81 resultados para Upstream
Resumo:
This fisheries report summarises developments of the year 1993 in the North West region of the National Rivers Authority. It provides catch statistics, rod and line and commercial catches for salmon and sea trout, fish culture and hatchery operations, restocking with trout and freshwater fish, upstream fish movement recorded at authority fish counters, counts of salmon and sea trout spawning redds, fish mortalities, licences issued, and prosecutions. Among the streams that are covered in the report are the River Lune, River Kent, River Leven, River Ribble and River Derwent.
Resumo:
This report covers the upstream movement of 1,719 salmon in the River Leven during the year 1965. An analysis of river levels taken at hourly intervals from April to November 1965 correlated to fish movement at the exact river level when fish moved is provided. The report concludes that major quantities of water from the Rivers Lune and Leven can be made available for domestic and industrial supply without harming the fisheries.
Resumo:
Fish tracking is a valuable technique for the provision of detailed information on the behaviour patterns of individual fish especially during estuarine and riverine migration. 2. Tracking studies help in the provision of a comprehensive description of the variety offish behaviour patterns in response to factors such as water flow, obstructions and water quality. 3. There are advantages to be gained by complementing fish tracking studies with data collected from fish counters and vice versa. 4. An overall evaluation of NRA fish tracking projects is presented in the wider context of NRA strategic research objectives. 5. The requirement for future development of tracking equipment, improved data analysis techniques, better communication and more immediate report preparation is identified. 6. Individual project evaluation is given for NRA (or the appropriate Water Authority predecessor) tracking studies conducted on the Ribble estuary, the River Tamar, River Torridge, Rivers Test and Itchen, River Lodden, the Welsh River Dee, River Glaslyn, River Taff, River Tawe, River Tywi, River Usk, Rivers Avon and Stour and the River Frome. 7. An outline for future strategic research is provided which identifies particular areas for study:- i) Identification of environmental factors which control the entry of fish into rivers. ii) Improvement of the understanding of the relationship between water flow and upstream movement of salmonids. iii) Examination of the detailed movements and behaviour of fish in relation to obstructions. iv) Closer definition of water quality requirements for salmonid fish. v) Definition of habitat preferences of salmonids in rivers. vi) Subsidiary topics such as the movements of non-salmonid fish and the downstream migration of kelts and juvenile salmonids.
Resumo:
Following a large scale fish mortality caused by a considerable spillage of a pentachlbrophenol-based disinfectant from a mushroom farm, a biological survey of the river Conder was undertaken on 23.7.79. A spillage of this same make of disinfectant from this mushroom farm in February 1976 caused a similar large scale fish mortality. On that occasion, the pollution appeared to have little effect on the benthic invertebrates of the river Conder, with no dead organisms found, although the small beck which received the spillage was quite badly affected. This recent spillage of disinfectant involved a considerably greater volume (approximately 900 gallons) than the 1976 discharge and so this report looks at whether invertebrate fauna of the main river were affected on this occasion. Kick samples were taken at a number of sites in the river Conder from the confluence with the polluted beck to Conder Green. A control sample was also taken upstream of the confluence with the polluted beck. All samples were examined on site and live and dead invertebrates noted and identified as accurately as possible.
Resumo:
This report summarises the findings of a series of electric-fishing surveys carried out at four sites on the River Ribble from September 1997 to September 1998. The aims of these surveys were to assess the impact on juvenile salmonids of a pollution incident involving Synthetic Pyrethrin (SP) that occurred near High Birkwith I (SD 802 767) in September 1997.One of these sites was 2.65km upstream of the pollution whilst the remaining three were at varying distances downstream. Data was collected during surveys of the River Ribble in 1992, 97 and 98. The 1997 and 1998 surveys were carried out specifically to monitor for any possible effects of the SP discharge. Data are shown as grades derived from the National Fisheries Classification scheme (NFC). Results are given for the four salmonid life stages; 0+ trout, >0+ trout, 0+ salmon, >0+ salmon and also Total Salmonids.
Resumo:
The present report was prepared for the Water and Food Challenge Program project “Optimizing the management of a cascade of reservoirs at the catchment level” (MK3). It constitutes the baseline assessment of fish and fisheries in the Sesan River Basin. The objective of the MK3 project is to contribute knowledge and recommendations so that cascades of reservoirs corresponding to hydropower dams in the Mekong Basin are managed in ways that are more fair and equitable for all water users. This project seeks to understand at the catchment scale the cumulative upstream and downstream consequences of management decisions taken for multiple reservoirs. Revised rules for water storage infrastructure management will in particular take into account fisheries and agricultural potential as well as hydropower gen
Resumo:
We used 25 years of conventional tagging data (n= 6173 recoveries) and 3 years of ultrasonic telemetry data (n=105 transmitters deployed) to examine movement rates and directional preferences of four age classes of red drum (Sciaenops ocellatus) in estuarine and coastal waters of North Carolina. Movement rates of conventionally tagged red drum were dependent on the age, region, and season of tagging. Age-1 and age-2 red drum tagged along the coast generally moved along the coast, whereas fish tagged in oligohaline waters far from the coast were primarily recovered in coastal regions in fall months. Adult (age-4+) red drum moved from overwintering grounds on the continental shelf through inlets into Pamlico Sound in spring and summer months and departed in fall. Few tagged red drum were recovered in adjacent states (0.6% of all recoveries); however, some adult red drum migrated seasonally from overwintering grounds in coastal North Carolina northward to Virginia in spring, returning in fall. Age-2 transmitter-tracked red drum displayed seasonal emigration from a small tributary, but upstream and downstream movements within the tributary were correlated with fluctuating salinity regimes and not season. Large-scale conventional tagging and ultrasonic telemetry programs can provide valuable insights into the complex movement patterns of estuarine fish.
Resumo:
This is the River Dart, Weir and Fish Pass Survey 1992 report produced by the National Rivers Authority. It goes through the general condition of Weirs and fish passes to determine the extent of problems associated with the upstream and downstream migration of salmonids. It considers solutions where problems exist and investigates the exact use of the resource. It looks at the following Weirs: Totnes, Staverton, Hood, Kilbury, Buckfast, Holne, Mardle (River Mardle), Holybrook (Holybrook), Jordan (West Webburn), Swincombe Intake (River Swincombe), Blackbrook, West Dart, Cowsic (Devonport Leat), Kingfisher Press (Bidwell Brook) and Bagpark (East Webburn). It also contains location maps of the weirs and individual fact sheets along detailed pictures and diagrams.
Resumo:
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).
Resumo:
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.
Resumo:
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.
Resumo:
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.
Resumo:
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.
Resumo:
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).
Resumo:
This is the Restormel Fish Counter, Annual Report 2002 produced by the Environment Agency South West Region on March 2003. The report presents the daily upstream counts of migratory salmonids recorded on the River Fowey at Restormel Weir fish counting station (SX 107 613) in 2002. Data contained within this report covers the period of the commercial migratory salmonid net buy-back scheme and the National Spring Salmon Bylaws. The fish counter at Restormel is a resistivity based system (Logie 2100A - Aquantic limited) and is installed on the weir at Restormel approximately 2 km upstream of the tidal limit. The run pattern observed for salmon and sea trout in 2002 was generally consistent with that of previous years. The upstream salmon / large sea trout count for 2002 was 1804.