e3111bef-cae8-7285-e053-0937940a441b English dataset British Geological Survey (BGS) +44 (0)131 667 1000 +44 (0)131 668 4140 The Lyell Centre, Research Avenue South Edinburgh EH14 4AP UK enquiries@bgs.ac.uk pointOfContact 2026-04-17 MEDIN Discovery Metadata Standard Version 2.3.5 www.epsg.org 2005 revision urn:ogc:def:crs:EPSG::4326 OGP Welsh Fishermen’s Association (WFA-CFC) (WFACPC) 2021 Welsh Fishermen’s Association - Cymdeithas Pysgotwyr Cymru (WFA-CPC) Severn Esturary/Môr Hafren SAC Benthic and Geophysical surveys 2020-08-28 publication BGS_CMD_REF1432 British Geological Survey Within the project (WFA-CPC EMFF Protecting Our Seas), benthic and geophysical surveys were undertaken in the Severn Esturary/Môr Hafren SAC to explore the location of Sabellaria alveolata reefs, and collected bathymetry, sidescan sonar, AGDS and acoustic imagery data (ARIS) to identify areas of variable ground or potential features. A ten-day survey was undertaken in July 2020 to collect broad-scale acoustic data using an interferometric swath bathymetric system (GeoSwath Plus) and Acoustic Ground Discrimination System (RoxAnn™ AGDS). Twelve secondary survey areas were selected to be investigated in greater detail using high frequency sidescan sonar and an Acoustic Resonance Inspection System (ARIS Explorer 3000) camera in a second ten-day survey conducted in August 2020 (https://www.envision.uk.com/wp-content/uploads/2022/03/2018-1008-NRW-WFA-Protecting_Our_Seas_Final_Report_20210201.pdf) The data sets include: SSS (.tif) collected using Trident SeaStar MBES (.xyz) collected using GeoSwath Plus, AGDS (.csv and .asc) collected using RoxAnn™ AGDS ARIS imagery (.png and .mp4) collected using ARIS Explorer 3000 camera Shapefiles (.shp etc) British Geological Survey (BGS) +44 (0)131 667 1000 +44 (0)131 668 4140 The Lyell Centre, Research Avenue South Edinburgh EH14 4AP UK enquiries@bgs.ac.uk custodian Welsh Fishermen’s Association (WFA-CFC) offshoredata@bgs.ac.uk originator notPlanned NDGO0001 Geology GEMET - INSPIRE themes, version 1.0 2008-06-01 publication soil and sediment crust SeaVoX Vertical Co-ordinate Coverages (L131) 2010-05-18 revision otherRestrictions restricted otherRestrictions The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused. unrestricted use, copyright acknowledgement - To use the data, permission must be requested from data owners,Welsh Fishermen’s Association - Cymdeithas Pysgotwyr Cymru (WFA-CPC). No data or information from these archived datasets may be reproduced, transmitted or copied without the permission of the owners, the Welsh Fishermen’s Association - Cymdeithas Pysgotwyr Cymru (WFA-CPC). grid 5 English geoscientificInformation Charting Progress 2: Regional Sea Boundaries 2009-06-18 creation Western Channel & Celtic Sea BGS Gazetteer 2026-04-17 revision Bristol Channel The SeaVoX Salt and Fresh Water Body Gazetteer: Sub-Ocean Category 1954-01-01 creation BRISTOL CHANNEL -3.1339 -3.0335 51.4466 51.5004 2020-07-19 2020-08-28 British Geological Survey (BGS) +44 (0)131 667 1000 +44 (0)131 668 4140 The Lyell Centre, Research Avenue South Edinburgh EH14 4AP UK enquiries@bgs.ac.uk distributor http://mapapps2.bgs.ac.uk/geoindex_offshore/home.html?cruise=2021_WFA-CPC WWW:LINK-1.0-http--link BGS Offshore Geoindex GeoIndex allows users to search for information about BGS data collections covering the UK and other areas world wide. Access is free, the interface is easy to use, and it has been developed to enable users to check coverage of different types of data and find out some background information about the data. More detailed information can be obtained by further enquiry through the website. search dataset INSPIRE Implementing rules laying down technical arrangements for the interoperability and harmonisation of unknown theme 2011 publication See the referenced specification false Envision was contracted to undertake the survey on behalf of Welsh Fishermen’s Association (WFA-CFC). This resource is part of a multidisciplinary series 2019-2021 WFA-CPC EMFF PROTECTING OUR SEAS PROJECT (see https://portal.medin.org.uk/portal/start.php#details?tpc=010_d8f12e7ea0689c2c570d15b48a283367). Broad-scale acoustic data was collected using the interferometric swath bathymetric system (GeoSwath Plus) and an Acoustic Ground Discrimination System (RoxAnn™ AGDS). A series of survey lines were planned to incorporate four survey blocks, traversing parallel survey lines throughout each block. The line spacing was 50m and infill line spacing was 25m, with infill used in shallow areas where needed. Survey lines were run to a navigable safe depth and no shallower, at approx. 4knts. At all 12 secondary survey areas, high frequency (1 MHz) sidescan sonar data were collected by deploying the tow fish from the stern of the vessel and traversing parallel lines at a constant speed. The underwater sonar camera system (ARIS 3000) was then towed over the same areas as the vessel drifted with the current/wind at slack tides. Start, end and a continuous log of GPS positions were recorded. Keywords: Welsh Fishermen’s Association - Cymdeithas Pysgotwyr Cymru (WFA-CPC), Severn Esturary/Môr Hafren SAC, Benthic and Geophysical surveys, Sabellaria alveolata, Reef, biogenic, acoustic data, interferometric swath bathymetric system, bathymetry, sidescan sonar, high frequency sidescan sonar, Acoustic Ground Discrimination System (RoxAnn™ AGDS), acoustic imagery data, Acoustic Resonance Inspection System (ARIS Explorer 3000) camera, acoustic reflectance, variable ground, feature identification, Trident SeaStar, fishing activity data.