06210bfc4d1dc4e4076ab7d528d857b9 English c25edeeb492d845621e3db3d997fc7e9 dataset Leoni Adams Data Archive for Seabed Species and Habitats (DASSH) 01752 633102 01752 633291 Marine Biological Association of the UK, The Laboratory, Citadel Hill Plymouth PL1 2PB dassh.enquiries@mba.ac.uk pointOfContact 2019-08-16 MEDIN Discovery metadata standard 2.3.8 urn:ogc:def:crs:EPSG::23031 2007 Shell UK Exploration and Production Ltd GAA007 Environmental Survey Gannet Field UKCS Blocks 21/25, 21/30, 22/21 and 22/26a 2007-06-30 publication 2007-06-01 creation 2007-06-30 revision UK00A_GAA07 http://dassh.ac.uk Environmental Survey. Gannet Field. UKCS Blocks 21/25, 21/30, 22/21 and 22/26a Mick Borwell Oil and Gas UK Environmental Issues Director +44 (0)20 7802 2400 +44 (0)20 7802 2401 2nd Floor 232-242 Vauxhall Bridge Road London SW1V 1AU info@oilandgasuk.co.uk originator Becky Seeley Data Archive for Seabed Species and Habitats (DASSH) 01752 633102 01752 633291 Marine Biological Association of the UK, The Laboratory, Citadel Hill Plymouth PL1 2PB dassh.enquiries@mba.ac.uk custodian unknown Database Marine Environmental Data and Information Network Habitats and biotopes Human health and safety Land use Species distribution GEMET - INSPIRE themes, version 1.0 2008-01-06 revision Macroalgae generic abundance in water bodies Zoobenthos generic abundance Industrial discharges Habitat characterisation Industrial activity SeaDataNet P021 parameter discovery vocabulary 2009-11-16 revision Habitats and biotopes INSPIRE THEMES 2011-02-16 creation Released under DASSH terms and conditions otherRestrictions Released under DASSH terms and conditions https://www.dassh.ac.uk/terms-and-conditions 200 English biota health planningCadastre biota Charting Progress 2 Sea Areas 2009-06-18 creation Eastern Channel Charting Progress 2 Sea Areas 2009-06-18 creation Western Channel and Celtic Sea 0.8000 1.2000 57.0000 57.3330 2007-06-01 2007-06-30 Dan Lear Data Archive for Seabed Species and Habitats (DASSH) 01752 633102 01752 633291 Marine Biological Association of the UK, The Laboratory, Citadel Hill Plymouth PL1 2PB dassh.enquiries@mba.ac.uk distributor dataset Environmental Survey. Gannet Field. UKCS Blocks 21/25, 21/30, 22/21 and 22/26a TAKEN FROM REPORT SUMMARY OF SURVEY RESULTS Location All coordinates in this report are based on the International Spheroid 1924, European Datum 1950. Grid coordinates are on the Universal Transverse Mercator Projection, Central Meridian 0. Study Area: In June 2007, Fugro Survey Limited (FSLTD) were subcontracted by Fugro Rovtech Limited to performed environmental survey in the Gannet field, in the Central North Sea, UKCS blocks 21/25, 21/30, 22/21 and 22/26a. The field consists of a cluster of seven oil and gas fields (namely Gannet A, B, C, D, E, F and G). The survey was performed in order to investigate the effects of existing development in the area and to establish a baseline for future development. Bathymetry: Tidally uncorrected single beam echosounder spot depths recorded at sampling locations during the current study ranged from 93 m to 100 m, indicating an essentially flat seabed within the survey area. Seabed Features: Full seabed features information was not available for the survey area. However, a previous geophysical survey for a pipeline route from Bittern to Gannet A in the centre of the Gannet field (Fugro Geoteam Limited report number M2032.11, Shell Expro report number P97-146 / 31) found surficial sediments along the route to comprise fine to coarse, occasionally clayey and / or silty sand. Environmental Survey Strategy: A total of 38 stations were sampled using a 0.1 m2 Day grab with one or three physicochemical replicates retained for analysis and three macrofaunal replicates obtained at 21 of the 38 stations. Seabed photography was undertaken at the required locations for groundtruthing purposes. Granulometry: The sediments were similar across the survey area ranging from poorly to very poorly sorted, fine to very fine sand, with the exception of station D4, which was classified as very poorly sorted medium silt. Mean phi ranged from 2.52 to 3.69 (station C9 and C4, respectively), while station D4 showed a mean phi of 5.27. The sorting coefficient ranged from 1.03 (stations D6 and Ref2) to 2.19 (station D4). In general variation in the particle size composition of sediments within the survey area appeared to relate to the proximity to the historic well locations. Drill cuttings were observed in many of the samples located adjacent to the historic well locations i.e. A3, A4, C4 and D2 to D5. Comparison of granulometry data with 1990 survey data showed that levels of fines appeared to have increased across the entire survey, although this is probably due to a change in methodology (the current survey utilised wet sieving techniques followed by laser diffraction). However, it was considered significant that the areas adjacent to the historic well locations showed a disproportionate increase in fines, presumed to be due to the presence of drill cuttings, which were not present in the 1990 baseline survey. Organic Carbon: TOM for the majority of sediments from the survey area ranged from 1.2% to 2.9% (stations A10 and C2, respectively). Substantially higher levels of loss on ignition were recorded for stations adjacent to historic well locations i.e. D4 and C4, at 4.6% including station A3 at 4.0%. Several other stations showed elevated levels of TOM, between approximately 2.3% and 2.9%, reflecting their proximity to areas of drilling activity (stations A1, C5, D2, D3, D5, C2, C7 and C8).