Alternate title

GB001314

Date (Publication)

2018-04-26

Date (Creation)

2014-06-06

Citation identifier

EMODnetSeabedHabitats / GB001314

Point of contact

Organisation name	Individual name	Electronic mail address	Role
DEFRA		open@defra.gsi.gov.uk	Owner
Natural England		enquiries@naturalengland.org.uk	Custodian

GEMET - INSPIRE themes, version 1.0

• Habitats and biotopes

http://inspire.ec.europa.eu/codelist/ReferenceHabitatTypeSchemeValue

• Eunis

Use limitation

┬® DAERA. Data may be re-used under the terms of the Open Government Licence.

Use limitation

geossAttribution

Access constraints

Other restrictions

Other constraints

no limitation

Spatial representation type

Vector

Denominator

2000

Language

English

Topic category

• Biota
• Oceans

Begin date

2013-01-19

End date

2013-03-21

Reference system identifier

EPSG / WGS 84 (EPSG:4326) / 7.9

Topology level

Geometry only

Distribution format

Name	Version
ESRI Shapefile	1.0

OnLine resource

Protocol	Linkage	Name
WWW:LINK-1.0-http--link	http://randd.defra.gov.uk/Document.aspx?Document=12834_IslesofScilly_BristowtotheStonesrMCZ_SiteReport_v6.pdf	Isles of Scilly Sites: Bristows to the Stones rMCZ Post-survey Site Report
OGC:WMS	https://ows.emodnet-seabedhabitats.eu/geoserver/emodnet_view_maplibrary/wms?	gb001314
OGC:WFS	https://ows.emodnet-seabedhabitats.eu/geoserver/emodnet_open_maplibrary/wfs?	gb001314
WWW:LINK-1.0-http--link	https://files.emodnet-seabedhabitats.eu/data/EMODnetSBHsurvey_GB001314.zip	EMODnet Seabed Habitats download

Hierarchy level

Dataset

Statement

New multibeam bathymetry and backscatter data (300 kHz system) were acquired for the purposes of mapping the rMCZ area. The survey at the Isles of Scilly: Bristows to the Stones rMCZ was carried out between 3rd January ÔÇô 25th January 2013 on the RV Cefas Endeavour cruise CEND 01/13Y (Ware et al., 2013). The acoustic survey lines were planned at the necessary spacing to allow 100% MBES coverage to be achieved with sufficient data overlap in accordance with International Hydrographic Organisation (IHO) standard Order 1a. It should be noted that, due to the presence of shallow rock in the easternmost sector of the rMCZ area, only 25.1 km┬▓ of 31.6 km┬▓ site was accessible to the survey vessel (Appendix 2). CARIS HIPS was utilized to process the bathymetry data and Fledermaus Geocoder Toolkit (FMGT) was used to produce fully compensated and corrected backscatter mosaic and were exported as Floating Point Geotiff files for further analysis. Both bathymetry and backscatter were gridded at 2 m resolution for analysis (see Appendix 2 for bathymetry and backscatter images derived from the acoustic data).

Ground-truth samples were collected from 28 stations which were positioned to provide coverage across the full range of strata identified using the MBES bathymetry and backscatter data (Figure 2; Appendix 1) (Ware et al., 2013). Ground-truthing was accomplished by the acquisition of seabed photographs (digital stills captured from recorded video) along short profiles. There were no physical sediment samples recovered from the rMCZ area due to the predominance of hard/rocky substrates.

Video observations were made with a Drop Camera (DC) system comprising a rectangular frame fitted with a video camera with the capability to also capture still images (Figure 2). Illumination was provided by two Cefas high intensity LED spotlights and a flash unit. The camera was fitted with a four-spot laser-scaling device to provide a reference scale in the video image. Set-up and operation followed the MESH ÔÇÿRecommended Operating Guidelines (ROG) for underwater video and photographic imaging techniquesÔÇÖ. Drop-camera deployments lasted a minimum of 10 minutes, with the vessel executing a controlled drift at ~ 0.5 knots (~0.25 m s -1 ) across a 50 m ÔÇÿbullringÔÇÖ centred on the sampling station. Stills images were captured at regular one minute intervals and opportunistically when specific features of interest were encountered. Video and still images were analysed by Envision Mapping Ltd. (2013) following an established protocol developed and used by Cefas (Coggan et al., 2007; JNCC, in prep.; see Annex 5). The time and position at which each still was taken was noted from the metadata provided by Cefas. The physical and biological characteristics were viewed at normal and greater than normal magnification, noting details of substrate types and species present. A broadscale habitat type, habitat FOCI (if applicable) and biotope was then assigned to each still image according to ÔÇ£The Marine Habitat Classification for Britain and Ireland Version 04.05ÔÇØ.

All new maps and their derivatives have been based on a WGS84 datum. A new habitat map for the site was produced by analysing and interpreting the available acoustic data (as detailed above) and the ground-truth data collected during the dedicated survey of this site. The process is a combination of two approaches, autoclassification (image analysis) and expert interpretation, as described below. The routine for auto-classification is flexible and dependent on site-specific data, allowing for application of a bespoke routine to maximise the amount of acoustic data available.

The technical quality of the updated habitat map was assessed using the MESH ÔÇÿConfidence AssessmentÔÇÖ Tool1 , originally developed by an international consortium of marine scientists working on the MESH (Mapping European Seabed Habitats) project. This tool considers the provenance of the data used to make a biotope/habitat map, including the techniques and technology used to characterise the physical and biological environment and the expertise of the people who had made the map. In its original implementation, it was used to make an auditable judgement of the confidence that could be placed in a range of existing, local biotope maps that had been developed using different techniques and data inputs, but were to be used in compiling a full coverage map for north-west Europe. Where two of the original maps overlapped, that with the highest MESH confidence score would take precedence in the compiled map.

Metadata

File identifier

23568eee-1eb4-48c9-bb80-0c0956f986a6 XML

Metadata language

English

Character set

MD_CharacterSetCode_utf8

Hierarchy level

Dataset

Date stamp

2020-01-15T12:29:48

Metadata standard name

ISO19115

Metadata standard version

2003/Cor.1:2006

Metadata author

Organisation name	Individual name	Electronic mail address	Role
JNCC		HabitatMapping@jncc.gov.uk	Point of contact