{ "type":"Feature", "properties":{ "cruise_id":1432.0, "mdfileid_nerc_guid":"e3111bef-cae8-7285-e053-0937940a441b", "cruise":"2021_WFA-CPC", "cruise_alias":null, "restitle":"2021 Welsh Fishermen\u2019s Association - Cymdeithas Pysgotwyr Cymru (WFA-CPC) Severn Esturary/M\u00f4r Hafren SAC Benthic and Geophysical surveys", "ship":"Celtic Wildcat", "client":"Welsh Fishermen\u2019s Association (WFA-CFC)", "contractor":"Envision", "cruise_area":"CP2 Regional Sea Boundaries: Western Channel & Celtic Sea, Offshore 1:250k: Bristol Channel, SeaVoX Sub-Ocean: BRISTOL CHANNEL", "abstract":"Within the project (WFA-CPC EMFF Protecting Our Seas), benthic and geophysical surveys were undertaken in the Severn Esturary/M\u00f4r 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.\r\n\r\nA 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\u2122 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)\r\n\r\nThe data sets include:\r\nSSS (.tif) collected using Trident SeaStar MBES (.xyz) collected using GeoSwath Plus, AGDS (.csv and .asc) collected using RoxAnn\u2122 AGDS ARIS imagery (.png and .mp4) collected using ARIS Explorer 3000 camera Shapefiles (.shp etc)", "additional_info":"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\u2122 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.\r\nAt 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.\r\n Keywords: Welsh Fishermen\u2019s Association - Cymdeithas Pysgotwyr Cymru (WFA-CPC), Severn Esturary/M\u00f4r 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\u2122 AGDS), acoustic imagery data, Acoustic Resonance Inspection System (ARIS Explorer 3000) camera, acoustic reflectance, variable ground, feature identification, Trident SeaStar, fishing activity data", "nav_equip_type":null, "geophys_equip_type":null, "samp_equip_type":null, "start_date":"2020-07-19T00:00:00", "start_date_est":"Real", "end_date":"2020-08-28T00:00:00", "end_date_est":"Real", "confidentiality":"unclassified (open file)", "accessuse_restric":"unrestricted use, copyright acknowledgement", "terms_of_use":"To use the data, permission must be requested from data owners,Welsh Fishermen\u2019s 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\u2019s Association - Cymdeithas Pysgotwyr Cymru (WFA-CPC).", "terms_of_use_url":null, "cruise_data_url":"http://webapps.bgs.ac.uk/services/ngdc/accessions/index.html#item174189" }, "id":1432.0, "geometry":{ "type":"MultiPolygon", "coordinates":[ [ [ [ -3.11948770573732, 51.4650275993711 ], [ -3.13391488909013, 51.453659360874894 ], [ -3.1244451537308198, 51.4466379665434 ], [ -3.10747251883473, 51.455947114180795 ], [ -3.11948770573732, 51.4650275993711 ] ] ], [ [ [ -3.07325165614165, 51.464905738476496 ], [ -3.07451411209111, 51.4738618668647 ], [ -3.0888550122038296, 51.47307238152659 ], [ -3.08772069102609, 51.464066715821495 ], [ -3.07325165614165, 51.464905738476496 ] ] ], [ [ [ -3.04634151793855, 51.471878834318794 ], [ -3.05381238884485, 51.488931045966304 ], [ -3.0755412417277697, 51.4852169074452 ], [ -3.06806307733222, 51.4681663273299 ], [ -3.04634151793855, 51.471878834318794 ] ] ], [ [ [ -3.04051938185913, 51.5003701306894 ], [ -3.05060706650137, 51.493863079908294 ], [ -3.04383022022179, 51.4897826583644 ], [ -3.03347305086607, 51.49641996632089 ], [ -3.04051938185913, 51.5003701306894 ] ] ] ] }, "prev":1427.0, "next":1436.0, "links":[ { "type":"application/json", "rel":"root", "title":"The landing page of this server as JSON", "href":"https://ogcapi.bgs.ac.uk?f=json" }, { "type":"text/html", "rel":"root", "title":"The landing page of this server as HTML", "href":"https://ogcapi.bgs.ac.uk?f=html" }, { "rel":"self", "type":"application/geo+json", "title":"This document as JSON", "href":"https://ogcapi.bgs.ac.uk/collections/offshore-survey-overview/items/1432?f=json" }, { "rel":"alternate", "type":"application/ld+json", "title":"This document as RDF (JSON-LD)", "href":"https://ogcapi.bgs.ac.uk/collections/offshore-survey-overview/items/1432?f=jsonld" }, { "rel":"alternate", "type":"text/html", "title":"This document as HTML", "href":"https://ogcapi.bgs.ac.uk/collections/offshore-survey-overview/items/1432?f=html" }, { "rel":"collection", "type":"application/json", "title":"Offshore Survey Overview", "href":"https://ogcapi.bgs.ac.uk/collections/offshore-survey-overview" }, { "rel":"prev", "type":"application/json", "href":"https://ogcapi.bgs.ac.uk/collections/offshore-survey-overview/items/1427?f=json" }, { "rel":"next", "type":"application/json", "href":"https://ogcapi.bgs.ac.uk/collections/offshore-survey-overview/items/1436?f=json" } ] }