702 resultados para Devasher, Devon


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This is the River Dart Scale Reading Investigation Report on the 1971 season by the Devon River Board. The object of this investigation is to examine, by means of scale-reading, the general biology of the salmon population of the River Dart. In 1967 the final report on a five-year scale reading programme was summarised, at the time it was considered sufficient information to help with restocking programmes and the management of salmon population. But a further scale reading programme was started in an attempt to monitor changing patterns in salmon runs that may be caused by the new influences. It reviews the methods used for the collection of scales and examination of the materials. It shows the results of the survey and the number of scales studied from each of the various sea-age classes, time of running with distribution of the sea-age groups throughout the season, fish sizes and smolt ages at migration. All are summarized in tables, and figures are also included plotting weight distributions for each age classes and frequency distributions.

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This is the River Dart Scale Reading Investigation Report on the 1972 season by the Devon River Board. The object of this investigation is to examine, by means of scale-reading, the general biology of the salmon population of the River Dart. In 1967 the final report on a five-year scale reading programme was summarised, at the time it was considered sufficient information to help with restocking programmes and the management of salmon population. But a further scale reading programme was started in an attempt to monitor changing patterns in salmon runs that may be caused by the new influences. It reviews the methods used for collection of the scales and examination of the materials. It shows the results of the survey and the number of scales studied from each of the various sea-age classes, time of running with distribution of the sea-age groups throughout the season, fish sizes and smolt ages at migration. All is summarized in tables, and figures are included showing weight distributions for each age classes and frequency distributions.

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This is the Fisheries Survey River Avon, 1962 by the Devon River Board. The object of the survey is to investigate the present distribution and relative abundance of salmonid fish in the river. It describes the methods of the investigation, the sampling and identification. It goes through the salmon, sea-trout and brown trout parrs, adult and coarse fish frequencies and distributions, all summarized in individual tables for each fish class. It also includes a variety of comments about the obtained results.

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This is the River Teign Fisheries Survey from 1963 by the Devon River Authority. The principal object of the survey is to examine the distribution and relative abundance of salmonid fish in the river system in order to assess the possibility of increasing the salmon population by artificial propagation. A secondary object is to examine the condition of the river downstream of the Rookery Brook confluence, which was affected by the pollution and fish mortality in 1962 to assess the advisability of restocking the length with brown trout. The report contains a brief introduction of the general aspects of the catchment, chemistry, pollution, biology and fisheries in the river, methodology that looks at the selected transects and techniques for sampling and results. In the appendix, it is explained why the Board have decided to proceed with the artificial propagation and the required procedure. Maps with survey sections and fish indices along with tables with size distributions and totals of salmonids found are attached.

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This is the Second River Teign Fisheries Survey from July and August 1972 by the Devon River Authority. The aim of the survey was to assess the distribution and relative abundance of salmonid fish in the River Teign, describing the methods and results. The section on methods contains information of the selected transects and methodology for the survey. The results goes through totals of all salmonid fish caught, adults, parrs and estimations of parr population individually for salmo salar and salmo trutta. Maps with survey sections and fish indices along with tables with size distributions and totals of salmonids found are attached.

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This is the River Teign Fisheries Survey from August 1979 by the South West Water Authority. The River Teign was sampled by electrofishing at fifteen sites and population estimates, average lengths, weights and biomass were calculated for each species present, and where possible for individual age classes of those species. Results indicated that a stable community structure existed, and little had changed from 1963. Salmonids accounted for the majority of the biomass, and within this group trout were the most abundant in the headwater, and salmon in the lower reaches. All tributaries sampled had higher densities and biomass than the main river. The results were compared with other data collected from similar surveys of other rivers in Devon by the South West Water Authority. Both the average length of each age class, and the biomass in the main River Teign appeared to be lower than in most other rivers, although in the Rivers Wray and Lemon these values were particularly high.

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This is the River Teign Fisheries Survey from 1990 by the Environment Agency Archives South West (unpublished). The aim of the survey was to assess the distribution and relative abundance of salmonid fish in the River Teign. Thirty six sites were examined; twenty one of them had been examined in previous quantitative fish surveys. At each site, all fish species encountered were caught and measured, however, only data for salmonid fishes has been examined. The results are compared with those of the 1963 and 1972 surveys carried out by the Devon River Authority and the 1975 and 1979 surveys carried out by South West Water Authority. A full list of sites together with their location, fish densities, lengths, weights and ages is attached.

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This is the River Erme Fisheries Survey, 1965 by the Devon River Authority. The survey was carried out during April and May 1965, with the principal object being the determination of the abundance and distribution of salmonid fish in the River Erme in relation to the discharge from Stowford Paper Mills, Ivybridge. It contains a brief introduction of general aspects of the catchment, chemistry, pollution, biology and fisheries in the river, methodology that looks at the selected transects and techniques for sampling, results and recommendations. It contains tables with totals of all salmonid fish found at each section, size distribution of trout, surface area of section and population density.

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This is the River Exe Fisheries Survey 1966-1967 by the Devon River Authority. This is the fifth Fisheries Survey to be carried out in the initial series, other surveys having been carried out on the Rivers Teign, Torridge, Dart and Erme. The object of the survey was to examine the distribution and relative abundance of salmonid fish in the river system, in order to assess the possibility, or desirability, of increasing salmon smolt production of the river by artificial propagation or other means. The survey was carried out from middle May to end of July in 1966 when further survey work was prevented by high water levels, and from the end of June to the end of September in 1967. It contains a brief introduction of general aspects of the catchment, chemistry, pollution, biology and fisheries in the river, methodology that looks at the selected transects and techniques for sampling, results and recommendations. The results goes through totals of all salmonid fish caught, adults, parrs and estimations of parr population individually for salmo salar and salmo trutta. Maps with survey sections and fish indices along with tables with size distributions and totals of salmonids found are attached.

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This is the 5th Annual Report of the Rive Exe Scale Reading Investigation for the 1970 season by the Devon River Authority. The object of this investigation is to examine, by means of scale reading, the biology of age classes of the salmon population of the River Exe. It reviews the methods used for the collection of scales and examination of the materials. It shows the results of the survey and the number of scales studied from each of the various sea-age classes, time of running with distribution of the sea-age groups throughout the season, fish sizes and smolt ages at migration. All is summarized in tables, and figures are included showing weight distributions for each age classes and frequency distributions.

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This is the 6th Annual Report of the Rive Exe Scale Reading Investigation for the 1971 Season by the Devon River Authority. The object of this investigation is to examine, by means of scale reading, the biology of age classes of the salmon population of the River Exe. It reviews the methods used for the collection of scales and examination of the materials. It shows the results of the survey and the number of scales studied from each of the various sea-age classes, time of running with distribution of the sea-age groups throughout the season, fish sizes and smolt ages at migration. All is summarized in tables, and figures are included showing weight distributions for each age classes and frequency distributions.

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This is the 7th Annual Report of the Rive Exe Scale Reading Investigation for the 1972 Season by the Devon River Authority. The object of this investigation is to examine, by means of scale reading, the biology of age classes of the salmon population of the River Exe. It reviews the methods used for the collection of scales and examination of the materials. It shows the results of the survey and the number of scales studied from each of the various sea-age classes, time of running with distribution of the sea-age groups throughout the season, fish sizes and smolt ages at migration. All is summarized in tables, and figures are included showing weight distributions for each age classes and frequency distributions.

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This is the River Exe Salmon Action Plan Consultation document produced by the Environment Agency in 2003. The report pays attention on the external consultation of the River Exe Salmon Action Plan (SAP). This strategy represents an entirely new approach to salmon management within the UK and introduces the concept of river-specific salmon spawning targets as a salmon management tool. The River Exe SAP follows the format of those completed for the Rivers Teign, Torridge, Taw and Dart. It is the fifth of eight action plans that will be produced for salmon rivers within Devon Area. The River Exe SAP contains a description of the river catchment and highlights particular features that are relevant to the salmon population and the associated fishery. The Exe salmon stock is judged to be meeting its Conservation Limit. However, this assessment is uncertain as it is based on an estimate of rod exploitation rate, which in itself is also uncertain. At present there is no means of accurately assessing the River Exe salmon run. In common with many other rivers, estimation of stock using catch statistics and rod exploitation rate is the model used, when direct assessment is not possible. The installation of a fish counter on the lower river, or the use of other direct counting methods, would help to provide a direct assessment of the annual run of salmon into the river. This would improve our ability to estimate the spawning escapement and hence assess compliance with the Conservation Limit.

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This is the River Lyn Salmon Action Plan Consultation document produced by the Environment Agency in 2003. The report pays attention on the external consultation of the River Lyn Salmon Action Plan (SAP). This approach to salmon management within the England and Wales introduces the concept of river-specific Conservation Limits as a method of assessing the status of the salmon stock. The River Lyn Salmon Action Plan follows the format of those completed for the Rivers Exe, Axe, Avon & Erme, Teign, Torridge, Taw and Dart. It is the last of eight action plans that have been produced for salmon rivers within Devon Area. The River Lyn Salmon Action Plan contains a description of the river catchment and highlights particular features that are relevant to the salmon population and the associated fishery. The Lyn salmon stock is judged to be meeting its Conservation Limit. However, this assessment is uncertain as it is based on an estimate of rod exploitation rate, which in itself is also uncertain.

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This is the River Teign Salmon Action Plan Consultation document produced by the Environment Agency in 2003. The report pays attention on the external consultation of the River Teign Salmon Action Plan (SAP). This approach to salmon management within the England and Wales introduces the concept of river-specific Conservation Limits as a method of assessing the status of the salmon stock. The River Teign Salmon Action Plan follows the format of those completed for the Rivers Torridge, Taw and Dart. It is the fourth of eight action plans that will be produced for salmon rivers within the Devon Area Fisheries, Recreation and Biodiversity Team. The River Teign SAP contains a description of the river catchment and highlights particular features that are relevant to the salmon population and the associated fishery. The Teign salmon stock is currently failing to meet its conservation limit. This failure is largely attributed to the reduction in the survival rate during the marine phase of the salmon life cycle. This is likely to constrain stocks to lower levels than have existed historically. Still further catch controls may contribute to a reduction in exploitation rates and allow stocks to recover to meet their conservation limit. Other important actions include the continuation of habitat improvement works which aim to maximise spawning habitat utilisation, spawning success, and juvenile survival and production.