A Survey of Native Oyster Beds (Ostrea edulis) in Wales
Arolwg o welyau wystrys cynhenid (Ostrea edulis) yng Nghymru

  • English
  • wel
  • All

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

Dynodydd
Identifier
NRW_DS101779
Teitl Amgen
Alternative Title
  • 2002 CCW Survey of native oyster beds (Ostrea edulis) in Wales (MRCCW30000000032)
Laith Metadata
Metadata Language
English
Lineage

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.
Dyddiad cyfeirnod y set ddata (Cyhoeddiad)
Dataset Reference Date (Publication)
2003-04-30

Temporal Extent

Begin date
2002-09-13
End date
2002-09-18
 
Categori pwnc
Topic category
  • Biota
    Biota
Perchennog
Owner
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Cychwynnwr
Originator
  Emu Limited -
Head Office, 1 Mill Court, Durley, Southampton, SO32 2EJ, England
http://www.emulimited.com/
 

Extent

Extent

Hyd
Geographic Extent
Irish Sea
Hyd
Geographic Extent
Swansea Bay
Hyd
Geographic Extent
Cardigan Bay
Hyd
Geographic Extent
St. Brides Bay
Hyd
Geographic Extent
Wales (WLS)
N
W
E
S
Map representing the geographic extent of the dataset


 

Vertical Extent

Medin Extent Keyword

benthic boundary layer
 
 

Distribution

Dosbarthiad
Distribution

Fformat - Math a Disgrifiad
Format Type and Description
  • Documents ( Unknown )

    Specification

    Report is held in Word and PDF format.

  • Delimited ( Unknown )

    Specification

    Species data, oyster aging data, oyster counts and morphometric parameters are held within an xls spreadsheet.

  • Database ( Marine Recorder Online - Version 2.09.02 )

    Specification

    Marine Recorder

  • Image ( Unknown )

    Specification

    Images at various sites are also held as .jpeg files.

  • Geographic Information System ( Unknown )

    Specification

    Spatial data is present as tab files.

 

Quality

Ansawdd Data
Data quality

Cwmpas Ansawdd
Quality Scope
Dataset
Dataset
Cydymffurfiad
Conformity
Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services
Explanation

This dataset has not been assessed for conformance to the referenced INSPIRE regulation.
Degree
false
Lineage

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

Allweddair
Keywords

GEMET - INSPIRE themes, version 1.0
Math
Type
Theme
Theme

Dyfyniad
Citation

Dyddiad (Cyhoeddiad)
Date (Publication)
2008-06-01
Code
geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme

Allweddair
Keywords

NRW Thesaurus
  • ostrea edulis
  • species distribution
  • distributions
  • biotopes
  • oysters
  • Marine Recorder
Math
Type
Theme
Theme

Dyfyniad
Citation

Dyddiad (Cyhoeddiad)
Date (Publication)
2026-10-19
Code
geonetwork.thesaurus.local.theme.converted_nrw-keywords

Allweddair
Keywords

SeaDataNet Parameter Discovery Vocabulary
Math
Type
Theme
Theme

Dyfyniad
Citation

Dyddiad (Cyhoeddiad)
Date (Publication)
2024-06-19
Code
geonetwork.thesaurus.external.theme.rdf+xml
 

Spatial Reference System

Code
British National Grid (EPSG::27700)
 

Content

Gwybodaeth Cynnwys
Content Information

Proffil CNC
NRW Profile

Elfennau CNC
Custom Elements

NRW Related Title

A survey of native oyster beds (ostrea edulis) in Wales. CONFIDENTIAL
NRW Related Title

Age and growth analysis of native oyster beds (ostrea edulis) in Wales. CONFIDENTIAL
 

Constraints

Constraints

Limitations on Public Access and Use

Math o Gyfyngiad
Restriction type
Other restrictions
Other restrictions
 

Access Constraints Directive

Limitations
no limitations
 

Access Constraints Text

Other constraints

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

Cyfyngiadau Defnyddio
Use constraints type
Other restrictions
Other restrictions
Other constraints

© CNC/NRW. NRW does NOT grant permission to third parties to re-use or disseminate this dataset.
 

Attribution Statement

Other constraints

Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved.
 

Licence

Other constraints
Not Licenced for Re-use
 
 
 

Metadata

Metadata

Dynodydd Ffeil
File Identifier
4f4c4942-4343-5764-6473-313031373739 XML
Laith Metadata
Metadata Language
English
Parent Identifier
Natural Resources Wales (NRW) Marine Benthic Species and Habitat Collation Held in Marine Recorder

NRW_DS114501
Math o adnodd
Resource type
Dataset
Dataset
Dyddiad Metadata
Metadata Date
2026-10-26T15:53:18.722Z
Enw Safonol Metadata
Metadata Standard Name
NRW
Fersiwn Metadata
Metadata Standard Version

1.0

Pwynt Cyswllt
pointOfContact
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
 
 

Publishing Body

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