951 resultados para Liverpool, England


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This dataset provides raw data of chemical analyses made during studies on seasonal variations of treated sewage effluent from Grasmere Treatment Unit in Cumbria. Measurements of sodium, calcium, potassium, magnesium and chloride ions were taken between 1974 and 1976.

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Over a number of years complaints have been made by various angling associations within the area of the Lancashire and Mersey and Weaver River Authorities about the unsatisfactory state of the fisheries in the Leeds/Liverpool Canal. Following upon discussions with the associations the Lancashire River Authority agreed to carry out an investigation into the fish species and their populations. The survey has extended over two years and it is hoped that the following information will be of value to all concerned. The canal is 127 miles in length when measured from the River Aire at Leeds to the docks at Liverpool. The survey was confined to two sections: i) That part of the canal which passes through the area of the Lancashire River Authority; and ii) 10 miles of that section which runs through the area of the Mersey and Weaver River Authority. The fish were sampled by electro-fishing, a 100 yard section of canal being sampled at each one mile interval. Water samples for chemical analysis were taken immediately prior to the commencement of fishing operations. The analyses were intended to demonstrate the quality of the water in which the fish were living at the time of the survey. Regular samples of the fauna and flora present in the canal were taken and examined in the fisheries laboratory of the Authority.

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Eight streams from the North West of England were stocked with Atlantic salmon (Salmo salar L.) fed fry at densities ranging from 1 to 4/m2 over a period of up to three years to evaluate survival to the end of the first an d second growing periods and hence assess the value of stocking as a management practice. Survival to the end of the first growin g period (mean duration of 108 days) was found to vary between 7.8 and 41.3% with a mean of 22% and CV of 0.44. Survival from the end of the first growing period to the end of the second growing period (mean duration of 384 days) ranged from 19.9 to 34.1% with a mean of 26.3% and CV of 0.21. Survival was found to be positively related to 0+ trout density (P < 0.05) and negatively related to altitude (P < 0.05). A comparison of the raw survival data (non standardised with respect to duration of experiments) with that from other studies in relation to stocking densities revealed a negative relationship between fry survival and stocking density (P < 0.05). Densities in excess of 5/m2 tended to result in lower levels of survival. Post stocking fry dispersal patterns were examined for the 1991 data. On average 86.7% of the number of fry surviving remained within the stocked zone by the end of the first growing period. With the exception of one stream there was little in the way of dispersal beyond the stocked zone. The dispersal pattern approximated to the normal distribution (P < 0.05). It was estimated that stocking can result in a net gain of fish to a river system compared with natural productivity, however the numerical significance of this gain and its cost effectiveness need to be determined on a river specific basis.

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This paper deals with the development and use of biological reference points for salmon conservation on the River Lune, England. The Lune supports recreational and net fisheries with annual catches in the region of 1,000 and 1356 salmon respectively. Using models transported from other river systems, biological reference points exclusive to the Lune were developed; specifically the number of eggs deposited and carrying capacity estimates for age 0+ and 1+ parr. The conservation limit was estimated at 11.9 million eggs and between 1989 and 1998 was exceeded in two years. Comparison of juvenile salmon densities in 1991 and 1997 with estimates of carrying capacity indicated that 0+ and 1+ parr densities were at around 60 % of carrying capacity and may relate to the number of eggs deposited in 1990 and 1996 being approximately 70% of the target value. The paper discusses the management actions taken in order to ensure that the management target of the conservation limit being met four years out of five is delivered. It also discusses the balance between conservation and exploitation and the socio-economic decisions made in order to ensure parity of impacts on the rod and net fisheries. The regulations have been enforced since 1999 and the paper concludes with an assessment of the actions taken to deliver the management targets, over the last five years.

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This report looks at the interests of the Fisheries Department for the Lancashire River Board, focusing on the Liverpool and Leeds Canal Survey. It looks at finding parasites in fish from an electrofishing survey (roach and perch). This was to contribute towards the main survey with a possible view to suggesting whether or not the parasites were one reason for the poor fish population. Methods of finding parasites are given, and results of what parasites that were found in the fish are discussed.

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Although the Atlantic white-sided dolphin (Lagenorhynchus acutus) is one of the most common dolphins off New England, little has been documented about its diet in the western North Atlantic Ocean. Current federal protection of marine mammals limits the supply of animals for investigation to those incidentally caught in the nets of commercial fishermen with observers aboard. Stomachs of 62 L. acutus were examined; of these 62 individuals, 28 of them were caught by net and 34 were animals stranded on Cape Cod. Most of the net-caught L. acutus were from the deeper waters of the Gulf of Maine. A single stomach was from the continental slope south of Georges Bank. At least twenty-six fish species and three cephalopod species were eaten. The predominant prey were silver hake (Merluccius bilinearis), spoonarm octopus (Bathypolypus bairdii), and haddock (Melanogrammus aeglefinus). The stomach from a net-caught L. acutus on the continental slope contained 7750 otoliths of the Madeira lanternfish (Ceratoscopelus maderensis). Sand lances (Ammodytes spp.) were the most abundant (541 otoliths) species in the stomachs of stranded L. acutus. Seasonal variation in diet was indicated; pelagic Atlantic herring (Clupea harengus) was the most important prey in summer, but was rare in winter. The average length of fish prey was approximately 200 mm, and the average mantle length of cephalopod prey was approximately 50 mm.

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Long-term trends in the abundance and distribution of several pinniped species and commercially important fisheries of New England and the contiguous U.S. west coast are reviewed, and their actual and potential interactions discussed. Emphasis is on biological interactions or competition. The pinnipeds include the western North Atlantic stock of harbor seals, Phoca vitulina concolor; western North Atlantic gray seals, Halochoerus grypus; the U.S. stock of California sea lions, Zalophus californianus californianus; the eastern stock of Steller sea lions, Eumetopias jubatus; and Pacific harbor seals, Phoca vitulina richardii. Fisheries included are those for Atlantic cod, Gadus morhua; silver hake, Merluccius bilinearis; Atlantic herring, Clupea harengus; the coastal stock of Pacific whiting, Merluccius productus; market squid, Loligo opalescens; northern anchovy, Engraulis mordax; Pacific her-ring, Clupea pallasi; and Pacific sardine, Sardinops sagax. Most of these pinniped populations have grown exponentially since passage of the U.S. Marine Mammal Protection Act in 1972. They exploit a broad prey assemblage that includes several commercially valuable species. Direct competition with fisheries is therefore possible, as is competition for the prey of commercially valuable fish. The expanding pinniped populations, fluctuations in commercial fish biomass, and level of exploitation by the fisheries may affect this potential for competition. Concerns over pinnipeds impacting fisheries (especially those with localized spawning stocks or at low biomass levels) are more prevalent than concerns over fisheries’ impacts on pinnipeds. This review provides a framework to further evaluate potential biological interactions between these pinniped populations and the commercial fisheries with which they occur.

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This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 18th October, 1978. It covers information on fisheries income and expenditure, the study of salmon propagation in England and Wales, work on the future programme of fisheries work and keep nets. Other sections include the report on the effects of Barnoldswick STW on Stock Beck and the River Ribble, information on the Leeds/Liverpool Canal transfer of mine water from Bickershaw Colliery and the future fishing policy of Worthington Reservoir. It also covers the report by the area fisheries officer on fishing activities including river conditions and fishing for salmon, sea trout, and coarse fish, and an update on Langcliffe hatchery. The report also looks at migratory fish movements at Waddow Weir, Winckley Hall and Locks Weir, stocking numbers of brown trout, rainbow trout and coarse fish in various rivers, pollution incidents and fish mortalities. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

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This is the Salmonid & Freshwater Fisheries Statistics for England & Wales 1989 produced by the National Rivers Authority (NRA) in 1989. This report is focused on the maintenance, improvement and development of fisheries of England and Wales. This report is the first on salmon and migratory trout catch statistics for England and Wales published by the National Rivers Authority (NRA). From 1989 onwards, these statistics will appear each year as NRA fisheries statistics reports replacing the Data Report Series which was published by the Ministry of Agriculture Fisheries and Food (MAFF) Directorate of Fisheries Research. This report makes a general review of different catches: Northumbria, Yorkshire, Anglian, Thames, Southern, Wessex, South West, Severn-Trent, Welsh and North West.

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This is the Salmonid & Freshwater Fisheries Statistics for England & Wales 1990 produced by the National Rivers Authority (NRA) in 1992. This report is focused on the maintenance, improvement and development of fisheries of England and Wales. This report is the second compilation of salmon and migratory trout catch statistics for England and Wales published by the National Rivers Authority (NRA). Before 1989, these statistics were published by the Ministry of Agriculture Fisheries and Food (MAFF) Directorate of Fisheries Research in their Data Report Series. The 1990 data have been presented in a broadly similar format to those of 1989. However, two further NRA regions, four in all, provided effort data for rod fisheries in 1990. This report makes a general review of different catches: Northumbria, Yorkshire, Anglian, Thames, Southern, Wessex, South West, Severn-Trent, Welsh and North West.

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This is the Salmonid & Freshwater Fisheries Statistics for England & Wales 1992 produced by the National Rivers Authority (NRA) in 1994. This report is focused on the maintenance, improvement and development of fisheries of England and Wales. This report is the fourth compilation of salmon and migratory trout catch statistics for England and Wales published by the National Rivers Authority. For the years 1983-88, these statistics were published by the Ministry of Agriculture, Fisheries and Food (MAFF), Directorate of Fisheries Research in their Data Report Series. Other than for rod catches, the 1992 data have been presented in a broadly similar format to those of 1991, Presentation of the rod data however has changed considerably due to the introduction in January 1992 of the first National Rod Fishing Licence. This report makes a general review of different catches: Northumbria, Yorkshire, Anglian, Thames, Southern, Wessex, South West, Severn-Trent, Welsh and North West.

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This is the Salmonid & Freshwater Fisheries Statistics for England & Wales 1994 produced by the National Rivers Authority (NRA) in 1995. This report is focused on the maintenance, improvement and development of fisheries of England and Wales. This report is the sixth compilation of salmon and migratory trout catch statistics for England and Wales produced by the National Rivers Authority. For the years 1983-88, these statistics were published by the Ministry o f Agriculture, Fisheries and Food (MAFF), Directorate of Fisheries Research in their Data Report Series. The 1994 data have been presented in a broadly similar format to those of 1993.This report makes a general review of different catches: Northumbria, Yorkshire, Anglian, Thames, Southern, Wessex, South West, Severn-Trent, Welsh and North West.

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This is the Salmonid & Freshwater Fisheries Statistics for England & Wales 1996 produced by the Environment Agency in 1997. The principal aim of the Environment Agency in respect of fisheries is to maintain improve and develop fish stocks, the basic fisheries resource, in order to optimise the social and economic benefits from their sustainable exploitation. This report is the second collation of salmon and migratory trout catch statistics for England and Wales produced by the Environment Agency. For the years 1989-94, these statistics were published by the National Rivers Authority (NRA) and the years 1983-88 by the Ministry of Agriculture, Fisheries and Food, Directorate of Fisheries Research in its Data Report series. The 1996 data, have been presented in a broadly similar format to those of 1995. This report makes a general review of different catches: Northumbria, Yorkshire, Anglian, Thames, Southern, Wessex, South West, Severn-Trent, Welsh and North West.