947 resultados para North-West


Relevância:

70.00% 70.00%

Publicador:

Resumo:

This is the report from the West Cumbria Special Fisheries Advisory Group meeting, which was held on the 25th June, 1982. The report contains sections on the Application by British Nuclear Fuels Limited (BNFL) for a temporary licence to abstract additional quantities from Wastwater, and River Derwent Abstraction (Prescribed Flows). 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.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

This is the report from the West Cumbria Special Fisheries Advisory Group meeting, which was held on the 28th July, 1982. The report contains sections on minutes of the meeting held on the 25th June, 1982, Application by British Nuclear Fuels Limited (BNFL) for a temporary licence to abstract additional quantities from Wastwater, and River Derwent Abstraction (Prescribed Flows) and fisheries implications. 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.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

This is the report from the West Cumbria Special Fisheries Advisory Group meeting, which was held on the 9th March, 1983. The report contains sections on Fish Passes at Yearl Weir River Derwent, Ennerdale, and Ehen; River Calder abstraction and augmentation from boreholes; and the augmentation of River Ehen by minewater to support increased abstraction by BNFL. 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.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

This is the report from the West Cumbria Special Fisheries Advisory Group meeting, which was held on the 16th May, 1986. The report contains sections on a Fish Pass at Ennerdale, Authority proposals for discharge of compensation water from Ennerdale and a diagram of fish pass at Ennerdale. 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.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

This is the Water Resources in West Cumbria November 1976 report produced by the North West Water Authority. The report focuses on the provision of additional supplies of water in West Cumbria. In certain areas of West Cumbria difficulties arose in meeting peak demands. Moreover British Nuclear Fuels Ltd. (B.N.F.L) required additional water supplies. The area under consideration forms the western edge of the Lake District National Park and all the sources considered in this report, apart from the aquifer in the immediate vicinity of Calder Hall, lie wholly or partly within the National Park boundaries. The Rivers Ehen, Calder and Irt support migratory trout and salmon and are angling streams of a high quality. Amenity considerations therefore play an important part in determining the location and extent of any development.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

This is the report on the strategic fisheries stock assessment survey of the minor catchments in South West Cumbria 1996 with particular reference to salmonids, produced by North West Water in 1994. The 1996 Minor Catchment survey indicates variations in salmonid production within these catchments. Survey results indicate that production may be reaching its limit in certain areas whilst others are underachieving and others are unsuitable for salmonid production. Trout production within the catchments is higher and more widespread than that of salmon. Water quality levels vary considerably between catchments and intra-annually within individual catchments. The need for selective habitat surveys, with a view to habitat improvement schemes (H.I.S) is discussed. This report formed a basis for subsequent reports, thus, allowing data comparisons and analysis of production level fluctuations. It was the most extensive assessment of these catchments to date, taking into account comparisons with the new National Database on salmonid production in England and Wales.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Spawning temperature preferences for sardine (Sardina pilchardus) in the eastern North Atlantic were determined from field data. These were compared with climatological temperature cycles (1986-2002) derived from satellite data by geographical region, to predict spawning seasons. Optimum spawning temperatures were determined as 14.0-15.0oC from the English Channel to Portugal and 16.0–18.0oC for all north-west African regions. Spawning seasons were closely related to the general latitudinal trend of the annual temperature cycle, with modification by upwelling in the western Iberian and north-west African regions. Some differences between temperature-based spawning season predictions and field observations were related to variations in seasonal plankton production. Correlations in the annual time-series of favourable spawning temperatures suggested relatively strong linkages between the southern areas from Portugal to Senegal. There was no consistent relationship between annual variations in duration of temperature-predicted spawning seasons and observed field abundance of eggs.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Pipefish (Syngnathidae) have occurred with unprecedented frequency in Continuous Plankton Recorder (CPR) samples to the west of the British Isles from 2003 to 2005. Identification by mtDNA sequencing established that they were snake pipefish, Entelurus aequoreus. The geographical range of the records were from the outer continental shelf of the Celtic Sea and north-west of Ireland to the mid-Atlantic Ridge between 40° and 57°N, with the greatest abundance near the shelf edge and adjacent oceanic waters south of Ireland and west of Brittany. There were records in every month from February to November but most were in late spring and summer. A proposed mechanism for the increase in abundance of the species is that recent climate change has had beneficial impacts on the reproduction of adults and the survival of larvae and juveniles.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Pronounced changes in fauna, extending from the English Channel in the south to the Barents Sea in the north-east and off Greenland in the north-west, have occurred in the late 1920s, the late 1960s and again in the late 1990s. We attribute these events to exchanges of subarctic and subtropical water masses in the north-eastern North Atlantic Ocean, associated with changes in the strength and extent of the subpolar gyre. These exchanges lead to variations in the influence exerted by the subarctic or Lusitanian biomes on the intermediate faunistic zone in the north-eastern Atlantic. This strong and persistent bottom-up bio-physical link is demonstrated using a numerical ocean general circulation model and data on four trophically connected levels in the food chain – phytoplankton, zooplankton, blue whiting, and pilot whales. The plankton data give a unique basin-scale depiction of these changes, and a long pilot whale record from the Faroe Islands offers an exceptional temporal perspective over three centuries. Recent advances in simulating the dynamics of the subpolar gyre suggests a potential for predicting the distribution of the main faunistic zones in the north-eastern Atlantic a few years into the future, which might facilitate a more rational management of the commercially important fisheries in this region.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

This paper presents significant new insights into the appearance of agriculture at the north- western edge of Europe, focusing on Neolithic Ireland (4000-2500 cal BC). Previous studies were based upon a limited plant macro-remains dataset, as much of the Irish evidence is unpublished. A research project, 'Cultivating Societies', was implemented to examine the nature, timing and extent of agricultural activity in Neolithic Ireland through collation and analysis of different strands of published and unpublished archaeological and environmental evidence, with a particular focus on plant macro- remains, pollen, settlement and 14C data. Plant macro-remains from a total of 52 excavated sites were collated and analysed, representing the most comprehensive study to date of Neolithic plant remains from this region. Cereals were present at many locations and site types, sometimes in large quantities and most often at sites dating to the earlier Neolithic (3750-3600 cal BC). Emmer wheat was the dominant crop, at least at this time. Other crops included naked and hulled barley, naked wheat, einkorn wheat and flax. Analysis of arable weeds indicates that early plots were not managed under a shifting cultivation regime, which has important implications for understanding Neolithic settlement practices and how communities engaged with landscapes. The variety of crops cultivated in Neolithic Ireland is similar to those in Britain, reflecting a decreasing diversity in crop types as agriculture spread from south-east to north-west Europe.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

The geographic ranges of European plants and animals underwent periods of contraction and re-colonisation during the climatic oscillations of the Pleistocene. The southern Mediterranean peninsulas (Iberian, Italian and Balkan) have been considered the most likely refugia for temperate/warm adapted species. Recent studies however have revealed the existence of extra-Mediterranean refugia, including the existence of cryptic north-west European refugia during the Last Glacial Maxima (24-14.6 kyr BP). In this study we elucidated the phylogeographic history of two sibling bat species, Pipistrellus pipistrellus and P. pygmaeus in their western European range. We sequenced the highly variable mtDNA D-loop for 167 samples of P. pipistrellus (n = 99) and P. pygmaeus (n = 68) and combined our data with published sequences from 331 individuals. Using phylogenetic methodologies we assessed their biogeographic history. Our data support a single eastern European origin for populations of P. pygmaeus s.str., yet multiple splits and origins for populations of P. pipistrellus s.str., including evidence for refugia within refugia and potential cryptic refugia in north western Europe and in the Caucasus. This complex pattern in the distribution of mtDNA haplotypes supports a long history for P. pipistrellus s.str. in Europe, and the hypothesis that species with a broad ecological niche may have adapted and survived outside southern peninsula throughout the LGM.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

In this study the relationship between the North American monsoon, the Californian sea surface temperature (SST) cold pool, the Rocky Mountains and the North Pacific subtropical anticyclone is investigated using the Hadley Centre's atmospheric climate model, HadAM3. In 1996 Hoskins hypothesized that heating in the North American monsoon might be important for the maintenance of the summertime North Pacific subtropical anticyclone, since the monsoon heating may induce descent to the north-west of the monsoon in the descending eastern flank of the subtropical anticyclone. This descent is further enhanced by radiative cooling and is associated with equatorward surface winds parallel to the western coast of North America. These equatorward winds induce oceanic upwelling of cold water and contribute to the formation of the Californian SST cold pool, which may feed back on the anticyclone by further suppressing convection and inducing descent. More recently, Rodwell and Hoskins also investigated the global summer monsoon–subtropical anticyclone relationship. They examined the role that mountains play in impeding the progress of the low-level mid-latitude westerlies, either deflecting the westerlies northwards where they ascend along the sloping mid-latitude isentropes or deflecting them southwards forcing them to descend along the isentropes. In particular, the introduction of the Rockies into a primitive-equation model adiabatically induces descent in the eastern descending flank of the North Pacific subtropical anticyclone. These hypothesized mechanisms have been investigated using HadAM3, focusing on the possible suppression of convection by the Californian SST cold pool, the response of the North Pacific subtropical anticyclone to the strength of the North American monsoon and the ‘blocking’ of the mid-latitude westerlies by the Rocky Mountains. The role of the Rockies is examined by integrating the model with modified orography for the Rocky Mountains. Changing the height of the Rockies alters the circulation in a way consistent with the mechanism outlined above. Higher Rocky mountains force the westerlies southwards, inducing descent in the eastern flank of the subtropical anticyclone as the air descends along the sloping isentropes. The relationship between the North American monsoon and the North Pacific subtropical anticyclone is investigated by suppressing the monsoon in HadAM3. The suppression of the monsoon is accomplished by increasing the surface albedo over Mexico, which induces anomalous ascent on the eastward flank of the subtropical anticyclone and anomalous polewards surface winds along the western coast of the North American continent, also providing support for the above hypothesis. The removal of the Californian SST cold pool, however, has a statistically insignificant effect on the model, suggesting that in this model the feedback of the SST cold pool on the eastern flank of the anticyclone is weak.