Bangor University School of Ocean Sciences (SOS) Cardigan Bay Special Area of Conservation (SAC) Towed Video Seabed Surveys (2009 - 2011)
The primary aim of the survey work and reports by the School of Ocean Sciences was to assess the characteristics and status of offshore benthic habitats, and primarily whether 'stony reef' habitat was present and then to assess the effects of scallop dredging on those habitats. The secondary aim of this data capture was to improve seabed habitat mapping for Cardigan Bay and assign biotopes. Surveys of seabed in Cardigan Bay Special Area of Conservation (SAC) carried out by the School of Ocean Sciences (SOS) Bangor University in 2009, 2010 and 2011. Work included side-scan surveys (December 2009) grab sampling of sediments for particle size analysis (December 2009 and June 2010) and drop-down video and stills camera tows (all four surveys). The drop-down imagery dataset comprises: Survey 1 (December 2009): 72 tows (4743 stills); Survey 2 (June 2010): 59 tows (4720 stills); Survey 3 (December 2010): 13 tows (1364 stills); Survey 4 (April 2011): 47 tows (5347 stills). Video tows were approximately 10 minutes in length with still images taken every 10 seconds along the length of the tow. The videos and still images from the first two surveys were analysed by SOS and subsequently converted by Coastal Assessment Liaison and Monitoring (CALM) to a format suitable for entry into Marine Recorder including assignment of biotopes. The videos and still images from the last two surveys were analysed by CALM to describe habitats species and biotopes. Grab samples were taken from each site during the first two surveys but only the sediment particle size analyses data from the first survey are included in this dataset. Sidescan survey data are not included with this dataset. The four surveys described were not directly associated with any other programme and no further work is currently planned. However it is important to note that staff in the SOS are still working on the data collected during this survey and are planning to produce publications from it.
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS115275
- Alternative Title
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- 2009 SOS towed video Survey of offshore habitats in the Cardigan Bay SAC MRCCW3160000000A
- 2010 SOS (June) towed video Survey of offshore habitats in the Cardigan Bay SAC MRCCW3160000000C
- 2011 SOS towed video Survey of offshore habitats in the Cardigan Bay SAC MRCCW3160000000E
- 2010 (December) SOS towed video Survey of offshore habitats in the Cardigan Bay SAC MRCCW3160000000D
- Arolygon fideo llusg o wely'r môr (2009 - 2011) ACA Bae Ceredigion, Ysgol Gwyddorau Eigion Prifysgol Bangor (SOS)
- Metadata Language
- English
- Lineage
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Survey platform for drop-down tows and grab sampling was SOS research vessel Prince Madog. Grab sampling was carried out with a Hamond grab and sediment samples were partly processed on-board. As the main aim of the survey was to map areas of rocky reef, the on-board processing only weighed those fractions retained by 5 and 64 mm sieves. However, subsequent laboratory analysis of sub-samples provided particle size data on the finer fractions. Drop-down tows were carried out with a sledge mounted video and stills camera system (models unspecified) which was towed at a speed of approx. 0.5 knots for a period of 10 minutes. Continuous video footage was recorded on DVD and the digital stills camera took a high resolution image every 10 seconds. The field of view of the video camera covered an area of approximately 0.12m2 (width 0.41m x depth 0.30m). Each still image covered an area of 0.13m2 (0.44m x 0.30m). A manual log was kept of the position and time at the start and end of transect while the camera was on the bottom. Video and stills were analysed by marine biological surveyors to record information on habitat character, conspicuous species and their abundance. Analysis of the images from the first two surveys, by SOS staff, calculated species abundance from the number of stills in which the species was recorded and the area of seabed photographed. Analysis of the images and video from the last two surveys, by CALM staff, estimated abundance using the SACFOR abundance scale). Habitat descriptions and assignment of biotopes from the national biotope classification to each record was later carried out by CALM. Analysis included a QA process to validate and verify the recorded data. The four surveys described were not directly associated with any other programme and no further work is currently planned. However, it is important to note that staff in the SOS are still working on the data collected during this survey, and are planning to produce publications from it.
- Dataset Reference Date (Publication)
- 2011-04-09
Temporal Extent
- Begin date
- 2009-12-11
- End date
- 2011-04-09
- Topic category
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- Biota
Extent
Extent
- Geographic Extent
- SIR CEREDIGION - CEREDIGION
))
Vertical Extent
- Medin Extent Keyword
-
benthic boundary layer
Vertical Extent
- Minimum value (metres)
- 25.1m
- Maximum value (metres)
- 51.3m
- Vertical CRS
- urn:ogc:def:datum:EPSG::5100 Sea Level depth is unadjusted and does not take into account tidal height
Distribution
- Format Type and Description
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Documents
Documents
()
- Specification
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[A] Digital videos in .VOB files; still images in .JPG files. [B] Field logs of dates, start and end positions (Lat/Long) and times for tows, depths etc in Excel spreadsheets. [C] Original data collation and analyses by School of Ocean Sciences in Excel spreadsheets. [D] Full analysis data (by CALM) in Excel spreadsheets and Marine Recorder (NBN) datafile. [E] Marine Recorder Survey keys: December 2009: MRCCW3160000000A, June 2010: MRCCW3160000000C, December 2010: MRCCW3160000000D, April 2011: MRCCW3160000000E.
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Documents
Documents
()
Quality
Data quality
- Quality Scope
- Dataset
- Lineage
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Survey platform for drop-down tows and grab sampling was SOS research vessel Prince Madog. Grab sampling was carried out with a Hamond grab and sediment samples were partly processed on-board. As the main aim of the survey was to map areas of rocky reef, the on-board processing only weighed those fractions retained by 5 and 64 mm sieves. However, subsequent laboratory analysis of sub-samples provided particle size data on the finer fractions. Drop-down tows were carried out with a sledge mounted video and stills camera system (models unspecified) which was towed at a speed of approx. 0.5 knots for a period of 10 minutes. Continuous video footage was recorded on DVD and the digital stills camera took a high resolution image every 10 seconds. The field of view of the video camera covered an area of approximately 0.12m2 (width 0.41m x depth 0.30m). Each still image covered an area of 0.13m2 (0.44m x 0.30m). A manual log was kept of the position and time at the start and end of transect while the camera was on the bottom. Video and stills were analysed by marine biological surveyors to record information on habitat character, conspicuous species and their abundance. Analysis of the images from the first two surveys, by SOS staff, calculated species abundance from the number of stills in which the species was recorded and the area of seabed photographed. Analysis of the images and video from the last two surveys, by CALM staff, estimated abundance using the SACFOR abundance scale). Habitat descriptions and assignment of biotopes from the national biotope classification to each record was later carried out by CALM. Analysis included a QA process to validate and verify the recorded data. The four surveys described were not directly associated with any other programme and no further work is currently planned. However, it is important to note that staff in the SOS are still working on the data collected during this survey, and are planning to produce publications from it.
Keywords
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
- NRW Thesaurus
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- Video survey
- benthic marine habitats
- Sediment PSA
- Type
- Theme
Citation
- Date (Publication)
- 2023-12-31
Keywords
- SeaDataNet Parameter Discovery Vocabulary
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- Habitat characterisation
- Zoobenthos taxonomic abundance
- Seabed photography
- Type
- Theme
Citation
- Date (Revision)
- 2021-01-06
Spatial Reference System
Content
Content Information
NRW Profile
Custom Elements
Constraints
Constraints
Limitations on Public Access and Use
- Restriction type
- Other restrictions
Access Constraints Directive
- Limitations
- no limitations
Access Constraints Text
- Other constraints
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This dataset is wholly owned by School of Ocean Sciences, Bangor University. NRW may provide access to this dataset on request in some circumstances. However, enquirers are advised to obtain a copy from the owner/originator directly, rather than NRW. NRW may NOT publish or disseminate it in its entirety.
Use Constraints
- Use constraints type
- Other restrictions
- Other constraints
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© Bangor University 2011 NRW does NOT grant permission to third parties to re-use or disseminate this dataset. Those seeking such permission should approach the originator directly.
Metadata
Metadata
- File Identifier
- 4f4c4942-4343-5764-6473-313135323735 XML
- Metadata Language
- English
- Parent Identifier
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Natural Resources Wales (NRW) Marine Benthic Species and Habitat Collation Held in Marine Recorder
NRW_DS114501
- Resource type
- Dataset
- Metadata Date
- 2024-05-31T09:31:57.384Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
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1.0