4f4c4942-4343-5764-6473-313135303635 English NRW_DS109834 Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en 2026-10-19T10:22:41.413Z NRW 1.0 wel utf8 British National Grid (EPSG::27700) Intertidal Monitoring of Muddy Gravel, Sediments and Rocky Shore in Pen Llyn a'r Sarnau Special Area of Conservation (SAC) 2008 Intertidal Monitoring of Muddy Gravel, Sediments and Rocky Shore in Pen Llyn a'r Sarnau Special Area of Conservation (SAC) 2008 Arolwg rhynglanw o Raean Lleidiog, Gwaddod a Glan Mor Creigiog y ACA Pen Llyn a'r Sarnau 2008 2008 CCW / ASML Pen Llyn a'r Sarnau SAC Dwyryd/Glaslyn (MRCCW1630000000E) 2010-10-31 NRW_DS115065 http://naturalresources.wales/ Pen Llyn a'r Sarnau Special Area of Conservation (SAC) is designated for five Annex 1 habitats and four subsidiary ones. The major features of intertidal interest are Estuaries and their constituent mudflats, sandflats and reefs, Large shallow inlets and bays with intertidal Zostera beds, populations of the shingle dwelling amphipod Pectenogammarus, piddocks in clay and lower shore boulder communities and Reefs, particularly biogenic reefs of Sabellaria alveolata. Specific areas of interest for are the intertidal sediments and rocky areas in the Glaslyn and Dwyryd Estuaries. There were two purposes for this data capture. The first was related to sediments. Sediment data was collected to test monitoring methodology, establish sites for long term monitoring and collect baseline and reference data. The second was related to the Data collected on the rocky shore to establish sand levels at key rocky areas - Port Meirion, Ynys Gifftan and Cei Ballast. Pen Llyn a'r Sarnau Special Area of Conservation (SAC) is designated for five Annex 1 habitats and four subsidiary ones. The major features of intertidal interest are Estuaries and their constituent mudflats, sandflats and reefs, Large shallow inlets and bays with intertidal Zostera beds, populations of the shingle dwelling amphipod Pectenogammarus, piddocks in clay and lower shore boulder communities and Reefs, particularly biogenic reefs of Sabellaria alveolata. Specific areas of interest for are the intertidal sediments and rocky areas in the Glaslyn and Dwyryd Estuaries. There were two purposes for this data capture. The first was related to sediments. Sediment data was collected to test monitoring methodology, establish sites for long term monitoring and collect baseline and reference data. The second was related to the Data collected on the rocky shore to establish sand levels at key rocky areas - Port Meirion, Ynys Gifftan and Cei Ballast. 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 Countryside Council for Wales (CCW). Marine and Freshwater Ecosystems Group Maes y Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@ccw.gov.uk http://www.ccw.gov.uk Aquatic Survey and Monitoring Ltd (ASML) Whitfield Brow, Bollihope, Frosterley, Weardale, Co. Durham, DL13 2SZ, England tom@aquatic-environments.co.uk http://www.marineseen.com/aquatic_survey_and_monitoring.htm 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 Marine Recorder Pen Llyn a'r Sarnau SAC Mudflats and sandflats NRW Thesaurus 2026-08-27 geonetwork.thesaurus.local.theme.converted_nrw-keywords Habitat characterisation SeaDataNet Parameter Discovery Vocabulary 2024-06-19 geonetwork.thesaurus.external.theme.rdf+xml There are no access restrictions to this data. NRW may release, publish or disseminate it freely. no limitations © CNC/NRW Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and NRW's copyright. It is the recipient's responsibility to ensure the data is fit for the intended purpose. Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. Open Government Licence 400 English biota SeaVoX Vertical Co-ordinate Coverages 2021-01-06 benthic boundary layer GWYNEDD - GWYNEDD -4.17054843 -4.03716729 52.87783429 52.87783429 2008-10-18 2008-10-20 Across Wales intertidal SAC monitoring Pen Llyn a'r Sarnau SAC: August 2008 Database Marine Recorder Online - Version 2.09.02 Marine Recorder 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 In situ recording of sediment characteristics were undertaken across the whole area of the sediment flats. This data capture included epibiota, infauna and granulometry sampling. A collection of samples from ten stations were then analysed in the laboratory for infauna and sediment granulometry. Quadrat recording on three rocky shores was undertaken. One muddy gravel habitat site was visited at Carreg y Defaid but the tide failed to expose enough of the bank to allow a detailed survey. A species list was generated and some specimens were collected for identification. Data quality and confidence was considered high, as all surveys were completed by professional and experienced marine field surveyors. The methodology for the in situ grid stations was an adaptation of Phase I survey techniques developed for an earlier survey of the Mawddach Estuary (Wyn and Cooke, 2001). Monitoring was also previously carried out in 2007. All survey completed by professional and experienced marine field surveyors. Data quality and confidence considered high. In situ recording of sediment characteristics were undertaken across the whole area of the sediment flats. This data capture included epibiota, infauna and granulometry sampling. A collection of samples from ten stations were then analysed in the laboratory for infauna and sediment granulometry. Quadrat recording on three rocky shores was undertaken. One muddy gravel habitat site was visited at Carreg y Defaid but the tide failed to expose enough of the bank to allow a detailed survey. A species list was generated and some specimens were collected for identification. Data quality and confidence was considered high, as all surveys were completed by professional and experienced marine field surveyors. The methodology for the in situ grid stations was an adaptation of Phase I survey techniques developed for an earlier survey of the Mawddach Estuary (Wyn and Cooke, 2001). Monitoring was also previously carried out in 2007. All survey completed by professional and experienced marine field surveyors. Data quality and confidence considered high.