940 resultados para Stocks Repurchase


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Adult salmon and sea trout rod catches in the River Wyre have been subject to considerable variability over the years. Annual rod catches ranging from 6 to 401 have been reported since records began in 1905. It has long been suspected that the physical nature of the catchment, combined with anthropogenic influences, has resulted in a deleterious effect on the Wyre fishery. Acidification problems in the head water streams (Marshaw Wyre and Tarnbrook Wyre) have been reported and are thought to threaten salmon juvenile survival. The construction of Abbeystead Reservoir and an increased tendency towards rapidly rising water levels during storms (flashiness) 1 are thought to have a significant impact on spawning gravel quality and quantity, both of which are thought to be deteriorating. As part of an overall desire to maintain and improve the migratory salmonid population in the River Wyre, this project has been commissioned to investigate remedial action which may improve and enhance spawning success, leading to an eventual improvement in the status of adult stocks. The primary objective is to establish whether the quantity and/or quality of available spawning gravels are limiting migratory salmonid productivity. The investigations undertaken confirm the general observation that useable spawning gravels appear to be in short supply in the River Wyre, and may be the limiting factor influencing returning adult stock.

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This investigation was carried out to provide information on fish stocks and angling activity during 1997 in relation to the drought and, in particular, flows as influenced by Time Limited Licences. These abstractions will be for review in 1999. This report extends and updates the data presented for 1996. Fish population surveys (including eels) were undertaken on the main river and selected tributaries. Angler caught brown trout were examined, angler catch data have been reviewed, and observations by Environment Agency fisheries staff collated. It appeared that in River Wharfe both the fish populations and individual fish appeared to be in good condition and limited changes had occurred since the 1996 survey.

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Genetic analysis, using single locus probes for genomic DNA, revealed that the juvenile Atlantic salmon populations in the Rivers Leven, Rothay and Troutbeck were related but genetically distinct. This genetic differentiation is greater than might be expected (by comparison with other salmon populations in the UK) and it is recommended that no action is taken which might promote genetic exchange between the three rivers. Thus, future fisheries management practices should treat the salmon from each site as separate genetic stocks. It is unlikely that any attempts to encourage fish currently spawning in the River Leven (downstream of Windermere) to utilize the upper catchment will be successful. The faster growth rate of juvenile salmon in the River Leven, compared with the River Rothay, probably results from a difference in temperature between the inflowing streams and the main outflow of Windermere. Precocious sexual maturation of some male parr was found in all three populations but the incidence (13-33%) is well within the range reported for other waters. Because of their enhanced growth rate, it is likely that some of the precocious males in the River Leven were 0+ fish. A very high incidence of hybridization (>18%) between Atlantic salmon and brown/sea trout was found in Troutbeck but not in the other rivers. Mitochondrial DNA analysis of these hybrids revealed them to be the product of several, independent cross-fertilizations involving both sexes of both species. The implications of this finding are discussed in relation to the availability of suitable spawning sites in Troutbeck.

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Many of British rivers hold stocks of salmon (Salmo salar L.) and sea trout (Salmo trutta L.) and during most of the year some of the adult fish migrate upstream to the head waters where, with the advent of winter, they will eventually spawn. For a variety of reasons, including the generation of power for milling, improving navigation and measuring water flow, man has put obstacles in the way of migratory fish which have added to those already provided by nature in the shape of rapids and waterfalls. While both salmon and sea trout, particularly the former, are capable of spectacular leaps the movement of fish over man-made and natural obstacles can be helped, or even made possible, by the judicious use of fish passes. These are designed to give the fish an easier route over or round an obstacle by allowing it to overcome the water head difference in a series of stages ('pool and traverse' fish pass) or by reducing the water velocity in a sloping channel (Denil fish pass). Salmon and sea trout make their spawning runs at different flow conditions, salmon preferring much higher water flows than sea trout. Hence the design of fish passes requires an understanding of the swimming ability of fish (speed and endurance) and the effect of water temperature on this ability. Also the unique features of each site must be appreciated to enable the pass to be positioned so that its entrance is readily located. As well as salmon and sea trout, rivers often have stocks of coarse fish and eels. Coarse fish migrations are generally local in character and although some obstructions such as weirs may allow downstream passages only, they do not cause a significant problem. Eels, like salmon and sea trout, travel both up and down river during the course of their life histories. However, the climbing power of elvers is legendary and it is not normally necessary to offer them help, while adult silver eels migrate at times of high water flow when downstream movement is comparatively easy: for these reasons neither coarse fish nor eels are considered further. The provision of fish passes is, in many instances, mandatory under the Salmon and Freshwater Fisheries Act 1975. This report is intended for those involved in the planning, siting, construction and operation of fish passes and is written to clarify the hydraulic problems for the biologist and the biological problems for the engineer. It is also intended to explain the criteria by which the design of an individual pass is assessed for Ministerial Approval.

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In order to improve the habitat of the Rivers Ribble and Hodder in the north west of England it is necessary to assess existing fish stocks. To assist the Ribble Fisheries Association a test census of stock has been made on the rivers Hodder and Ribble. The fish have been taken by electro fishing techniques. The following fish were collected over six days in September 1965: dace, chub, grayling, eel, salmon and trout. This short report summarises the findings of the survey.

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Esta dissertação tem como objeto o estudo da relação estabelecida entre a indústria farmacêutica e a assistência farmacêutica no âmbito do SUS. O objetivo é avaliar como estão sendo feitas as compras de medicamentos para os programas de assistência farmacêutica básica para hipertensão, diabetes e asma e rinite. A captura de dados foi realizada nas Secretarias de Saúde do estado e do município do Rio de Janeiro. Realizou-se comparação dos preços unitários dos medicamentos adquiridos no estado, no município do Rio de Janeiro e no Banco de Preços em Saúde (BPS), no período de janeiro de 2000 a dezembro de 2006. Em alguns momentos foram utilizados dados da Revista ABCFARMA, sobre preços unitários do mercado varejista. A pesquisa tornou possível registrar que o Estado do Rio de Janeiro compra medicamentos a um preço unitário mais alto do que aqueles praticados pela prefeitura e pelo Banco de Preços em Saúde. A hipótese apresentada é que o preço unitário mais alto se deve às inúmeras compras emergenciais realizadas, que estimulam os fornecedores a compensar o risco com preços maiores. Como a maioria dos fornecedores é distribuidora de medicamentos, elas estariam onerando os preços unitários, pois tiveram problemas no passado com o cumprimento da dívida pelo estado. Segundo autoridades estaduais da Secretaria de Estado de Saúde, esta situação indesejável está sendo superada através de uma nova forma de aquisição de medicamentos. A prefeitura do Rio de Janeiro, por outro lado, tem realizado as compras de medicamentos por licitações na modalidade concorrência. Esta forma possibilitou a aquisição de medicamentos a preços inferiores aos outros entes pesquisados. A maioria dos fornecedores da prefeitura é a própria indústria de medicamentos, o que, em princípio, torna o preço mais baixo. Conclui-se, então: que o Estado do Rio de Janeiro passou por crises de desabastecimento ou abastecimento irregular dos programa de assistência farmacêutica básica, o que contribuiu para a elevação dos preços praticados; e que a prefeitura do Rio de Janeiro tem conseguido comprar medicamentos em condições mais favoráveis que o governo de estado.

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O estoque de matéria orgânica de superfície refere-se a todo material orgânico decomposto ou em decomposição sobreposto ao solo mineral, bem como ao material orgânico misturado às partículas minerais do horizonte A. Este serve como indicador da funcionalidade e integridade de ecossistemas florestais quando o analisamos sob a perspectiva das "Formas de Húmus". Nesta perspectiva o material orgânico se presenta como disposto em camadas internas que variam no peso e espessura de acordo com a atuação dos agentes decompositores locais, e expressa a ciclagem de nutrientes que se dá a partir dos dois principais processos que sintetizam e/ou modulam o funcionamento dos ecossistemas, a produção e a decomposição da matéria orgânica. O modelo de formas de húmus segue uma classificação desenvolvida na Europa que não se aplica perfeitamente às áreas tropicais pela alta variabilidade de ambientes. Estima-se que fatores locais e particulares como características edáficas, estrutura e composição da vegetação, relevo e o microclima podem distorcer esta classificação e diferir significativamente do modelo global. Esta pesquisa buscou o refinamento deste modelo, buscando entender de que modo a pluviosidade efetiva (chuva que atravessa a copa das árvores e chega ao solo), como fenômeno de natureza microclimática, se relaciona com o estoque de matéria orgânica de superfície (sob a perspectiva das formas de húmus) em ambiente de floresta ombrófila montanhosa urbana.Para tal foram executadas análises físicas sobre o estoque de matéria orgânica de superfície, monitoramento da pluviosidade efetiva com pluviômetro experimentais adaptados para esta demanda e análises químicas sobre a água da chuva após lixiviação da matéria orgânica. Foi montada uma estrutura composta de quinze pluviômetros experimentais em uma encosta florestada no Parque Nacional da Tijuca (Rio de Janeiro - RJ) e instalação de pluviômetros eletrônicos em ambientes de céu aberto em áreas adjacentes a esta encosta pertencentes à área do parque. Os resultados indicam que da chuva que cai na floresta, cerca de 15% é interceptada pelas copas e o restante, parte é interceptada pela matéria orgânica do solo. A camada MFB (ou H) é a que retém mais água, indicando que, florestas que a decomposição é rápida no processo de fragmentação e lenta na mineralização, terão mais água retida no estoque de matéria orgânica. As diferentes camadas vão nutrir o solo de maneira diferenciada quando este processo deriva da lixiviação, como o cálcio que é liberado em a maior quantidade pelas camadas mais fragmentadas como a F e a MFB, o potássio e magnésio têm maior disponibilização quando deriva da camada L, indicando que durante este processo estes nutrientes são mais consumidos do que liberados. Foi perceptível que o sódio é bastante abundante na chuva antes mesmo de atingir a matéria orgânica, confirmando estudos anteriores. A utilização deste sistema proposto de pluviômetros experimentais possibilitou entender como esta estratificação interna do estoque de matéria orgânica de superfície acumula água, pois os métodos tradicionais não se baseiam no modelo de formas de húmus, e possibilitou ainda, o a análise do processo de lixiviação e liberação de nutrientes para o solo.

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The document gives an account of the activities carried out during the year 1988 by the Lake Kariba Fisheries Research Institute and includes individual reports of the various projects conducted during the year. They include: the Zambia/Zimbabwe Lake Kariba Fisheries Research and Development Project; a comparative study of genetic growth determinance of Limnothrissa miodon; a comparative study of consumption rates and preference for some species of aquatic macrophytes by Tilapia rendalli; an evaluation of inshore stocks, and external variables causing variation in composition abundance and distribution; Willards cage-culture pilot project; and, aspects of the ecology of the phytobenthic communities in Lake Kariba - PhD thesis.

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The report is presented under the following headings: Officer-in-charge's report; The Zambia/Zimbabwe SADCC Lake Kariba Fisheries Research and Development Project; Comparative study of growth of Limnothrissa miodon (Boulenger) in Lake Kariba; An analysis of the effects of fishing location and gear on kapenta catches on Lake Kariba; Hydro-acoustic surveys in Lake Kariba; The pre-recruitment ecology of the freshwater sardine Limnothrissa miodon (Boulenger) in Lake Kariba; Report on short course in zooplankton quantitative sampling methods held at the Freshwater Biology Laboratory, Windermere from 19 to 30 November 1990; Report on training: post-graduate training - Humberside Polytechnic, UK; Postharvest fish technology in Lake Kariba, Zimbabwe; and assessment of the abundance of inshore fish stocks and evaluating the effects of fishing pressure on the biology of commercially important species and ecological studies on Synodontis zambezensis .

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The report provides catch records for the Kapenta and inshore fisheries in the Zimbabwean waters of Lake Kariba for the year 1994. Kapenta usually constitute about 90% of the total catch from Lake Kariba; for statistical purposes catches are recorded for the 5 hydrological basins - Mlibizi, Binga, Sengwa, Bumi and Kariba. Whereas kapenta represent a unit stock which is harvested by both Zimbabwe and Zambia, the artisanal fishery exploits inshore species which generally occupy water less than 10m deep along the shoreline, considered to be 2 separate stocks. The main species in the inshore fishery are Oreochromis mortimeri, Sargochromis codringtonii, Tilapia rendalli, Labeo altivelis, Hydrocynus vittatus, Mormyrus longirostris, Clarias gariepinus and Synodontis zambezensis.

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The report provides catch records for the Kapenta and inshore fisheries in the Zimbabwean waters of Lake Kariba for the year 1995. Kapenta usually constitute about 90% of the total catch from Lake Kariba; for statistical purposes catches are recorded for the 5 hydrological basins - Mlibizi, Binga, Sengwa, Bumi and Kariba. Whereas kapenta represent a unit stock which is harvested by both Zimbabwe and Zambia, the artisanal fishery exploits inshore species which generally occupy water less than 10m deep along the shoreline, considered to be 2 separate stocks. The main species in the inshore fishery are Oreochromis mortimeri, Sargochromis codringtonii, Tilapia rendalli, Labeo altivelis, Hydrocynus vittatus, Mormyrus longirostris, Clarias gariepinus and Synodontis zambezensis.

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The report provides catch records for the Kapenta and inshore fisheries in the Zimbabwean waters of Lake Kariba for the year 1996. Kapenta usually constitute about 90% of the total catch from Lake Kariba; for statistical purposes catches are recorded for the 5 hydrological basins - Mlibizi, Binga, Sengwa, Bumi and Kariba. Whereas kapenta represent a unit stock which is harvested by both Zimbabwe and Zambia, the artisanal fishery exploits inshore species which generally occupy water less than 10m deep along the shoreline, considered to be 2 separate stocks. The main species in the inshore fishery are Oreochromis mortimeri, Sargochromis codringtonii, Tilapia rendalli, Labeo altivelis, Hydrocynus vittatus, Mormyrus longirostris, Clarias gariepinus and Synodontis zambezensis.

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The report provides catch records for the kapenta (Limnothrissa miodon) and inshore fisheries in the Zimbabwean waters of Lake Kariba for the year 1997. Kapenta usually constitute about 94% of the total catch from Lake Kariba; for statistical purposes catches are recorded for the 5 hydrological basins - Mlibizi, Binga, Sengwa, Bumi and Kariba. The kapenta, which occupy the open pelagic waters of the lake, represent a unit stock which is harvested by both Zimbabwe and Zambia; the artisanal fishery exploits inshore species which generally occupy water less than 10m deep along the shoreline. The Zambian and Zimbabwean inshore fisheries may therefore be considered to be exploiting 2 separate stocks. The main species in the inshore fishery are Oreochromis mortimeri, Sargochromis codringtonii, Tilapia rendalli, Labeo altivelis, Hydrocynus vittatus, Mormyrus longirostris, M.anguilloides and Clarias gariepinus.

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As part of an overall desire to maintain and improve the migratory salmonid population in the River Wyre, a project was commissioned to investigate remedial action which may improve and enhance spawning success and lead to an eventual improvement in the status of adult stocks. The report, titled "River Wyre Salmon and Sea Trout Spawning Habitat Restoration/Creation Project", concluded that usable spawning gravels appeared to be in short supply in the River Wyre catchment and may be the limiting factor influencing the returning adult stock, as juvenile nursery habitat was not found to be limiting. This report looks at gravel enhancement schemes to improve River Wyre salmon and sea trout spawning habitat restoration. It examines methods for gravel enhancement schemes: mechanical cleaning and construction of gravel addition structures. Includes sites figures of sites identified for enhancement.

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In 1996 a Strategy for the Management of Salmon in England and Wales was launched by the National Rivers Authority setting out objectives for the management of Salmon fisheries. These objectives are to be met through local Salmon Action Plans which are to be produced for each of the 68 principal salmon rivers in England and Wales by December 2003. A consultation document was produced for the river Wyre and released publicly during October 2003. This document: • Determined an egg deposition figure of 1.27 million eggs which would allow maximum gain from the fisheries • Raised a number of issues which are though to limit existing salmon production. • Identified actions which may be undertaken by the Environment Agency and other bodies to improved stocks. The document looks at the issues in the consultation document and also highlights some important changes to historic egg deposition rates following further analysis of the data. Some of the major issues addressed in the plan are: • Severe low flows on specific tributaries • Reduced juvenile production caused by insufficient habitat. • Changes in flow regime resulting in the wash out of gravels and redds. • The impact of man made structures preventing access to suitable spawning areas, and preventing the downstream distribution of spawning gravels.