944 resultados para CATCHMENT-AREA


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The stock of salmon in any river is largely dependent upon the escapement of sufficient fish to ensure that an adequate quantity of ova is deposited and full use is made of all suitable spawning areas. At the present time, no accurate information is available on the numbers of fish entering rivers. Therefore, catch returns provide valuable information on fish stocks. This report summarises the catch returns for salmon in the Lancashire River Authority in the North of England for the years 1960-1964. Rivers included are the Lune, Ribble, Kent, Leven and Duddon.

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As part of the River Lune juvenile salmonid investigation, a number of sites on the River Wenning catchment were electrofished annually from 1981 - 1985. Particularly low Salmon parr populations were evident for much of the Wenning catchment which has caused some concern. All the Wenning catchment electrofishing results are reported in this paper and comparisons are made with designated groups of sites on the remainder of the Lune catchment. These groups of sites are: River Lune and tributaries, upstream Tebay, Upper Middle Lune, Lower Middle Lune, Lower Lune, Birk & Borrow Becks, Chapel & Crosdale Becks, Rawthey system, Barbon & Leek Becks and the Greta system. The general scarcity of Salmonids in large sections of the main river Wenning probably reflects the apparent limited natural spawning areas on the catchment. Details of Salmon fry and ova planting on the Wenning catchment since 1981 have been collated and whilst survival through the 0+ stage appears to be quite good, recruitment to the 1++ stage appears to be poor. Water quality does not appear to be responsible for the very low salmonid densities at some main river sites but is possibly a factor in apparently preventing any Salmon run in Keasden Beck. Recommendations for future Fisheries and Biological work are given.

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The aim of this study was to assess the status of the juvenile salmonid populations of the River Lune and its tributaries. There was special emphasis on juvenile salmon stocks in view of the implementation of a net limitation order in 1980. The number of licensed instruments were reduced as follows: (1) Drift, hang or whammel nets - from 12 to 10 (2) Draft or seine nets - from 3 to 1 (3) Heave or haaf nets - from 4 6 to 2 6 For the purpose of this report, the River Lune system has been divided into 13 subcatchments and these are examined with a view to detecting any trends in the data such as subcatchment productivity, partitioning between salmon and trout nursery streams, and whether the restrictions on salmon fishing had any discernible effects on juvenile salmon productivity. The effect of flow and instream obstructions on salmonid densities are also investigated as these have been shown to be important factors affecting abundance. Throughout the study period a programme of enhancement stocking took place primarily with salmon ova and fry. The possible impact of this on the results of the surveys has been assessed. The distribution and abundance of juvenile salmon was found to be relatively consistent in each of the 13 subcatchments studied over the 1981-1985 period.

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This report summarises the fisheries electrofishing survey work undertaken on the River Lune, England, in the period 1981-85 and 1991. As part of a long term monitoring programme by the National Rivers Authority, juvenile surveys, with the emphasis on salmonids, have been carried out on the River Lune on a number of occasions since 1981. The latest survey in 1991 now gives the opportunity to assess what, if any, changes have occurred in the juvenile populations across the last 11 years and how future fisheries management may impact on the River Lune as a fishery. The areas of trout and salmon, fry and parr production will be considered in detail, as will adult trout populations. Water quality issues will be mentioned briefly as will habitat issues, where they are deemed to be important in affecting fish densities.

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[ES]Este proyecto recoge el plan de internacionalización comercial a Brasil, Marruecos y Francia de la empresa de ámbito industrial; concretamente del sector de la siderurgia, en adelante, A.P.S., que se dedica a la elaboración de productos auxiliares para la desulfuración del acero. El plan se ha desarrollado de forma que impulse a la empresa a cumplir una serie de objetivos como son un mayor crecimiento, mejora de la rentabilidad o un aumento de cuota de mercado, entre otros. Las pautas seguidas en la elaboración del plan de acciones, han sido desarrolladas gracias a un adecuado análisis tanto para la empresa como para el entorno, que ha sido de especial ayuda para ajustarnos a las necesidades de esta.

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An extensive survey of the River Lune using River Habitat Survey (RHS) was commissioned to assess the habitat quality of the Lune for salmonid fish. The main river on the Lune and tributaries were divided into 500m sections. A sample of 103 sections (25% of the total classified length) was randomly selected and surveyed in February/March 99. A Habitat Modification Score (HMS) describing the level of habitat modification was derived for each site and compared to the whole reference network and to rivers of similar types in Britain. The analysis of Habitat Modification scores show that more than 70% of the sites on the catchment are predominantly unmodified and very few sites are significantly modified (less than 10% of the sites). The analyses of the data collected suggest that although river habitats are altogether of good quality, the natural processes within the catchment may reduce spawning habitats for salmonids. The river processes appear to be driven by natural forces, although land-use is likely to impact on the levels of run-off. Further analyses using fisheries data on the Lune will investigate the relationship between the major environmental dimensions and fish distribution on the catchment.

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The Ribble catchment is the largest and most diverse river system within National Rivers Authority (NRA), North West's Central Area. The river is approximately 100km in length and rises in a limestone area west of the Pennines. This report examines changes in the size and composition of the salmon and sea trout catches from the Ribble migratory salmonid fisheries during the years 1937 to 1991. Comparisons are made between the rod and net fisheries for both salmon and sea trout of the Ribble and Hodder. Patterns of catches shown by the Ribble fisheries are compared with those of other individual rivers and with patterns for the North West Region as a whole. An attempt is made to identify if any relationship exists between catch and stock abundance. Catch patterns shown by the Ribble and Hodder salmon fisheries are compared with electronic resistivity counter data from the two rivers. Annual salmon catch patterns and redd count data are compared both locally and regionally. Recommendations for future studies are made in the light of the report's findings.

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The River Douglas has a long industrial heritage beginning in the early 18th century with its use by boats carrying goods between Wigan and Tarleton. The River and its tributaries have also historically been, and to a certain extent are still, subject to polluting inputs from the urban, agricultural and industrialised areas located within its catchment. During the early stages in the production of the River Douglas Catchment Management Plan, it became apparent that very little data existed on the populations of coarse and salmonid fish species within the River Douglas system. The data that did exist was largely anecdotal, consisting of catch reports from anglers or water bailiffs, or of dead and distressed fish following pollution incidents. This study was initiated to assess the status of coarse and salmonid fish species within the River Douglas system and so address the lack of knowledge. Eighty two sites were surveyed by electric fishing, including 14 sites using an electric fishing punt and up to four anodes. The data was analysed according to a new National Fisheries Classification Scheme. This classified the sites by the fish stock s present and compared the results with a database containing information from sites around the country that have similar habitat types. A stocking experiment was also undertaken in the River Lostock using chub reared at the Leyland Hatchery. These were marked with an identifiable blue spot in the spring of 1995 and then released into three, previously surveyed, locations in the river. These sites were then resurveyed during the summer stock assessment. This report also Site Reports with details on monitored sites, habitat features and fishery classification.

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There has been a perception of increasing river channel instability in north west rivers and the River Lune in particular in recent decades. This has been attributed variously to: (a) long-term trends in precipitation-runoff regime; (b) changes in land-use such as moor-draining and sub-soil draining such that the river is more flashy than previously, and (c) a change in the magnitude-frequency relationships of flow such that high discharges are occurring with increased frequency. Resources are available in the form of rainfall and runoff records, archived information on channel planform, land use statistics and local engineering experience which have not been jointly and fully evaluated. Effective interpretation of the nature of channel change through time with respect to this resource may enhance the Environment Agency's ability to manage the river channel efficiently in the future and will aid the development of effective policy. The results of this study will for the first time, provide robust guidance with respect to long-term channel adjustment and the appropriate management options. The research provides suggestions as to how policy might be developed taking account of other pertinent factors.

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A presente pesquisa tem como objetivo geral analisar as representações sociais da hierarquia construídas pelos militares da FAB, considerando suas segmentações em termos dos círculos de oficiais e graduados, dos respectivos processos de formação, dos sexos de seus componentes e dos estágios, se formados ou em formação, em que se encontram. A fundamentação teórica discorre sobre a hierarquia, princípio geral das instituições militares, previsto por lei e regulador do comportamento militar, conforme prevê o Estatuto dos Militares (BRASIL, 1980); a respeito do poder, na perspectiva de Max Weber (1999) que trata a obediência, a partir da autoridade de uma pessoa sobre outras, e de acordo com Amitai Etzioni (1974), que entende o poder como a capacidade que uma pessoa tem de induzir outra a seguir suas orientações. Apresenta ainda a Teoria das Representações Sociais, proposta por Serge Moscovici (1961), para quem as representações sociais servem de instrumento de leitura da realidade, e a partir da abordagem estrutural, proposta por Jean-Claude Abric (1976), segundo a qual a representação social é composta pelo sistema central, constituído pelo núcleo central, e pelo sistema periférico, formado por elementos periféricos. A amostra foi composta por 600 militares, oriundos das escolas de formação de oficiais e de graduados, do âmbito do Comando da Aeronáutica (COMAER): Academia da Força Aérea (AFA), cuja finalidade é a formação dos Oficiais da Ativa dos quadros de Aviação, de Intendência e de Infantaria, a Escola de Especialistas da Aeronáutica (EEAR), responsável pela formação e pelo aperfeiçoamento dos graduados e o Centro de Instrução Especializada da Aeronáutica (CIEAR), responsável pela capacitação de oficiais e graduados em áreas afins à sua especialização. A coleta de dados foi realizada por meio da técnica de evocação livre ao termo indutor hierarquia, da aplicação do questionário de caracterização e do questionário geral, composto por questões abertas e fechadas. As evocações foram processadas pelo software EVOC, desenvolvido por Pierre Vergès (2005), as questões fechadas receberam o processamento com o auxílio do software SPSS e as questões abertas sofreram uma categorização para o refinamento das análises. Os resultados encontrados nas comparações do conteúdo temático e da estrutura das representações sociais entre os diferentes segmentos permitem afirmar que os temas respeito e disciplina são os prováveis elementos centrais da hierarquia para o conjunto dos 600 militares pesquisados e caracterizam a base comum e consensual compartilhada na caserna. A hierarquia, norteada por um conjunto de regras que regula e assegura a disciplina e o respeito, direciona o comportamento dos militares, durante a formação e no decorrer da carreira. Da análise, conclui-se que os diferentes segmentos de militares da FAB possuem a mesma representação social de hierarquia.

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The aim of this study was to investigate the historical catch record from the Castle Fishery on the River Derwent over the period 1923 - 1989, to determine if changes had taken place in the composition of the catch and to examine the influence of flow on the performance of the fishery. The River Derwent is situated in West Cumbria, North West England. It flows from its source on Scafell Pike (NGR NY 229 089) westwards discharging into the Irish sea at Workington, a distance of 52 km. Over its length it receives water from an additional 214 km of stream, 5 large lakes and approximately 30 small tarns. The catchment drains a total area of 663 km2. The study concludes that through the time period there was considerable variation in catch between years. The trend was for the catch to increase steadily over the period 1923 - 1958, declining rapidly in 1959, after which catches increased steadily reaching a peak in the mid-sixties, before declining towards the end of the decade. During the seventies and eighties catches remained relatively stable at between 300 - 600 salmon per year until 1988 when over 2000 salmon were reported caught, the greatest number in any year over the study period.

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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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All species of fish are able to propagate and maintain their numbers provided that no adverse influence occurs to change the compatible environment, the salmon is no exception. Propagation of fish by artificial means has long been a subject of discussion amongst fishery workers and views have been expressed (both favourable and unfavourable) on the merits of the various methods employed. In an attempt to discover whether artificial propagation was necessary and also to find the best methods of propagation to adopt in the various rivers, a phased programme of investigation into natural spawning efficiency and the results obtained by various methods of artificial propagation was started in the Lancashire River Board area during 1957. The object being to seek information on: (1) The survival of ova from natural spawnings to the eyed and alevin stages. (2) The population density of feeding fry (from natural spawnings) at various intervals of development. (3) The viability of green ova and eyed ova- when planted artificially. (4a) The survival to 0+ parr from implants of eyed ova unfed fry and fed fry. (4b) Populations per unit area of 0+ parr from various planting densities of eyed ova, unfed fry and fed fry. Sampling stations were selected on the Rivers Ribble, Lune and Wyre watersheds for the purpose of marking and examination of natural salmon redds.

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This report explores salmon propagation in the Lancashire River Board area (North West of England), looking at the Rivers Lune, Wyre, Ribble, and Hodder, showing salmon catch statistics, methods of propagation and habitat conditions investigations.