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    This report on underwater noise is a contribution to the Strategic Environmental Assessment (SEA7) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). This report initially gives a general introduction to underwater ambient noise and the underlying mechanisms that generate sound. The report then identifies a number of sources of underwater acoustic noise, describes the characteristics of the noise including frequency content, levels and variability, and also identifies the current state of knowledge on each source. In all cases the sources are considered in the context of the SEA 7 area. Mechanisms that can modify the ambient sound levels are described. The dominant noise sources in the SEA 7 area are identified. Recommendations are then made for the methodology to be used to obtain meaningful characterisation of noise levels in order to establish baseline levels. The report then goes on to present an analysis of measured ambient noise data in the SEA 7 area, model predictions of spectrum levels, and compares the measured and modelled data.

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    This report is a contribution to the Strategic Environmental Assessment (SEA6) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). This report reviews the many different sources of underwater noise, both natural and anthropogenic, that combine to provide the background noise levels in which marine organisms need to survive throughout the SEA6 region. The sources of sound combine together in a complex manner resulting in significant spatial and temporal variations in the noise field. A map of the dominant noise sources in the Irish Sea is shown, indicating that man-made noise is the dominant source of noise over about 70% of the area. Shipping noise is likely to be dominant across large parts of the SEA6 area. To fully characterise the ambient noise field in the SEA6 area would require multiple measurements at a large number of locations over a period of a year. However, a considerably lower cost approach would be to characterise each sound source and to use this with occurrence statistics for each source to model the ambient noise field across the region. The advantages and disadvantages of the acoustic modelling approach are discussed.

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    This report is a contribution to the Strategic Environmental Assessment (SEA6) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). This report describes the physical oceanography of the Irish Sea from St George's Channel in the south to the North Channel and the Clyde Sea in the north. The report covers the topography and depth of the sea floor, the tides, the impact of storms, stratification and its consequences and the mean circulation, all with a view to mean and extreme conditions. The predominant dynamical process is the semi-diurnal tides, with areas of both high and low energy embraced. Superimposed on this is the full range of water column structure areas that are well mixed throughout the year; areas that stratify thermally in summer; areas of freshwater influence from river discharges, leading both to nearshore density gradients and stratification; frontal regions between the well-mixed and stratified regions. The movement of the water and the amount of mixing prescribe physical effects, such as forces on structures and the movement and dispersion of contaminants, but also significantly influence biogeochemical processes including sediment erosion / deposition and movement, particularly of suspended sediment, benthic exchanges and primary productivity (via stratification, nutrient exchanges and light levels).

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    This report is a contribution to the Strategic Environmental Assessment (SEA7) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). The report concentrates on reviewing existing data and published sources, rather than attempt a quantitative baseline of wrecks and casualties. There is a comprehensive corpus of legislation, plans and polices concerned with the protection of the submerged maritime archaeological resource within the SEA 7 study area. The study outlines the known history of maritime activity within the SEA 7 area. Despite being an extremely large body of water that at times can produce dangerous sea and weather conditions, and encompasses the rugged coastlines of western Scotland and Northern Ireland, the area has been used extensively by seafarers from at least the Mesolithic (from 9000 BC) up to present times. During each time period there has been evidence of human activity within the SEA 7 area, often demonstrated by the discovery of maritime archaeological remains. The waters between the north east of Ireland and Scotland have been used as a means of communication throughout the centuries. Previous investigations of maritime archaeological remains within the SEA 7 area are discussed in the report. The spatial distribution of submerged archaeological remains is discussed, and comments are made on the limitations of any mapped baseline of data. The study concludes with a comment on the potential impacts of oil and gas activities on the submerged maritime archaeological resource and suggests possible monitoring methodologies.

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    This report is a contribution to the Strategic Environmental Assessment (SEA7) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change) and describes the hydrography of the SEA7 area. SEA7 lies across the northern end of the Atlantic Meriodional Overturning Circulation and contains a number of major oceanic currents carrying surface water northward across the whole region and returning cold Artic water around the foot of some of its slopes.

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    This report is a contribution to the Strategic Environmental Assessment (SEA7) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change).The class Cephalopoda comprises three major divisions, of which two: Decapoda (squids and cuttlefish) and Octopoda (octopods) are represented in the SEA 7 Area. They are highly developed, but short-lived molluscs with rapid growth rates. They are important elements in marine food webs and interact significantly with marine mammals, seabirds and commercially exploited finfish species. They also represent a promising future fishery resource in terms of market value, abundance and growth potential. At present, only an estimated 10% of exploitable stocks are utilised worldwide. There are six marketable squid species that occur in the SEA 7 Area. These belong to the long-fin (loliginid) and short-fin (Ommastrephid) squids the two most important exploited families of decpods. In the SEA 7 Area, only one species, Loligo forbesi is commercially exploited on a regular basis, although there are significant landings of other species on occasion. The closely related Loligo vulgaris sometimes appears in catches and the small Alloteuthis subulata is thought to be naturally abundant and an important food item in the marine ecosystem. There are other important species represented in the SEA 7 Area. These include cuttlefish, octopods, sepiolids and a number of deep-water species. Most of these are marketable and may be ecologically important. Large fisheries for some of these species, particularly octopods and cuttlefish operate in European waters further south, but they are not currently exploited in the SEA 7 Area.

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    As part of the Department of Trade and Industry's (now Department of Energy and Climate Change) Strategic Environmental Assessment (SEA6) a geophysical survey was undertaken on SV Meridian SEA6 Survey A (or Leg 1) in the eastern Irish Sea mainly in the central region between the Isle of Man and Cumbrian coast. The aims of the data collection were to survey geographical areas where the regional BGS maps and other published data indicated knowledge gaps in the understanding of regional seabed sediment distribution patterns and processes; Create high resolution bathymetric, backscatter and superficial geological data suitable for mapping banks, deeps, transitions between seabed coarse and fine sediments and the mid-shelf and nearshore environments; Generate data suitable for calibration of previous interpretations of net bedload sediment transport directions. Multibeam, sidescan sonar and chirp seismic data were collected. 14 gridded processed multibeam files are available. Raw data are also available.14 mosaic sidescan tif files available. Raw seismic data also available. Cruise reports are available.

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    As part of Strategic Environmental Assessment SEA1, sediment samples were collected from the area designated as the White Zone at the request of the Department of Trade and Industry (DTI) as part of its sea-going research activities during summer 2000. The objective of the cruise was to provide a description of the current state of the seabed in the survey area, while providing baseline environmental data and identifying larger-scale environmental patterns and processes. The survey programme was conducted from Charles Darwin between July and September 2000, with samples for a number of chemical and biological analyses being collected. An Excel file containing detail of species abundance is available.

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    Sediment samples were collected during the Strategic Environmental Assessment SEA1 (White Zone) Environmental Survey in 2000 at the request of the Department of Trade and Industry (now Department of Energy and Climate Change). This data report collates all the results generated by Gardline Survey Limited. The analysis undertaken on the sediment samples were: total organic carbon and total organic nitrogen; total hydrocarbon and n-alkane content and polycyclic aromatic hydrocarbons (PAH) content.

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    As part of as part of the Department of Trade and Industry's (now Department of Energy and Climate Change) Strategic Environmental Assessment (SEA2) a geophysical survey was carried out in three different quarters of the North Sea: Norfolk Coast (Area 1), Dogger Bank (Area 2) and Fladen Ground (Area 3) from Kommandor Jack SEA2 Survey Leg 1, 2001. Multibeam, sidescan sonar and chirp seismic data were collected. The survey was carried to identify potential offshore Special Areas of Conservation (SACs). It was necessary to acquire data on specific features identified in the EU Habitats Directive, such as sandbanks and pockmarks, some of which might subsequently be defined as SACs. The survey was carried out in two legs. Leg one included the geophysical surveys in three different quarters of the North Sea as well as the charting which was used to guide the sampling and photographic work on the second leg. The following data are available - 25 files of processed multibeam data. Screenshots of backscatter processing are also available. Side-scan mosaics. Images are available from 15 boxes. Processed seismic data. Cruise report