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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.
91

Feeding and digestion in the phyllosoma larvae of ornate spiny lobster, Panulirus ornatus (Fabricius) and the implications for their culture

Johnston, Matthew D January 2007 (has links)
[Truncated abstract] In this thesis I investigated the ingestive and digestive morphology and digestive physiology during development of phyllosomata of the ornate spiny lobster, Panulirus ornatus. This knowledge was applied to develop a suitable formulated diet to be fed in combination with Artemia or used as a supplement to reduce production costs. The major impediment to closure of the life cycle of spiny lobsters has been an inadequate dietary regime, stemming from a lack of information on their feeding biology and ingestive and digestive capabilities. Of all spiny lobster species, P. ornatus is the best candidate for aquaculture in Australia having the shortest larval development phase (46 months) and fast growth rate, attaining 1 kg within 2 years of hatch. Currently, Artemia and fresh feeds such as mussel are used routinely as hatchery feeds. However, the development of a formulated diet that is palatable and delivers the correct balance of nutrients is seen as a highly attractive and cost effective alternative. An appropriate formulated diet for aquaculture of phyllosomata of spiny lobsters can be developed more effectively when the ingestive and digestive morphology, physiology and feeding behaviour are fully understood. ... Partial replacement trials revealed that P. ornatus phyllosoma are stimulated to feed by visual cues. Furthermore, 75% of the entire Artemia ration can be replaced with a formulated diet without having any adverse effects on survival and growth of early-stage phyllosomata. Weaning P. ornatus phyllosomata onto 100% formulated diet during stages II-III resulted in reduced survival but demonstrated that diets containing 44-50% crude protein with a diverse range of marine protein sources provides optimum survival and growth. This thesis has identified both physical and nutritional components that will contribute to the successful development of formulated diets for aquaculture of this species. Ultimately, although formulated diets are ingested and provide more than adequate survival when fed in combination with Artemia during early ontogeny, greater success and the possibility of totally replacing Artemia may occur after day 32 (stage IV) due to an increased efficiency to capture and manipulate larger sized particles externally and a greater capacity to triturate prey and sort and filter particles internally. Furthermore, a general increase in specific activity of digestive enzymes at stage IV suggests the possibility of a greater capacity to digest and assimilate nutrients.
92

Comparison of three survey methods applied to the recreational rock lobster fishery of Western Australia

Baharthah, Tara. January 2007 (has links)
Thesis (M.Sc.)--Edith Cowan University, 2007. / Submitted to the Faculty of Computing, Health and Science. Includes bibliographical references.
93

Co-management and the Eastport lobster fishery /

Blundon, Joy January 1999 (has links)
Thesis (M.M.S.), Memorial University of Newfoundland, 1999. / Bibliography: leaves 52-53.
94

Impactos sócios-ambientais de Marambaias para a pesca de lagosta: o caso de Ponta Grossa, Icapuí-Ce / Economic and environmetal impacts of artificial reefs for lobster fishing: the case of Ponta Grossa, Icapuí-Ce

Nascimento, Robson Cabral do January 2006 (has links)
Nascimento, Robson Cabral do. Impactos sócios-ambientais de Marambaias para a pesca de lagosta: o caso de Ponta Grossa, Icapuí-Ce,. 2006. 86 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Programa Regional de Pós-Graduação em Desenvolvimento e Meio Ambiente - PRODEMA, Fortaleza-CE, 2006 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-04-18T16:28:37Z No. of bitstreams: 1 2006_dis_rcnascimento.pdf: 1083746 bytes, checksum: e2ca9f3df8602f4a74304f22528b0fed (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-04-18T16:29:03Z (GMT) No. of bitstreams: 1 2006_dis_rcnascimento.pdf: 1083746 bytes, checksum: e2ca9f3df8602f4a74304f22528b0fed (MD5) / Made available in DSpace on 2016-04-18T16:29:03Z (GMT). No. of bitstreams: 1 2006_dis_rcnascimento.pdf: 1083746 bytes, checksum: e2ca9f3df8602f4a74304f22528b0fed (MD5) Previous issue date: 2006 / The indiscriminate lobster fisheries has been causing stock reduction, minimizing the effectiveness of artesian fisheries and reducing the income of fishing communities, stimulating even more the overfisheries and the capture of undersized lobsters. As an alternative, the community has been implanting artificial reefs, which are structures where microorganisms settle forming a feeding chain, therefore serving as an attractor for commercial species. At Ponta Grossa community, Icapuí – CE, the use of artificial reefs exclusively for lobster fishing was an initiative taken by some of the local fishermen in 2002. With the successful result of the first fisheries at the artificial reefs, a fast increase on the number of artificial occurred, what made the control of their use very difficult. So far, there a very few information about the effects of artificial reefs on the lobster fishery at Ceará State. In order to provide information to organize the use of these structures there is an urgent need to determine the real effectiveness of the initiative in terms of increasing fisheries and to evaluate social, economic and environmental impacts. The artificial reefs for lobster are build of wood measuring 30 cm in height and 6 m2 of área. The launching of the structures was carried through by the fishing in depths between 3 and 13 m. A total of 36 fishermen took part in this study. Data from 484 fishing activities were analyzed during the years of 2003 (year I) to 2005 (year III), being 280 of them in shallow waters (less than 5 m of depth) and 204 in waters deeper than 5m. These depths intervals were chosen arbitrarily. The data were used to determine the amount of lobster captured in relation to the fishery effort (CPUE), the average lobster’s size and the percentage of lobsters above the legal commercial size. The socio-economic analysis was performed using the profit earned by each fishing activity. The environmental impact was performed by G.U.T. method. The results showed that the average size of captured lobsters (Panulirus argus) was below legal minimum size (13 cm). The amount of lobster captured in relation to the fishery effort was above the historical average of Ceará State, showing the efficiency of these structures to increase productivity, however the values for the average profit per fisherman decreased significantly during the second and third years of the study, suggesting that in the first year occurred just a concentration of lobster stock in the same area. In the first year the most significant negative impacts were the over exploitation of the stocks and the occurrence of juvenile lobster on the catches. The most significant positive impacts were the increase of local fishery, the formation of new habitats, the development of new technologies and the possibility to develop scientific research. In Year III the most significant negative impacts were the presence of juvenile lobsters in the catches, the reduction of fisheries biomass, the over exploitation and the reduction on the amount of local fishery. In relation to positive impacts, the reduction of the fisheries using gill nets and the possibility for scientific research were the most evident. In conclusion, the artificial reefs have not played a sustainable role because the main result was just the concentration of stocks in the same area. The use of artificial reefs should follow a management plan and respect the law restriction on capturing juvenile lobsters. / A pesca indiscriminada de lagostas vem causando a diminuição dos estoques, minimizando a efetividade da pesca artesanal e reduzindo a renda de comunidades pesqueiras, estimulando a ainda mais a sobrepesca e a captura de indivíduos juvenis. Como alternativa, vem sendo implantadas as marambaias, que são estruturas para fixação de microorganismos aquáticos para a formação de cadeia trófica, servindo como atrator para espécies de interesse comercial. Na praia de Ponta Grossa, Icapuí- CE, o uso de marambaias voltadas prioritariamente para a pesca de lagosta partiu de pescadores locais em 2002. Com o sucesso das primeiras pescarias, houve “bloom” de marambaias instaladas e dificuldade de controle sobre o uso das mesmas. Sobre o litoral cearense ainda são poucas as informações sobre o efeito de marambaias para a atração de lagostas. Visando dar subsídios ao ordenamento de uso dessas estruturas, urge a necessidade de se determinar a efetividade para o aumento da produtividade e avaliar os impactos socioeconômicos e ambientais. Marambaias para lagosta são estruturas de madeira com 30 cm de altura da base e 6 m2 de área. O lançamento foi realizado pelos pescadores em profundidades entre 3 e 13 m. Participaram deste estudo 36 pescadores. Foram analisados dados de 484 pescarias nos anos de 2003 (Ano I) a 2005 (Ano III), sendo 280 em profundidades <5 m e 204 em profundidades >5 m. A escolha dos intervalos de profundidade foi arbitrária. Estes dados serviram para a determinação da captura por unidade de esforço (CPUE), do tamanho médio das lagostas e do percentual de lagostas com tamanho comercial. A avaliação socioeconômica foi realizada pelo cálculo do rendimento das pescarias. A avaliação do impacto ambiental foi realizada pelo método G.U.T.. O comprimento médio das lagostas (Panulirus argus) ficou abaixo do tamanho mínimo determinado por lei (13 cm). As CPUE´s ficaram acima da média histórica do Ceará, indicando a eficiência destas estruturas para o aumento da produtividade, embora os valores de receita média por pescador tenham sofrido significativa queda na renda no segundo e terceiro anos, indicando que houve apenas concentração do estoque nas pescarias no primeiro ano. No Ano I, os impactos negativos mais significantes foram a sobreexploração do estoque e a incidência de lagostas juvenis nas capturas. Os impactos positivos mais significantes foram o incremento da pesca local, a criação de novos habitats, o desenvolvimento de tecnologias e o fomento a pesquisa científica. No Ano III, os impactos negativos mais significantes foram a incidência de lagostas juvenis nas capturas, a redução da biomassa de pescado, a sobreexploração de estoques pesqueiros e a redução da pesca local. Quanto aos impactos positivos, destacam-se a redução das pescarias com rede de emalhar e o fomento a pesquisa científica. Concluise que as marambaias não atuaram de forma sustentável, pois funcionaram apenas como concentradoras de estoque. Recomenda-se que o uso de marambaias deve obedecer a um plano de manejo e respeitar as normativas de proibição da captura de juvenis de lagosta.
95

The conservation genetics of ecologically and commercially important coral reef species

Truelove, Nathan January 2014 (has links)
Identifying the extent to which coral reef species are connected by dispersal is a fundamental challenge for developing marine conservation strategies. Many coral reef species are relatively sedentary as adults, yet have a pelagic larval phase where larvae can potentially be widely dispersed by ocean currents. This thesis focuses on the role of ocean currents in driving spatially explicit patterns of population connectivity among ecologically and commercially important coral reef species by combining research tools from population genetics, oceanography, and biophysical modeling. Despite the substantial differences among the life histories of each coral reef species in this thesis, some similarities in connectivity patterns were found among all species. The results of the kinship and genetic outlier analyses consistently found high levels of connectivity among distant populations separated by hundreds to thousands of kilometers. Despite the high levels of connectivity among distant populations, there was substantial variation in gene flow among the populations of each species. The findings of this thesis highlight the importance of international cooperation for the sustainable management of ecologically and commercially important coral reef species in the Caribbean. In conclusion, the findings of this thesis suggest that marine conservation strategies should conservatively plan for uncertainty, particularly since the many of ecological and physical drivers of connectivity among coral reef species in the Caribbean remain uncertain.
96

Negotiated Living: An Ethno-Historical Perspective of Punta Allen

McRae, David Thomas 12 1900 (has links)
Situated within the jurisdiction of the Municipality of Tulum and within the Sian Ka'an Biosphere gives the village of Punta Allen a distinctive agency in determining their role in the on-going development of tourism in the region that is not given to other communities in the state. This unique circumstance facilitates a dialogue between the reserve, the municipality, and the business cooperatives of Punta Allen that produce a negotiated living. Through the negotiations with the reserve and Tulum, the lobster fishing and tourism cooperatives are given the opportunity to have a relatively significant role in determining the future of Punta Allen in regards to tourism.
97

Optimization studies on chitin extraction from crustacean solid wastes

Tetteh, Antonia Yarbeh January 1991 (has links)
No description available.
98

Permit pricing in fisheries with transferable effort controls

Plamadeala, Victoria 01 January 2004 (has links)
No description available.
99

A sustentabilidade da pesca da lagosta na visão do pescador artesanal: um estudo de caso / The sustainability of the lobster fishing in sight of the fisherman: a case study

Vieira, Marcília Marques January 2007 (has links)
VIEIRA, Marcília Marques. A sustentabilidade da pesca da lagosta na visão do pescador artesanal: um estudo de caso. 2007. 90 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia de Pesca, Fortaleza-CE, 2007 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-20T12:02:43Z No. of bitstreams: 1 2007_dis_mmvieira.pdf: 572342 bytes, checksum: 42b52facb523f9ae2ea4977a2af6c68f (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-20T12:03:07Z (GMT) No. of bitstreams: 1 2007_dis_mmvieira.pdf: 572342 bytes, checksum: 42b52facb523f9ae2ea4977a2af6c68f (MD5) / Made available in DSpace on 2016-07-20T12:03:07Z (GMT). No. of bitstreams: 1 2007_dis_mmvieira.pdf: 572342 bytes, checksum: 42b52facb523f9ae2ea4977a2af6c68f (MD5) Previous issue date: 2007 / A sustentabilidade dos recursos naturais, inclusive pesqueiros, tem sido pauta de discussão há décadas. A sensação de infinito, que por vezes temos do mar, parece que se estende aos recursos ali encontrados. O saber científico e o saber popular convergem num só alerta: sem medidas urgentes e realmente eficazes, a lagosta pode se acabar como atividade econômica. O Ceará ainda é o principal estado da federação na exportação do crustáceo, mas o item, que por muito tempo esteve em primeiro lugar na pauta de exportações do Estado, hoje está na quarta colocação. Este estudo consiste em verificar junto aos pescadores artesanais da Praia das Frexeiras, BeberibeCe, a visão dos mesmos sobre a Sustentabilidade da pesca da Lagosta. Para alcançar esta finalidade, utilizou-se dados de origem primária, obtidos através de questionários envolvendo as questões referentes aos aspectos pessoais e sociais da família, profissionais, bens de produção, defeso da lagosta e segurodesemprego,contemplando a população de 33 pescadores, todos beneficiários do Programa de Seguro Desemprego ao Pescador Artesanal. Fez-se a gravação de entrevistas, que relatavam o pensamento deles sobre o assunto e utilizou-se também a observação científica. Conclui-se que os pescadores artesanais da Praia das Frexeiras em Beberibe-Ce, são possuidores de um senso crítico formador de opinião sobre a Sustentabilidade da pesca da Lagosta. Torna-se então necessário, que haja uma união de esforços para que num período de curto, médio e longo prazo sejam definidas ações de cunho prático, visando assim, a reestruturação do setor lagosteiro e por conseqüência, a sustentabilidade da atividade
100

Áreas de pesca de lagosta: uma caracterização utilizando geoprocessamento e veículo de operação remota (R.O.V.) / Areas of lobster: a characterization using GIS and remotely operated vehicle (ROV)

Colares, Maria Cecília da Silva January 2009 (has links)
COLARES, Maria Cecília da Silva. Áreas de pesca de lagosta: uma caracterização utilizando geoprocessamento e veículo de operação remota (R.O.V.). 2009. 60 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrária, Departamento de Engenharia de Pesca, Fortaleza-CE, 2009 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-20T12:14:22Z No. of bitstreams: 1 2009_dis_mcscolares.pdf: 7543614 bytes, checksum: 1fb114e9296c6db79c0055a6218ee800 (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-20T12:14:37Z (GMT) No. of bitstreams: 1 2009_dis_mcscolares.pdf: 7543614 bytes, checksum: 1fb114e9296c6db79c0055a6218ee800 (MD5) / Made available in DSpace on 2016-07-20T12:14:37Z (GMT). No. of bitstreams: 1 2009_dis_mcscolares.pdf: 7543614 bytes, checksum: 1fb114e9296c6db79c0055a6218ee800 (MD5) Previous issue date: 2009 / The Continental Shelf is a dynamic constantly studied by different areas, from the Marine Geology, Engineering, Fisheries, Oceanography, Biology etc passing by, including the first submerged region, extending from the coast toward the ocean basin, with an average slope 1: 1000, and an average width of about 40 nautical miles (70 km). The fishing resources available on the continental shelf are many, so that fishing is an extremely profitable activity for some countries. In Brazil there could be different since the country has in its geography over 8000 km of coastline and 200 miles are available for fishing. The Northeast, especially the state of Ceará had since the 70s until the 90s, a great weight on the scales of fish export business, powered by the main appeal and high commercial value abroad: the lobster. This work was carried out on the Continental Shelf eastern state of Ceara, aiming to characterize points of lobster fishing, using a methodology that combines digital image processing, point sampling of sediments, diving and shooting through a ROV (Remotely Operated Vehicle). The results are shown in the form of thematic maps all data and field processed in the laboratory, integrated, showing a perfect applicability of R. O. V. this crossover design and its efficiency in capturing images of the sampled points, thus proving the feasibility and safety of this methodology for future work. We conclude that the application of methodologies cross was effective and achieved its objectives, demonstrating that the use of ROV was essential and definitely better than scuba diving, leading us to adopt it in future in new projects, together with the sampling point or not, depending on the environment to be characterized and defined parameters. / A Plataforma Continental é um ambiente dinâmico constantemente estudado por diversas áreas, desde a Geologia Marinha, Engenharia de Pesca, Oceanografia, passando pela Biologia etc, compreendendo a primeira região submersa, estendendo-se da costa em direção à bacia oceânica, com uma declividade média de 1: 1000, e uma largura média de aproximadamente 40 milhas náuticas (70 km). Os recursos pesqueiros disponibilizados na plataforma continental são muitos, fazendo com que a pesca seja uma atividade extremamente lucrativa para alguns países. No Brasil não poderia ser diferente já que o país apresenta em sua geografia mais de 8000 Km de costa e as 200 milhas náuticas disponíveis para a pesca. O Nordeste, principalmente o Estado do Ceará teve desde a década de 70 até os anos 90, um grande peso na balança comercial de exportação de pescados, alavancados pelo principal recurso e de maior valor comercial no exterior: a lagosta. Esse trabalho foi realizado na Plataforma Continental Leste do Estado do Ceará, visando a caracterização de pontos de pesca de lagosta, utilizando uma metodologia que reúne processamento digital de imagem, amostragem pontual de sedimentos, mergulho autônomo e filmagem através de um R.O.V. (Remotely Operated Vehicle). Os resultados são mostrados em forma de mapas temáticos com todos os dados obtidos em campo e processados em laboratório, integrados, mostrando a perfeita aplicabilidade do R. O. V. nessa metodologia cruzada e sua eficiência na captura das imagens dos pontos amostrados, comprovando assim a viabilidade e segurança dessa metodologia para futuros trabalhos. Concluimos que a aplicação das metodologias cruzadas foi eficaz e atingiu os objetivos propostos, demonstrando que a utilização do R.O.V. foi essencial e definitivamente melhor que o mergulho autônomo, levando-nos a adotá-lo, futuramente em novos projetos, em conjunto com a amostragem pontual ou não, dependendo do ambiente a ser caracterizado e dos parâmetros definidos.

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