24c1674b76c95bbe9bef9630961dcdf1 English series Subacoustech Ltd Dr J Nedwell Subacoustech Ltd Chase Mill Winchester Road Bishops Waltham Hampshire SO32 1AH jeremy.nedwell@subacoustech.com pointOfContact 2009-05-07 MEDIN Discovery Metadata Standard Version 2.3.5 urn:ogc:def:crs:EPSG::4326 OGP 2008, COWRIE, Measurement and assessment of background underwater noise and its comparison with noise from pin pile drilling operations during installation of the SeaGen tidal turbine device, Strangford lough 2008-09-04 publication 2008-01-01 creation 3213 http://data.offshorewind.co.uk/ This report has been prepared by Subacoustech Ltd for COWRIE. This report details a series of underwater noise measurements undertaken during drilling operations for the pin piles used to secure the quadropod base of the SeaGen tidal turbine device in Strangford Lough, Northern Ireland. The results have been interpreted in terms of the potential impact this noise may have on marine species. Background noise measurements were also undertaken during periods when the drilling was not being carried out to determine pre-existing ambient underwater noise levels in the region. It had been intended to include measurements of underwater noise generated by high pressure water jet cutting at the Strangford Lough site. The installation procedure for the construction project however, was changed and this technique was not required The Crown Estate +44 020 7851 5000 16 New Burlington Place London W1S 2HX United Kingdom enquiries@thecrownestate.co.uk http://www.thecrownestate.co.uk custodian Dr J Nedwell Subacoustech Ltd Subacoustech Ltd, Chase Mill, Winchester Road Bishops Waltham Hampshire SO32 1AH United Kingdom jeremy.nedwell@subacoustech.com subacoustech.com originator notPlanned pdf Marine Environmental Data and Information Network Metadata record availability 2012-01-11T07:46:54 revision Research The Crown Estate Renewable Energy Development Phases 2012-05-15T02:00:03 revision Research and Development Activity The Crown Estate Renewable Energy Development Areas 2012-05-15 revision 1 Acoustic noise in the water column Sound velocity and travel time in the water column SeaDataNet Parameter Discovery Vocabulary 2017-10-18 revision 104 no conditions apply eng biota environment -9.33312855790775 2.68743327033997 49.0399981037863 60.7672028638749 2008-09-04 2008-09-04 Origin: Subacoustech Ltd http://www.marinedataexchange.co.uk/search?q=#fq=fq%3DProject%253Amdecowrie1028 download https://www.marinedataexchange.co.uk/details/261/summary A link to the web service or dataset. https://www.marinedataexchange.co.uk A link to the general host site. dataset Measurements of background underwater noise during periods when no drilling was being carried out have indicated high levels of high frequency background noise are present in the Strangford Narrows region of Strangford Lough. It is thought that this is due to the high speed of tidal flow in the region generating noise by interaction of turbulent water with the sea bed and at the water surface. Measurements at ranges of 28 m to 2130 m from the drilling operation indicated that the unweighted, one second RMS Sound Pressure Levels varied from 105 to 139 dB re. 1 μPa. A fit to the measured data has indicated a Source Level for the drilling noise of 162 dB re. 1 μPa @ 1 m. The levels of underwater noise from the drilling operation are comparable with small vessel noise, and considerably lower than the levels of noise generated by other piling techniques such as impact piling or vibro-piling.