Alternate title

GB001546

Date (Publication)

2018-04-30

Date (Revision)

2018-04-30

Date (Creation)

2018-04-30

Citation identifier

EMODnetSeabedHabitats / GB001546

Cited responsible party

Organisation name	Individual name	Electronic mail address	Role

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

Available under the Open Government License v3.0

Use limitation

geossAttribution

Access constraints

Other restrictions

Other constraints

Contact the Cefas Data Manager ( datamanager@cefas.co.uk) for more information.

Spatial representation type

Vector

Denominator

5000

Language

English

Topic category

• Biota
• Oceans

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
OGC:WMS	https://ows.emodnet-seabedhabitats.eu/geoserver/emodnet_view_maplibrary/wms?	gb001546
OGC:WFS	https://ows.emodnet-seabedhabitats.eu/geoserver/emodnet_open_maplibrary/wfs?	gb001546
WWW:LINK-1.0-http--link	https://files.emodnet-seabedhabitats.eu/data/EMODnetSBHsurvey_GB001546.zip	EMODnet Seabed Habitats download

Hierarchy level

Dataset

Statement

Multibeam echosounder (MBES) data were collected under the Civil Hydrography Programme (CHP) in the area around this rMCZ for the purpose of updating navigation charts. The bathymetric component of these data has been used in the creation of the Defra Digital Elevation Model (DEM; Astrium, 2011). Existing MBES bathymetry data from the UK's CHP were provided to Cefas as fully processed and cleaned bathymetry data, as well as raw data files for further backscatter processing by Cefas. The bathymetry data were collected and processed in accordance with the International Hydrographic Organisation (IHO) Standards for Hydrographic Surveys - Order 1 (Special Publication 44, Edition 4). Processing of the backscatter data was undertaken by Cefas using the raw data provided. The software package QPS FM Geocoder Toolkit (FMGT) was used to produce fully compensated and corrected backscatter mosaics and these were exported as Floating Point Geotiff files for further analysis.

Ground truth samples were collected on board RV Cefas Endeavour in June 2014 (Cruise code: CEND0614; Callaway and Mason, 2014). Sampling stations were positioned within the rMCZ using a triangular lattice grid overlaid on the CHP map. The exact location of each sampling station was adjusted to coincide with notable bathymetric features. An underwater camera system was deployed at stations to collect video and still images of the seabed. A benthic grab was deployed to collect sediments and infauna samples at a subset of stations, where either the backscatter data indicated the presence of sediment, or the footage from the underwater video camera suggested a grab sample would be successful (Figure 2; Appendix 1).

Underwater imagery was acquired using a frame mounted drop camera towed at c 0.5 knots (c. 0.25 m s -1 ) across a 50 m ÔÇÿbullringÔÇÖ centred on the sampling location. A minimum tow duration of two minutes was carried out per deployment. Drop camera tows at stations which were not successfully sampled by the grab were extended to a minimum of 10 minutes. Extended duration tows were also conducted at approximately one third of ground truth sampling sites located to coincide with each of the acoustically distinct facies observed in the bathymetry and backscatter data. During each tow, still images were captured at regular one minute intervals and opportunistically if specific features of interest were encountered A four-point laser scaling device was used to provide a reference scale in the video and still images and imagery was geo referenced using a High Precision Acoustic Positioning system. Set-up and operation followed the MESH ÔÇÿRecommended Operating Guidelines (ROG) for underwater video and photographic imaging techniquesÔÇÖ (Coggan et al., 2007). Video was recorded simultaneously to a Sony GV-HD700 DV tape and a computer hard drive. A video overlay was used to provide station metadata, time and GPS position (of the vessel) in the recorded video image. Video and still images were analysed following an established protocol developed and used by Cefas (Coggan and Howell, 2005; JNCC, in prep.; see Annex 5). Grab sampling equipment comprised a mini Hamon grab (sampling area: 0.1 m2 ). On recovery, the contents of the grab were emptied into a large plastic bin and a representative sub-sample of sediment (approx. 0.5 litres) was taken for subsequent Particle Size Analysis (PSA). The remaining sample was photographed and sieved over a 1 mm mesh sieve to collect the benthic fauna. Fauna were preserved in 4% buffered formaldehyde for later processing ashore. For further detail on ground truth South of Portland rMCZ Post-survey Site Report 9 sample collection see the ÔÇÿSouth of Portland rMCZ Survey ReportÔÇÖ (Callaway and Mason, 2014).

Metadata

File identifier

2b0e56c8-f969-48e4-8109-7ecc57575804 XML

Metadata language

English

Character set

MD_CharacterSetCode_utf8

Hierarchy level

Dataset

Date stamp

2022-08-19T09:33:17.306Z

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