2256bd633e0459e68888012151ce79c8 eng series The Crown Estate mde@thecrownestate.co.uk marinedataexchange.co.uk pointOfContact 2014-08-19 MEDIN Discovery Profile 2.3.8 EPSG::4326 2004, Envision Mapping Ltd, Lynn, Lincs and Inner Dowsing Offshore Windfarms, Sabellaria Spinulosa Survey 2005-01-01 publication 3176 http://data.offshorewind.co.uk/ This project presents survey information to determine seabed conditions pre- and post-construction for three offshore wind farms off the Lincolnshire coast (Lincs, Lynn and Inner Dowsing). This report presents the survey results and analysis of the pre-construction phase. The purpose of the survey was to:- • Identify the occurrence of Sabellaria spinulosa and, if present, describe the extent of development of reef communities likely to be of conservation importance; • Identify of other benthic habitats that might be sensitive to the construction and operation of wind farms; • Provide a baseline from which the effects of construction can be assessed, especially on any Sabellaria spinulosa; • Survey the seabed bathymetry. The survey strategy stipulated that grab sampling was to be avoided where reefs were detected. No substantial reef structures were detected on the sidescan sonar and this permitted a more representative grab sampling program. 30 samples were taken for sediment size and infauna. The infauna were analysed using multivariate techniques and trend analysis in a geographic information system (GIS). The sediments were classed into categories and these used to classify the AGDS data. One of the ‘sediment’ classes was the biogenic sediment Sabellaria spinulosa tubes. The classification predicted that the location most likely to support Sabellaria spinulosa reef was at the margin of the stony/gravel shoal. Although no substantial Sabellaria spinulosa reefs were found, dense aggregations were observed and the predicted distribution of habitats most likely to support this biogenic habitat, derived from the interpretation of the acoustic data, lay on the eastern margin of the Lynn, Lincs and Inner Dowsing sites. This also coincided with high species diversity. The majority of the shallow gravel shoal which makes up the proposed wind farm sites support low to moderate diversity epifaunal biotopes typical of the southern North Sea and are of low conservation significance when taken in their wider geographic context. Centrica Renewable Energy Ltd Offshore Wind Development Manager 1st Floor Millstream East Maidenhead Road, Windsor laura.jeffs.@centrica.com www.centricaenergy.com/renewables custodian Centrica Renewable Energy Ltd Offshore Wind Development Manager 01753 431289 1st Floor Millstream East Maidenhead Road, Windsor laura.jeffs.@centrica.com www.centricaenergy.com/renewables originator notPlanned Marine Environmental Data and Information Network Marine Environmental Data and Information Network Offshore area of search The Crown Estate Renewable Energy Development Areas 2012-05-15 revision 1 Offshore Cable Corridor Zone search area The Crown Estate Renewable Energy Development Areas 2012-05-15 revision 1 Pre-Construction monitoring The Crown Estate Renewable Energy Development Phases 2012-05-15 revision 1 Acoustic noise in the water column Sediment grain size parameters Horizontal velocity of the water column (currents) Habitat characterisation Habitat extent Seabed photography Bathymetry and Elevation Side-scan sonar SeaDataNet Parameter Discovery Vocabulary 2014-10-09 revision 86 http://www.marinedataexchange.co.uk/pages/terms-of-use.aspx copyright copyright http://www.marinedataexchange.co.uk/pages/terms-of-use.aspx http://www.marinedataexchange.co.uk/pages/terms-of-use.aspx eng biota environment 0.447657201555526 0.52389494189844 53.1644804509372 53.2713172395977 2004-09-01 2004-11-30 http://www.marinedataexchange.co.uk/search?q=#fq=fq%3DProject%253Amde1r12idll002 download https://www.marinedataexchange.co.uk/details/726/summary A link to the web service or dataset. https://www.marinedataexchange.co.uk A link to the general host site. series Two acoustic systems were used to survey the area: a RoxAnn™ AGDS system and a GeoSwath™ interferometric swath bathymetric system. This proved to be an efficient use of vessel time in that AGDS and GeoSwath data (side scan, swath bathymetry and backscatter) were collected simultaneously. The high resolution of the swath system gives information on bedform features as well as general bathymetry and major seabed sediment categories. The system has accurate motion-sensing so that all final outputs are corrected for motion and tide. Although AGDS gives poor resolution, it supplements swath data by giving greater discrimination between different sediment types. The two systems can be operated at a vessel speed of around 10-12km/hr, which enabled areas to be covered relatively rapidly.