Review of Side-Scan Sonar Results from North Llyn Modiolus Reef
An emergency review of side-scan sonar data collected by Countryside Council for Wales (CCW) in 2007 was required as the images showed marks that were potentially derived from trawling gear. The area was approximately 10 km by 6 km and approximately 1.5 km offshore, within the Pen Llyn a'r sarnau Special Area of Conservation (SAC) and is also protected under Sea Fisheries byelaws that prevent the use of trawls and dredges for the harvesting of molluscan shellfish, except as authorised by the local sea fisheries committee.
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS109893
- Alternative Title
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- Adolygiad o ganlyniadau gwaith monitro sonar yng Ngogledd Llyn
- Metadata Language
- English
- Lineage
-
Side-scan images were collected by CCW as part of their annual monitoring of the reef. In addition to sides-scan sonar images, 3 dives were conducted in the area. Digital high definition video footage from the dives was edited and slowed so they could be examined for evidence of disturbance. Maps of sediment types and waved and tidally induced bed-sheer stress for the locality were provided by the HABMAP project. This project is based on annual side-scan sonar data collected by CCW as part of ongoing monitoring on the site. Data for 2007 identified anthropogenic activities on the site that required further study.
- Additional Information
-
For further information about the methodology used for acoustic monitoring, please refer to metadata entry \Acoustic Monitoring of the North Llyn Modiolus reef\". "
- Dataset Reference Date (Publication)
- 2007-09-30
Temporal Extent
- Begin date
- 2007-05-24
- End date
- 2009-03-31
- Topic category
-
- Oceans
Extent
Extent
- 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
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-
Image
Image
()
- Specification
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[A] All raster images held as tif files. [B] Video footage held on mini DV tapes.
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Image
Image
()
Quality
Data quality
- Quality Scope
- Dataset
- Lineage
-
Side-scan images were collected by CCW as part of their annual monitoring of the reef. In addition to sides-scan sonar images, 3 dives were conducted in the area. Digital high definition video footage from the dives was edited and slowed so they could be examined for evidence of disturbance. Maps of sediment types and waved and tidally induced bed-sheer stress for the locality were provided by the HABMAP project. This project is based on annual side-scan sonar data collected by CCW as part of ongoing monitoring on the site. Data for 2007 identified anthropogenic activities on the site that required further study.
Keywords
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
- NRW Thesaurus
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- sidescan sonar
- acoustic observation (acoustic monitoring)
- modiolus modiolus
- horse mussel
- Special Area of Conservation Monitoring
- biogenic reef
- Pen Llyn a'r Sarnau cSAC
- dredging
- disturbance
- Type
- Theme
Citation
- Date (Publication)
- 2023-12-31
Keywords
- SeaDataNet Parameter Discovery Vocabulary
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- Side-scan sonar
- Habitat extent
- Habitat characterisation
- Type
- Theme
Citation
- Date (Revision)
- 2021-01-06
Spatial Reference System
Content
Content Information
NRW Profile
Custom Elements
- NRW Related Title
-
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
-
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 2007 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 NRW's copyright, 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
- 4f4c4942-4343-5764-6473-313039383933 XML
- Metadata Language
- English
- Parent Identifier
-
Acoustic Monitoring of the Extent of the North Llyn Modiolus Reef
NRW_DS109891
- Resource type
- Dataset
- Metadata Date
- 2024-05-31T09:23:31.945Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
-
1.0