As part of the UK Department of Trade and Industry's (DTI's) ongoing sectorial Strategic Environmental Assessment a seabed survey program (SEA4) was undertaken in July/August 2002 for the UKCS areas to the North of Shetland from MV Kommandor Jack. This report summarises the sediment total hydrocarbon and aromatic data generated from the analyses of select samples from the main study areas.

As part of the UK Department of Trade and Industry's (now Department of Energy and Climate Change) ongoing sectorial Strategic Environmental Assessment a seabed survey programme (SEA5) was undertaken between August and early October 2003 for the UKCS areas lying between Scotland and Orkney and Shetland. This report summarises the sediment total hydrocarbon and aromatic data generated from the analyses of selected samples from the study areas detailed: Fair Isle - 46 to 198m water depth; Outer Moray Firth A - 61 to 171m; Outer Moray Firth B - 57 to 100m; Sandy Riddle - 30 to 70m; Smith Bank - 39m; Southern Trench - 76 to 252m.

As part of the UK Department of Trade and Industry's (now Department of Energy and Climate Change) sectorial Strategic Environmental Assessment (SEA) programme a seabed survey programme (SEA2) was undertaken in May/June 2001 for areas in the central and southern North UKCS. This report summarises the sediment total hydrocarbon and aromatic data generated from the analyses of selected samples from three main study areas: area 1 (sand bank/wave study areas, Norfolk Coast), Area 2 (Dogger Bank transects) and Area 3 (South Fladen pockmark study areas of the central North Sea).

Sediment samples were collected from selected areas of the southern North Sea as part of the ongoing Department of Trade and Industry's (now Department of Energy and Climate Change) Strategic Environmental Assessment (SEA2). The aim of the survey was to describe the physical, chemical and biological characteristics of a range of offshore sandbanks and pockmarks (more than 12 km from the coast). The survey focused on three main study areas in the southern North Sea: the Dogger Bank study area; the South Fladen Pockmark study area and a major sand bank area off the coasts of Norfolk and Lincolnshire. This report presents the following sediment data: Total hydrocarbon and n-alkane concentrations; 2 to 6 ring polynuclear aromatic hydrocarbons (PAH) content; selected metals concentrations.

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). Methane-derived authigenic carbonate (MDAC) is formed as a consequence of the anaerobic oxidation of methane by consortia of bacteria. MDAC develops as a rock-like concretion when a carbonate precipitate cements normal seabed sediment; the carbon of this carbonate is derived from methane. It occurs as crusts or slabs at the seabed, or as exposed lumps. The occurrence of MDAC is evidence of methane seepage, although the seepage is not necessarily going on at the present time. Large quantities of MDAC indicate that methane seepage has occurred over a prolonged period of time. 'Submarine structures formed by leaking gas' have been identified by the European Commission's Habitats Directive as habitats worthy of protection. The distribution of MDAC in UK waters is poorly known. This report summarises the available information relevant to MDAC in the SEA6 area, including data acquired by surveys specifically conducted in support of this SEA in 2004. Carbon isotope data for samples recovered in 2004 have confirmed that the cemented hard grounds from two of the areas studied, Texel 11 and Holden's Reef, are composed of MDAC.

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.

As part of Strategic Environmental Assessment SEA1, sediment samples were collected at the request of the Department of Trade and Industry (now Department of Energy and Climate Change) from Charles Darwin between July and September 2000. Samples for a number of chemical and biological analyses were collected. The analysis undertaken on the sediment samples collected were: total organic carbon and total organic nitrogen; total hydrocarbon and n-alkane content; and 2 to 6 ring polynuclear aromatic hydrocarbons (PAH) content. Excel files containing the data are also available.