A Survey of Native Oyster Beds (Ostrea edulis) in Wales
The native flat oyster Ostrea edulis is a UK and Welsh Biodiversity Action Plan (BAP) species, for which a UK action plan exists. Native oysters have a long history of over-exploitation in Wales and elsewhere in the UK. Oyster fisheries around Wales declined during the early 1900's due to intense exploitation, possibly combined with disease and poor recruitment. Significant oyster beds are now restricted to only a few locations. The remaining oyster population in Wales are under threat through increased fishery effort in the existing oyster fishery and from diversification of fishing activities in the fisheries. The purpose of this data capture was to gather data on the distribution and abundance of oysters in locations known to currently support native oyster beds; and, to collect samples of oysters for age analysis and to gather data on the marine biodiversity associated with oyster beds. This dataset also helps towards a further understanding of the ecology of native oysters as well as informing management decisions (part of the UK and Welsh Biodiversity Action Plan (BAP).
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS101779
- Alternative Title
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- 2002 CCW Survey of native oyster beds (Ostrea edulis) in Wales MRCCW30000000032
- Arolwg o welyau wystrys cynhenid (Ostrea edulis) yng Nghymru
- Metadata Language
- English
- Lineage
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A total of ten sites were visited between 13th and 18th September 2002. Of these ten sites, seven were located within Milford Haven, one off Porthcawl, and two sites within Swansea Bay. A differential GPS was used to ensure the positional accuracy of each site (at least 5 m). Abundance and distribution of O. edulis was recorded at each site by a pair of divers using a pre-laid transect line up to 50 m in length and a 2 m survey corridor. Each diver surveyed one side of the transect line with oyster counts taken at 10 m intervals. At each 10 m interval the total number of oysters was recorded onto slates and physical data including substrate composition was also recorded. Oysters along survey corridors were collected by a pair of divers. The oysters were placed into hessian sacks which were labelled with total number of oysters, date, site, transect number and distance along transect travelled. The samples were frozen on return to shore and couriered to the University of Wales Bangor for age analysis, see separate metadata entry 'Age and growth analysis of native oyster beds (Ostrea edulis) in Wales'. JNCC Marine Nature Conservation Review (MNCR) Phase II methodology was used to evaluate the marine biodiversity associated with native oyster beds. The divers kept a particular look out for any additional UK priority Biodiversity Action Plan species or other rarities, also, any oysters missed during the initial transect survey were collected with a note made of what distance along the transect line they were found. Still photography was undertaken at each site where visibility allowed. All Diving Operations were run in accordance with the Approved Code of Practice for Scientific and Archaeological Diving Projects and Emu Ltd's. In-house Method Statement 18 - Operating Procedures and Rules for Scientific Diving within Emu Ltd.
- Dataset Reference Date (Publication)
- 2003-04-30
Temporal Extent
- Begin date
- 2002-09-13
- End date
- 2002-09-18
- Topic category
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- Biota
Extent
Extent
- Geographic Extent
- Irish Sea
- Geographic Extent
- Swansea Bay
- Geographic Extent
- Cardigan Bay
- Geographic Extent
- St. Brides Bay
- Geographic Extent
- Wales (WLS)
))
Vertical Extent
- Medin Extent Keyword
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benthic boundary layer
Distribution
- Format Type and Description
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-
Documents
Documents
()
- Specification
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[A] Report is held in Word and PDF format. [B] Species data, oyster aging data, oyster counts and morphometric parameters are held within an xls spreadsheet. [C] Images at various sites are also held as .jpeg files. [D] Spatial data is present as tab files. [E] Species data held in Marine Recorder survey: MRCCW30000000032
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Documents
Documents
()
Quality
Data quality
- Quality Scope
- Dataset
- Lineage
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A total of ten sites were visited between 13th and 18th September 2002. Of these ten sites, seven were located within Milford Haven, one off Porthcawl, and two sites within Swansea Bay. A differential GPS was used to ensure the positional accuracy of each site (at least 5 m). Abundance and distribution of O. edulis was recorded at each site by a pair of divers using a pre-laid transect line up to 50 m in length and a 2 m survey corridor. Each diver surveyed one side of the transect line with oyster counts taken at 10 m intervals. At each 10 m interval the total number of oysters was recorded onto slates and physical data including substrate composition was also recorded. Oysters along survey corridors were collected by a pair of divers. The oysters were placed into hessian sacks which were labelled with total number of oysters, date, site, transect number and distance along transect travelled. The samples were frozen on return to shore and couriered to the University of Wales Bangor for age analysis, see separate metadata entry 'Age and growth analysis of native oyster beds (Ostrea edulis) in Wales'. JNCC Marine Nature Conservation Review (MNCR) Phase II methodology was used to evaluate the marine biodiversity associated with native oyster beds. The divers kept a particular look out for any additional UK priority Biodiversity Action Plan species or other rarities, also, any oysters missed during the initial transect survey were collected with a note made of what distance along the transect line they were found. Still photography was undertaken at each site where visibility allowed. All Diving Operations were run in accordance with the Approved Code of Practice for Scientific and Archaeological Diving Projects and Emu Ltd's. In-house Method Statement 18 - Operating Procedures and Rules for Scientific Diving within Emu Ltd.
Keywords
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
- NRW Thesaurus
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- oysters
- ostrea edulis
- distributions
- species distribution
- biotopes
- Type
- Theme
Citation
- Date (Publication)
- 2023-12-31
Keywords
- SeaDataNet Parameter Discovery Vocabulary
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- Shellfish morphology, age and physiology
- Type
- Theme
Citation
- Date (Revision)
- 2021-01-06
Spatial Reference System
Content
Content Information
NRW Profile
Custom Elements
- NRW Related Title
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A survey of native oyster beds (ostrea edulis) in Wales. CONFIDENTIAL
- NRW Related Title
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Age and growth analysis of native oyster beds (ostrea edulis) in Wales. CONFIDENTIAL
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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Part of this dataset is sensitive and restricted. The sensitive data is as follows; Ostrea edulis, Oyster bed habitat. Sensitive data must be kept confidential; general release, is not permitted due to risk of harm to the environment or third parties. Sensitive data may only be released under a CCW Restricted Release Licence. Requests should be referred to CCW's Access to Information Officer. Data may be released freely if the sensitive records are removed in advance, or shown only at a coarser scale.
Use Constraints
- Use constraints type
- Other restrictions
- Other constraints
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© CNC/NRW NRW does NOT grant permission to third parties to re-use or disseminate this dataset.
Metadata
Metadata
- File Identifier
- 4f4c4942-4343-5764-6473-313031373739 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
- 2024-05-31T09:41:19.935Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
-
1.0