| Title of dataset | 2013, Envision Mapping, Dogger Bank, Creyke Beck Project Habitat Mapping |
| Narrative summary of dataset | Envision have undertaken a biological interpretation of the geophysical data from Tranche A and Creyke Beck Export Cable Route. The strategy for this interpretation was to integrate sample records and the geophysical remotely sensed images to produce distribution maps. This follows the strategy that has been established within the EU through the MESH program.
The primary purpose of analysis was to derive a limited range of habitat classes suitable for ground truthing the acoustic data, which were adopted as the mapping units. The requirements for successful ground truthing are not exactly the same as describing diversity. There has been more emphasis on commonality and potential for overlap between the mapping units. The analyses identified a small number of robust classes from the infauna defined by their predominant species and those that contributed most to the classes distinctiveness. Information on epifauna and gravel/cobble were incorporated to derive a single ground truth dataset Suitable ground truth data assigned to habitat classes is vital for integrated analysis and this necessitated Envision undertaking the analysis of the sample records to derive a locally relevant list of habitat classes. The analyses identified a small number of robust classes from the infauna defined by their predominant species and those that contributed most to the classes distinctiveness. Information on epifauna and gravel/cobble were incorporated to derive a single ground truth dataset The faunal composition of these groups were then matched to the Marine Habitat Classification for Britain and Ireland (v04.05) and a suite of possible biotopes assigned to the ground truth data.
The geophysical data required processing and transformation to render the images suitable for integrated analysis. The analyses have been reported and the full list of habitat classes described. The interpretation of the geophysical data through integrated analysis with the ground truth data has been reported and the habitat class distribution map has been presented. Surficial sediments were identified from the still images and classified. These data have been used to ground truth the geophysical images and a map has been generated. The distribution of the habitats is discussed. The biota is typical of moderately exposed (moderately disturbed) gravelly sandy sediments in the North Sea. Although all the habitats can be considered components of Annex 1 Subtidal Sandbanks, there are no biotopes of particular sensitivity and, although Sabellaria spinulosa was found, the densities of individuals in samples was never very high and it is unlikely that any sample sites could be classified as biogenic reef.
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| Summary of processing methodology | Geophysical data was collected using Single beam, multibeam, side scan sonar, pinger, sparker and magnetometer data were collected by Gardline Geosurvey Limited across Tranche B over two periods; June to October 2011 and March to May 2012, using two vessels MV L’Espoir and the MV Tridens1 and Titan Environmental Surveys Ltd acquired data for the nearshore survey cable
corridors from landfall to 10.5km offshore.
The benthic sublittoral survey comprised sampling via drop down video/camera, mini Hamon grab and Day grab. This drop camera data was used to ground truth collected geophysical data.
Trawl data was collected using a commercial scraper otter trawl with a 130mm mesh cod end and a 2m scientific beam trawl with a 5mm cod end was also used was used for sampling at all sampling stations.
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| Start date | 2010-06-01 |
| End date | 2013-10-30 |
| Frequency of observations | year to sub-decade |