4f4c4942-4343-5764-6473-313031373739 English NRW_DS114501 Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en 2026-03-03T15:45:03.489Z NRW 1.0 wel British National Grid (EPSG::27700) A Survey of Native Oyster Beds (Ostrea edulis) in Wales A Survey of Native Oyster Beds (Ostrea edulis) in Wales 2002 CCW Survey of native oyster beds (Ostrea edulis) in Wales MRCCW30000000032 Arolwg o welyau wystrys cynhenid (Ostrea edulis) yng Nghymru 2003-04-30 NRW_DS101779 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). 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). Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Emu Limited Head Office, 1 Mill Court, Durley, Southampton, SO32 2EJ, England mail@emulimited.com http://www.emulimited.com/ Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Species distribution GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme distributions biotopes oysters ostrea edulis species distribution NRW Thesaurus 2025-01-08 geonetwork.thesaurus.local.theme.converted_nrw-keywords Shellfish morphology, age and physiology SeaDataNet Parameter Discovery Vocabulary 2024-06-19 geonetwork.thesaurus.external.theme.rdf+xml 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. no limitations © CNC/NRW NRW does NOT grant permission to third parties to re-use or disseminate this dataset. English biota SeaVoX Vertical Co-ordinate Coverages 2021-01-06 benthic boundary layer Irish Sea Swansea Bay Cardigan Bay St. Brides Bay Wales (WLS) -4.51377693 -2.73779093 51.09492187 51.71466995 2002-09-13 2002-09-18 A survey of native oyster beds (ostrea edulis) in Wales. CONFIDENTIAL Age and growth analysis of native oyster beds (ostrea edulis) in Wales. CONFIDENTIAL Documents [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 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 2010-12-08 This dataset has not been assessed for conformance to the referenced INSPIRE regulation. false 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. 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.