income of the fishermen presents a well performance. This research is designed to discusses, with the method of cost-benefit-analysis, the executive benefits of the measures in 2000, 2001 and 2002, with the results showing the proportion of the profits to the cost over 1 and the net profits also speaking for the well performance. Suggestions: 1. The policies for the coastal fisheries should be pertinence of the concrete targets, in order to avoid the decrease in profits resulting form the conflict regulations. The harmony among regulations is important for realization of the diverse development. 2. More detailed statistics is necessary for objective assessment of the executive performance. 3. The results attained always lag the policy application, so that the timing and the durative of the execution cannot be neglected or all efforts may be in vain. And experts are necessary to supervise and assess if the running cost of the policy enforcement is regarded as the scale economy, and such performance should survive the changes in personnel and the decrease in outlay.
2

A Study on Fishery Resource Management in Taiwan: A Law Enforcement Aspect

Lu, Chih-Chiang 06 September 2011 (has links)
Taiwan, surrounded by sea and rich in marine resources, is one of the most important fishery states in the world. Fishery activity, one of the ways for humans to obtain food, provides jobs and economic benefits for fishery personnel. Plentiful fishing resources given from the nature have been considered to be unlimited for a long time. However, with the spread of fishery knowledge and the promotion of techniques, unrestrained fishing and damaged fishery environment have caused exhausted crisis to fishing resources. It is finally recognized by humans that marine resources are not inexhaustible. Hence, humans should take necessary measures to conserve and manage fishing resources in order to utilize fishing resources sustainably. After the approval of UNCLOS in 1982, coastal states have the rights and bear the obligations to manage and utilize the fishing resources in the waters under their jurisdiction. UNCLOS itself is also the norm of management in maritime fishing resources. Owing to international responsibility, Taiwan not only signs agreements with other states and fishery organizations proactively, but also revises domestic fishery laws and regulations to implement the conventions. Taking necessary management measures is insufficient for the conservation of fishing resources that the maritime law enforcement needs to be strengthened. Consequently, illegal fishing activities can be clamped down and fishing resources can be conserved as well. Recently, the security of fishermen working in our sea area is under threat due to escalated fishing activities violating to the regulation, increased fishing boats from mainland China crossing the boundary, and disputes among neighboring countries on the overlap areas of EEZ. For growing emphasis on the conservation and management of fishery resources, this study will analyze the legal system of fishing resources conservation and inspect the situations of law enforcement by the fishery and coast guard authorities. Moreover, advanced steps will be discussed to provide suggestions to improve the law enforcement system and conserve maritime fishing resources under considerations of important fishery states¡¦ management and law enforcement measures.
3

Estimação do índice de abundância de um estoque pesqueiro com estrutura de correlação espacial: uma abordagem bayesiana / Estimation of the indice of abundance of fish stocks considering a structure of spatial correlation: a bayesian approach

Pereira, Júlio César 31 March 2009 (has links)
Dados de captura e esforço estão entre as informações mais importantes a serem obtidas na pesca. Muitas vezes, ao se fazer a avaliação de um estoque pesqueiro, são utilizados índices de abundância baseados na captura por unidade de esforço. Como esses índices são utilizados para a tomada de decisão sobre a regulamentação e distribuição da atividade pesqueira, é importante conhecer quais índices se aplicam melhor em diferentes cenários, bem como a melhor maneira de estimá-los. Na literatura, alguns trabalhos tratam as diferentes localizações geográficas onde ocorrem as pescarias como covariável, considerando que esse é todo o efeito espacial presente nos dados. Entretanto, é possível que ainda haja efeitos remanescentes de segunda ordem. Assim, seria importante utilizar modelos que permitam capturar essa estrutura de correlação espacial. Outros trabalhos, que utilizam métodos geoestatísticos, consideram a razão entre a captura e o esforço como sendo a única variável resposta. Nesse tipo de abordagem, não se considera a relação que pode existir entre a variável esforço em uma localização s qualquer e a captura em outra localização s0 e vice-versa (a covariância cruzada). Esses fatos motivaram a elaboração dos dois artigos apresentados nesta tese. No primeiro artigo foram comparadas estimativas de três índices de abundância relativa, considerando-se dois métodos distintos: 1. usando apenas dados observados nos locais de ocorrência de pesca; 2. usando o método proposto neste artigo, que consiste em se obter estimativas após a interpolação da captura e do esforço nos locais não observados, através de um modelo ajustado aos dados. Para a comparação dos métodos de estimação e das estimativas dos três índices, foram simulados dados de esforço e captura em diferentes cenários. O estudo de simulação realizado mostrou que o segundo método de estimação melhora as estimativas dos índices, principalmente quando se tem correlação entre esforço e captura e correlação espacial. Mostrou ainda, que as estimativas do índice CPUE1, apresentam, em geral, melhores resultados para os diferentes cenários analisados. No segundo artigo, foi realizado um estudo de simulação para comparar estimativas de um índice de abundância relativa, baseado na captura por unidade de esforço considerando-se o ajuste de um modelo geoestatístico univariado para a razão entre captura e esforço, e um bivariado, em que são modelados conjuntamente a captura e o esforço. As estimativas obtidas após o ajuste dos dois modelos apresentaram resultados muito próximos, indicando que não há vantagem em usar o modelo bivariado na estimação do índice, para os cenários analisados. / Catch and effort data are among the most important information to be obtained in fishing. Often when making an assessment of fish stocks, are used indices of abundance based on catch per unit effort. Because these indices are used for decision on regulation and distribution of fishing activity, it is important to know which indices are better applied in different sceneries and the best way to estimate them. Some studies in the literature deal with different geographical locations where occur the fisheries as a covariate, considering that this is the whole spacial effect in the data. However, it is possible that there are still remaining second-round effects. It would be important use models that allow to capture spatial structure of correlation. Other works, using geostatistical methods, consider the ratio between catch and effort as the only response variable. In this approach, it is not considered the relationship that exist between the variable effort in a location s and the catch in any other location s0 and vice versa (the cross-covariance). These facts motivated the development of the two articles in this thesis. In the first article we compared estimates of three indices of relative abundance, considering two distinct methods: 1. using only data observed in places where the fishing occurr, 2. using the proposed method in this article that is to get estimates after the capture and interpolation efforts in places not observed, through a model fitted to data. To compare the estimation methods and the estimates of the three indices were simulated data of effort and catch on different scenarios. The simulation study showed that the second estimation method improves the estimates of the indices, especially when there is correlation between effort and catch and spatial correlation, and that estimates of the indice CPUE1, present, in general, better results for different scenarios analyzed. In the second article was done a simulation study to compare estimates of an indice of abundance based on the catch per unit effort considering the fit of a geostatistical univariate model for the ratio between catch and effort and a bivariate model, where the catch and effort are modeled together. The estimates obtained after the two fitted models showed very similar results, indicating that there is no advantage in using the bivariate model in the estimation of the indice to analyzed scenarios.
4

A computable dynamic bioeconomic model of the optimal utilisation and management of South Africa's renewable marine resources : a case study of the hake fishery.

Saville, Adrian David. January 1997 (has links)
No abstract available. / Thesis (Ph.D.)-University of Natal, Durban,1997.
5

Estimação do índice de abundância de um estoque pesqueiro com estrutura de correlação espacial: uma abordagem bayesiana / Estimation of the indice of abundance of fish stocks considering a structure of spatial correlation: a bayesian approach

Júlio César Pereira 31 March 2009 (has links)
Dados de captura e esforço estão entre as informações mais importantes a serem obtidas na pesca. Muitas vezes, ao se fazer a avaliação de um estoque pesqueiro, são utilizados índices de abundância baseados na captura por unidade de esforço. Como esses índices são utilizados para a tomada de decisão sobre a regulamentação e distribuição da atividade pesqueira, é importante conhecer quais índices se aplicam melhor em diferentes cenários, bem como a melhor maneira de estimá-los. Na literatura, alguns trabalhos tratam as diferentes localizações geográficas onde ocorrem as pescarias como covariável, considerando que esse é todo o efeito espacial presente nos dados. Entretanto, é possível que ainda haja efeitos remanescentes de segunda ordem. Assim, seria importante utilizar modelos que permitam capturar essa estrutura de correlação espacial. Outros trabalhos, que utilizam métodos geoestatísticos, consideram a razão entre a captura e o esforço como sendo a única variável resposta. Nesse tipo de abordagem, não se considera a relação que pode existir entre a variável esforço em uma localização s qualquer e a captura em outra localização s0 e vice-versa (a covariância cruzada). Esses fatos motivaram a elaboração dos dois artigos apresentados nesta tese. No primeiro artigo foram comparadas estimativas de três índices de abundância relativa, considerando-se dois métodos distintos: 1. usando apenas dados observados nos locais de ocorrência de pesca; 2. usando o método proposto neste artigo, que consiste em se obter estimativas após a interpolação da captura e do esforço nos locais não observados, através de um modelo ajustado aos dados. Para a comparação dos métodos de estimação e das estimativas dos três índices, foram simulados dados de esforço e captura em diferentes cenários. O estudo de simulação realizado mostrou que o segundo método de estimação melhora as estimativas dos índices, principalmente quando se tem correlação entre esforço e captura e correlação espacial. Mostrou ainda, que as estimativas do índice CPUE1, apresentam, em geral, melhores resultados para os diferentes cenários analisados. No segundo artigo, foi realizado um estudo de simulação para comparar estimativas de um índice de abundância relativa, baseado na captura por unidade de esforço considerando-se o ajuste de um modelo geoestatístico univariado para a razão entre captura e esforço, e um bivariado, em que são modelados conjuntamente a captura e o esforço. As estimativas obtidas após o ajuste dos dois modelos apresentaram resultados muito próximos, indicando que não há vantagem em usar o modelo bivariado na estimação do índice, para os cenários analisados. / Catch and effort data are among the most important information to be obtained in fishing. Often when making an assessment of fish stocks, are used indices of abundance based on catch per unit effort. Because these indices are used for decision on regulation and distribution of fishing activity, it is important to know which indices are better applied in different sceneries and the best way to estimate them. Some studies in the literature deal with different geographical locations where occur the fisheries as a covariate, considering that this is the whole spacial effect in the data. However, it is possible that there are still remaining second-round effects. It would be important use models that allow to capture spatial structure of correlation. Other works, using geostatistical methods, consider the ratio between catch and effort as the only response variable. In this approach, it is not considered the relationship that exist between the variable effort in a location s and the catch in any other location s0 and vice versa (the cross-covariance). These facts motivated the development of the two articles in this thesis. In the first article we compared estimates of three indices of relative abundance, considering two distinct methods: 1. using only data observed in places where the fishing occurr, 2. using the proposed method in this article that is to get estimates after the capture and interpolation efforts in places not observed, through a model fitted to data. To compare the estimation methods and the estimates of the three indices were simulated data of effort and catch on different scenarios. The simulation study showed that the second estimation method improves the estimates of the indices, especially when there is correlation between effort and catch and spatial correlation, and that estimates of the indice CPUE1, present, in general, better results for different scenarios analyzed. In the second article was done a simulation study to compare estimates of an indice of abundance based on the catch per unit effort considering the fit of a geostatistical univariate model for the ratio between catch and effort and a bivariate model, where the catch and effort are modeled together. The estimates obtained after the two fitted models showed very similar results, indicating that there is no advantage in using the bivariate model in the estimation of the indice to analyzed scenarios.
6

Determinação de um índice de sustentabilidade no estuário do rio Vaza- Barris, litoral sul do Estado de Sergipe

Foppel, Ernesto Frederico da Costa 28 February 2018 (has links)
Fundação de Apoio a Pesquisa e à Inovação Tecnológica do Estado de Sergipe - FAPITEC/SE / Worldwide, marine and coastal fisheries are experiencing declining catches as the result of both natural and anthropogenic processes. The use of inadequate fishery techniques, overfishing, the disposal of solid waste, contamination of the water, and poor administration by public agencies all contribute to the decline in natural fishery resources. Riverside communities often depend on fishery resources, and when these resources become scarce, they abandon fishing to find work in other locations. These communities are also vulnerable to the loss of their identity through processes such as the spread of holiday homes and increasing tourism. The present study determined the Index of Sustainability (IS) of three riverside communities of the Vaza-Barris estuary on the southern coast of the Brazilian state of Sergipe. The study was based on a combination of two complementary approaches. One method is an adaptation of the MESMIS (Framework for the Evaluation of Natural Resource Management Systems) tool, which is based on the measurement of indices, while the other was proposed by Calório, and is also based on indices, although with emphasis on the compilation of guidelines for the support of public policy. In the target communities, semistructured interviews were conducted using qualitative-quantitative questions and a snowball sampling technique. The IS measured by the MESMIS approach indicated “medium sustainability” (50.54), with the lowest value (9.55) being recorded for the “increase in the number of fishers”. Other negative economic indices included “regulatory measures” (10.90) and “mean income of fishers”, which was below the minimum wage (11.54). The environmental indices with the lowest values were solid waste found in the river (29.14) and prohibited fishing equipment (36.06). Based on the Calório approach, the community of Pedreiras had the lowest index, and one of the principal factors determining its performance was the almost complete absence of tourism at this locality, and the lack of alternative sources of income related to this activity. In the final analysis, the recommended policy measures included the training of community members in fishery techniques, as well as alternative occupations, the more effective monitoring and regulation of fishery activities throughout the estuary, and projects of environmental education designed to instruct the local population on the disposal of solid waste. / A pesca seja ela marítima ou costeira realizada em todo o mundo, vem demonstrando sinais de declínio populacional e as causas podem ser de origem natural ou antrópica. O uso de petrechos de pesca inadequados, o desrespeito à reposição dos estoques, o descarte de resíduos sólidos, contaminação das águas e a má gestão por parte dos órgãos públicos são exemplos que vem levando ao processo de redução dos recursos pesqueiros na natureza. As comunidades ribeirinhas são explotadoras de recursos pesqueiros e devido a sua escassez, podem vir a abandonar a atividade, sujeitando-se a trabalhos alheios a sua origem. Além disso, essas comunidades estão propensas à perda de identidade devido à chegada de veranistas e consequentemente a exploração turística, entre outros problemas. O presente trabalho teve como objetivo determinar um Índice de Sustentabilidade (IS) em três comunidades ribeirinhas no estuário do rio Vaza-Barris, litoral sul do estado de Sergipe. O método proposto foi à soma de duas metodologias: a primeira se trata de uma é adaptação do MESMIS (Marco para Avaliação de Sistemas de Manejo de Recursos Naturais) ferramenta utilizada para a mensuração de indicadores e a segunda foi adaptada da proposta por Calório que também trabalha com indicadores, mas deu ênfase no direcionamento de políticas públicas. Nas comunidades especificadas foram feitas entrevistas semiestruturadas, com perguntas quali-quantitativas e esquema de coletas através do método bola de neve. O resultado encontrado foi que o Índice de Sustentabilidade de acordo com a metodologia MESMIS encontra-se em “média sustentabilidade” (50,54) destacando-se entre os indicadores sociais “o aumento do número de pescadores” com o pior valor registrado (9,55). Nos indicadores econômicos destacaram-se negativamente as “ações de fiscalização” (10,90) e “renda média do pescador” que ficou abaixo do salário mínimo (11,54). Já os indicadores ambientais tiveram os resíduos sólidos (29,14) encontrados no rio e o uso de petrechos proibidos (36,06) como os piores avaliados. Com base na metodologia de Calório, o povoado que teve o pior rendimento foi à comunidade de Pedreiras e um dos principais motivos para isso foi a quase nula atividade turística na localidade e as poucas oportunidades de trabalho alternativo para esta. Ao final as ações de políticas públicas recomendadas foram direcionadas a capacitação do pescador na atividade de pesca, assim como alternativas de renda, demanda maior na fiscalização em todo o estuário em relação à atividade pesqueira e projetos que visem à educação ambiental quando ao descarte de resíduos sólidos. / São Cristóvão, SE
7

Caractéristiques biologiques spatialisées et influence des stratégies individuelles dans la gestion des ressources halieutiques : une approche par les jeux différentiels / Biological characteristics and spatial influence of individual strategies in the management of fishery resources : an approach based on differential games

Idda, Corinne 15 July 2014 (has links)
Une grande partie de la ressource halieutique est, à ce jour, surexploitée, voire menacée d’extinction. Il est donc nécessaire de gérer cette ressource de manière à assurer la viabilité du secteur économique de la pêche. L’objectif de ce travail est d’étendre et de compléter les modèles existant dans la littérature économique sur le sujet qui visent à analyser les effets de différentes stratégies de préservation de la ressource sur le profit du secteur de la pêche. Ces travaux souffrent en effet de deux limites principales.D’une part, ils mettent principalement en avant les caractéristiques biologiques de la ressource dans l’espace et leurs travaux se limitent généralement à la détermination du niveau de pêche qui assure le rendement soutenable maximal. Cependant, d’un point de vue économique, ces travaux sont limités puisqu’ils ne prennent pas en compte les interactions stratégiques entre agents.D’autre part, concernant les politiques de gestion de la ressource halieutique dans l’espace, peu de travaux intègre les stratégies individuelles des agents pour évaluer les impacts de ces règlementations sur l’état des stocks. De plus, en ce qui concerne les aires marines protégées, les travaux existant se concentrent sur les impacts de ce type de mesures sur les stocks de ressource et leur approche ne permet pas d’évaluer l’impact de la taille d’une aire marine protégée.Il est donc important d’élargir l’analyse dans deux directions. Tout d’abord, Nous allons tenter d’améliorer les travaux existants en y intégrant les stratégies des pêcheurs dans le cadre d’un secteur oligopolistique, (structure de marché représentative du secteur de la pêche), tout en prenant en compte les caractéristiques biologiques en termes de dispersion pour savoir dans quelle mesure ces différents aspects influencent les perspectives de préservation.Enfin, nous nous intéresserons, dans le même cadre d’analyse, aux politiques de gestion des ressources halieutiques pour évaluer leur efficacité. / Much of the fishery resource is, to date, overexploited even endangered. It is therefore necessary to manage this resource to ensure the sustainability of the fishery’s economic sector. The aim of this work is to extend and complete the existing models in the literature on the topic which aim for analyze the effects of different strategies for resource conservation benefit of the fishery sector. Indeed, these studies suffer from two main limitations.On the one hand, they put forward mainly the biological characteristics of the resource in space and their works are generally limited to the determination of the fishing level which provides the maximum sustainable yield. However, from an economic point of view, these works are limited, as they do not take into account the strategic behavior between agents.On the other hand, concerning the management policies of fishery resources in space, a few studies integrate agents’ individual strategies to evaluate the impacts of these regulations on the stocks state. In addition, with regard to marine protected areas, existing works focus on the impact of such measures on resources stock and their approach does not allow evaluating the impact of the size of a marine reserve.It is therefore important to extend the analysis in two directions. Firstly, we will try to improve existing works on integrating fishermen strategies in an oligopolistic sector (market structure representing the fishery sector), while taking into account the biological characteristics in terms of dispersion, to investigate in which extent these aspects influence the preservation prospects.Then, we focus, in the same analytical framework, the fishery resources management policies to evaluate their effectiveness.

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