959 resultados para Fisheries Management
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Pós-graduação em Ciências Biológicas (Zoologia) - IBRC
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AbstractThis study evaluates the effectiveness of two fish passes at two hydropower dams (Canoas I and II) in the Upper Parana basin, which form part of a cascade of three reservoirs. Fish from 12 migratory species (3089 specimens) were captured during their ascending, reproductive migration and were tagged with hydrostatic tags. The recapture data (294 specimens over two consecutive years) showed that there is a strong tendency for the maintenance of ascending migration through reservoirs with fish passes but with differences in migratory activity within the same species. No eggs, larvae or juveniles of these species were found in samples collected over 5 years in the reservoirs above the fish passes. These data suggest that fish passes have contributed to the restoration of the migratory routes of adult fish but that in the absence of suitable spawning or nursery habitats for these species; they probably act as ecological traps and do not contribute to the recruitment of the species.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The pirarucu (giant red fish), Arapaima gigas (Cuvier), (Arapaimidae) is among the diverse fish resources of Amazonia which are threatened by over-exploitation. Little is known about the biology of this species despite its commercial importance. The present paper provides indirect information about the length-frequency structure of the stock which was estimated by sampling its tongue bone in craft shops and weighing fresh manias (processed fish product) in fish markets since these were the only remaining recognizable features of the fish. The length-frequency reconstruction was carried out using a regression analysis calculated by utilizing individuals caught in experimental fishing.
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The pirarucu (giant red fish), Arapaima gigas (Cuvier), (Arapaimidae) is among the diverse fish resources of Amazonia which are threatened by over-exploitation. Little is known about the biology of this species despite its commercial importance. The present paper provides indirect information about the length-frequency structure of the stock which was estimated by sampling its tongue bone in craft shops and weighing fresh manias (processed fish product) in fish markets since these were the only remaining recognizable features of the fish. The length-frequency reconstruction was carried out using a regression analysis calculated by utilizing individuals caught in experimental fishing.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Máster en Gestión Sostenible de Recursos Pesqueros
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Máster en Gestión Sostenible de Recursos Pesqueros
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Máster en Gestión Sostenible de Recursos Pesqueros
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[ES] El concepto de gobernanza del sector pesquero ha evolucionado notablemente a nivel mundial en los últimos años, conectando a instituciones económicas, administrativas, políticas y sociales, legitimando y equilibrando las interacciones entre todos los actores del sector, dentro de un marco de dimensión local, nacional e internacional. En este trabajo se describe el contexto en el que se inscribe la gobernanza del sector pesquero grancanario en la actualidad y los actores involucrados en dicha actividad, así como sus perfiles sociales, funciones e interacciones. Se analiza la gestión pesquera desde el punto de vista de la agilidad en sus funciones de cada una de las partes implicadas en la misma, en base al estudio de las competencias y cometidos otorgados por ley, el papel real ejercido por cada una y la percepción y concepción de las razones que conducen a la actual crisis del sector. La información analizada se obtuvo a partir de una revisión bibliográfica y la realización de entrevistas y encuestas a distintas personalidades relacionadas con la actividad pesquera. Se proponen medidas generales para promover un mejor funcionamiento organizativo del sector y fomentar su cohesión. Este trabajo proporciona una visión general de la gobernanza de la pesca en Gran Canaria, como punto de partida para la generación de políticas de gestión que integren la dinámica y la complejidad del sector a partir de un mejor conocimiento del mismo.
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Máster en Gestión Sostenible de los Recursos Pesqueros
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Stocks’ overexploitation and socio-economic sustainability are two major issues currently at stake in European fisheries. In this view the European Commission is considering the implementation of management plans as a means to move towards a longer-term perspective on fisheries management, to consider regional differences and to increase stakeholder involvement. Adriatic small pelagic species (anchovies and sardines) are some of the most studied species in the world from a biologic perspective; several economic analysis have also been realised on Italian pelagic fishery; despite that, no complete bioeconomic modelization has been carried out yet considering all biologic, technical and economic issues. Bioeconomic models cannot be considered foolproof tools but are important implements to help decision makers and can supply a fundamental scientific basis for management plans. This research gathers all available information (from biologic, technologic and economic perspectives) in order to carry out a bioeconomic model of the Adriatic pelagic fishery. Different approaches are analyzed and some of them developed to highlight potential divergences in results, characteristics and implications. Growth, production and demand functions are estimated. A formal analysis about interaction and competition between Italian and Croatian fleet is examined proposing different equilibriums for open access, duopoly and a form of cooperative solution. Anyway normative judgments are limited because of poor knowledge of population dynamics and data related to the Croatian fleet.
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The South Georgia region supports a large biomass of krill that is subject to high interannual variability. The apparent lack of a locally self-maintaining krill population at South Georgia means that understanding the mechanism underlying these observed population characteristics is essential to successful ecosystem-based management of krill fishery in the region. Krill acoustic-density data from surveys conducted in the early, middle and late period of the summers of 2001 to 2005, together with krill population size structure over the same period from predator diet data, were used with a krill population dynamics model to evaluate potential mechanisms behind the observed changes in krill biomass. Krill abundance was highest during the middle of the summer in 3 years and in the late period in 2 years; in the latter there was evidence that krill recruitment was delayed by several months. A model scenario that included empirically derived estimates of both the magnitude and timing of recruitment in each year showed the greatest correlation with the acoustic series. The results are consistent with a krill population with allochthonous recruitment entering a retained adult population; i.e. oceanic transport of adult krill does not appear to be the major factor determining the dynamics of the adult population. The results highlight the importance of the timing of recruitment, especially where this could introduce a mismatch between the peak of krill abundance and the peak demand from predators, which may exacerbate the effects of changes in krill populations arising from commercial harvesting and/or climate change.