398 resultados para Salmon.


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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 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 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 Gunnislake Fish Counter, Annual Report 1999 produced by the Environment Agency South West Region on March 2000. The report presents the daily upstream counts of migratory salmonids recorded at Gunnislake Weir fish counting station (SX 435 713) situated on the River Tamar in 1999. The counter data contained within this report covers the period of the commercial migratory salmonid net buy-back scheme and the implementation of the National Spring Salmon Byelaws. The fish counter at Gunnislake is a resistivity based system (Logie 2100A – Aquantic limited) and is installed in the fish pass on the Cornish bank of the River Tamar at the head of the tide. The minimum salmon count for 1999 was 2691. The run pattern observed for salmon and sea trout in 1999 was generally consistent with that of previous years. However, the total combined annual count of salmon and sea trout migrating upstream on the River Tamar in 1999 was 25% higher than the 5 year average (1994 - 1998).

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This is the Restormel Fish Counter, Annual Report 1999 produced by the Environment Agency South West Region on March 2000. The report presents the daily upstream counts of migratory salmonids recorded at Restormel Weir counting station (SX 107 613) River Fowey in 1999. The counter data covers the period of the commercial migratory salmonid net buy-back scheme, which was in operation between March and June 1999. The fish counter is a resistivity based system (Logie 2100 A - Aquantic limited) and operates over all three channels of the weir at Restormel. The minimum salmon count estimate was 497, and the 1999 upstream count for sea trout was 6590. The run pattern observed for salmon and sea trout in 1999 was generally consistent with that of previous years. Flows on average were half those of 1998 during September, October, and November.

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This is the Gunnislake Fish Counter, Annual Report 2000 produced by the Environment Agency South West Region on March 2001. The report presents the daily upstream counts of migratory salmonids recorded on the River Tamar at Gunnislake Weir fish counting station (SX 435 713) situated in 2000. Data contained within this report covers the period of the commercial migratory salmonid net buy-back scheme and the National Spring Salmon Byelaws. The fish counter at Gunnislake is a resistivity based system (Logie 2100A – Aquantic limited) and is installed in the fish pass on the Cornish bank of the River Tamar at the head of the tide. The minimum salmon count for 2000 was 2654. The 2000 upstream count for sea trout was 6417. The run pattern observed for salmon and sea trout in 2000 was generally consistent with that of previous years.

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This is the Gunnislake Fish Counter, Annual Report 2001 produced by the Environment Agency South West Region on March 2002. The report presents the daily upstream counts of migratory salmonids recorded on the River Tamar at Gunnislake Weir fish counting station (SX 435 713) situated in 2001. Data contained within this report covers the period of the commercial migratory salmonid net buy-back scheme and the National Spring Salmon Byelaws. The fish counter at Gunnislake is a resistivity based system (Logie 2100A – Aquantic limited) and is installed in the fish pass on the Cornish bank of the River Tamar at the head of the tide. The minimum salmon count for 2001 was 3138. The 2001 upstream count for sea trout was 7503. The run pattern observed for salmon and sea trout in 2001 was generally consistent with that of previous years.

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This is the Restormel Fish Counter, Annual Report 2001 produced by the Environment Agency South West Region on March 2002. The report presents the daily upstream counts of migratory salmonids on the River Fowey at Restormel Weir fish counting station (SX 107 613) in 2001. The counter data covers the period of the commercial salmonid net buy back scheme and the national spring salmon byelaws. These reduce the commercial netting season for salmon and sea trout to between 16 June and 31 August. The fish counter at Restormel is installed on a crump sectioned weir on the River Fowey. The fish counter is a resistivity based system and operates over all three channels of the weir. 2001 was a good year for large sea trout. The number of returning large sea trout was above average in April, May, June and July and equal to or higher than the previous recorded maximum in those months. The main run of small sea trout occurred at a similar time to previous years with the highest numbers of fish entering the Fowey during June and July.

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This is the Gunnislake Fish Counter Annual Report 2002 from the Environment Agency South West Region, which was held on March 2002. It presents the daily upstream counts of migratory salmonids recorded on the River Tamar at Gunnislake Weir fish counting station in 2002. The data within this report covers the period of the commercial migratory salmonid net buy-back scheme and the National Spring Salmon Bylaws. The report contains section on Net Buy-Back; Species Apportionment; Validation of counter efficiency; results as total number of migratory salmonid (salmon and Sea Trout) counted moving upstream in 2002 at Gunnislake; video validation and Counter Efficiency; and Discussion. The section Discussion includes Salmon and Sea Trout counts recorded on the River Tamar 1995-2002, other fish species observed as sea lamprey and Environmental Factors (river flows, water temperature, and barometric pressure).