Acoustic Monitoring of the Extent of the North Llyn Modiolus Reef
Biogenic horse mussel (Modiolus Modiolus) reef is an important feature of the Pen Llyn a'r Sarnau Special Area of Conservation (SAC). The reef has high biodiversity and is vulnerable to anthropogenic activities, such as benthic fishing. The mussel reef forms an undulating surface that is significantly different to the surrounding seabed and therefore acoustic monitoring methods can be used to monitor changes in extent and identity areas of potential damage. Work is carried out on the north Llyn horse mussel reef in Pen Llyn a'r Sarnau jointly by Countryside Council for Wales (CCW) and University of Wales Bangor. The purpose of this data capture was to: - Measure extent and temporal changes within the of the Modiolus reef in the Pen Llyn a'r Sarnau SAC. - Investigate the health of the reef and for signs of anthropogenic activity within the area. An area approximately 10km by 6km, adjacent to the Pen Llyn coast, south-west of Porth Dinllaen, approximately 1.5km off shore was surveyed. All data is processed to reduce errors (e.g. positional corrections). Acoustic data is subject to ground-truthing using drop down videos captured as part of a separate project. As of April 1st, 2013 data is held and managed by Natural Resources Wales (NRW).
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS109891
- Alternative Title
-
- 1999 CCW Modiolus monitoring trial survey off North Pen LLyn
- Gwaith monitro acwstig ar y riff Modiolus yng Ngogledd Llyn
- Side-scan sonar monitoring of the North Llyn Modiolus reef
- Metadata Language
- English
- Lineage
-
Side scan-sonar data is captured from either the CCW research vessel (R.V. Pedryn) or the University research vessel (R.V. Price Madog) using a CMAX CM800 sidescan sonar. Multibeam has been captured from the University research vessel (R.V. Prince Madog) in 2008 using a Kongsberg EM 3002 Dual Head multibeam echo sounder. The reef and surrounding area was also multibeamed as part of the HABMAP project in 2005 on board the Irish Marine Institute's 'Celtic Voyager' using a simrad EM1002 95KHz multibeam Echosounder. Concurrently, a sub-bottom profiling system, using a broadband high-resolution 'boomer' was also used in the same area. All data is processed and incorporated into MapInfo GIS. Analysis of the data is written up as unpublished MSc projects at the University of Wales Bangor. Project is carried out in conjunction with the Across Wales drop-down video project. Additional projects have been carried out to study the anthropogenic effects discovered at the site.
- Additional Information
-
Please see CCW Marine Monitoring Report no.50. 01/07/1998 side-scan sonar monitoring trial . Data is also available online at http://www.ukdmos.org/v_ukdmos_edios/result.asp
- Dataset Reference Date (Publication)
- 2013-04-01
Temporal Extent
- Begin date
- 1998-07-07
- End date
- 2013-04-01
- Topic category
-
- Imagery base maps earth cover
Extent
Extent
- Geographic Extent
- Irish Sea
- Geographic Extent
- Cardigan Bay
- Geographic Extent
- Tremadog Bay
- Geographic Extent
- GWYNEDD - GWYNEDD
))
Vertical Extent
- Medin Extent Keyword
-
benthic boundary layer
Vertical Extent
- Minimum value (metres)
- -25
- Maximum value (metres)
- -45
- Vertical CRS
Distribution
- Format Type and Description
-
-
Geographic Information System
Geographic Information System
()
- Specification
-
[A] All raster images held as tif files. [B] Extent of the Modiolus reef held as MapInfo file.
-
Geographic Information System
Geographic Information System
()
Quality
Data quality
- Quality Scope
- Dataset
- Lineage
-
Side scan-sonar data is captured from either the CCW research vessel (R.V. Pedryn) or the University research vessel (R.V. Price Madog) using a CMAX CM800 sidescan sonar. Multibeam has been captured from the University research vessel (R.V. Prince Madog) in 2008 using a Kongsberg EM 3002 Dual Head multibeam echo sounder. The reef and surrounding area was also multibeamed as part of the HABMAP project in 2005 on board the Irish Marine Institute's 'Celtic Voyager' using a simrad EM1002 95KHz multibeam Echosounder. Concurrently, a sub-bottom profiling system, using a broadband high-resolution 'boomer' was also used in the same area. All data is processed and incorporated into MapInfo GIS. Analysis of the data is written up as unpublished MSc projects at the University of Wales Bangor. Project is carried out in conjunction with the Across Wales drop-down video project. Additional projects have been carried out to study the anthropogenic effects discovered at the site.
Keywords
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
- NRW Thesaurus
-
- sidescan sonar
- acoustic observation (acoustic monitoring)
- modiolus modiolus
- horse mussel
- Special Area of Conservation Monitoring
- biogenic reef
- Pen Llyn a'r Sarnau cSAC
- multibeam
- Type
- Theme
Citation
- Date (Publication)
- 2023-12-31
Keywords
- SeaDataNet Parameter Discovery Vocabulary
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- Side-scan sonar
- Shellfish abundance and biomass in water bodies
- Type
- Theme
Citation
- Date (Revision)
- 2021-01-06
Spatial Reference System
Content
Content Information
NRW Profile
Custom Elements
- NRW Related Title
-
The establishment of a programme of surveillance and monitoring for judging the condition of the features of Pen Llyn a'r Sarnau cSAC : 1. Progress to March 2001
- NRW Related Title
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Review of sidescan sonar results from North Llyn
Constraints
Constraints
Limitations on Public Access and Use
- Restriction type
- Other restrictions
Access Constraints Directive
- Limitations
- no limitations
Access Constraints Text
- Other constraints
-
This data is jointly owned by NRW and the University of Wales, Bangor. There are no access restrictions to this data. NRW may release, publish or disseminate it freely.
Use Constraints
- Use constraints type
- Other restrictions
- Other constraints
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© CNC/NRW and Bangor University 2013 There are no use restrictions on this data. Recipients may re-use, reproduce, disseminate this data free of charge in any format or medium, provided they do so accurately, acknowledging both the source and the copyright of NRW / Bangor University and do not use it in a misleading context. It is the recipient's responsibility to ensure the data is fit for the intended purpose, that dissemination or publishing does not result in duplication and that it is fairly interpreted. Advice on interpretation should be sought where required. To avoid re-using old data, users should periodically obtain the latest version from the original source.
Metadata
Metadata
- File Identifier
- 4f4c4942-4343-5764-6473-313039383931 XML
- Metadata Language
- English
- Parent Identifier
-
Multibeam Acoustic Data Index
NRW_DS121633
- Resource type
- Dataset
- Metadata Date
- 2024-05-31T09:31:45.519Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
-
1.0