4f4c4942-4343-5764-6473-313135333332 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 2026-03-03T12:40:20.522Z NRW 1.0 wel Latitude and Longitude (EPSG::4326) Intertidal Monitoring of Sabellaria alveolata Reefs in Pen Llyn a'r Sarnau Special Area of Conservation (SAC) 2012 Intertidal Monitoring of Sabellaria alveolata Reefs in Pen Llyn a'r Sarnau Special Area of Conservation (SAC) 2012 Monitro Rhynglanwol ar riffiau Sabellaria alveolata yn ACA Pen Llyn a'r Sarnau yn 2012 2012-07-31 NRW_DS115332 Pen Llyn a'r Sarnau Special Area of Conservation (SAC) is designated for five Annex 1 habitats and four subsidiary ones, listed in Table 1. Of these, 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; are the main habitats of interest within the intertidal areas of the SAC. Conservation objectives for these habitats are given in the Regulation 33 advice for the SAC (CCW 2009). The purpose of this data capture was to continue monitoring the intertidal area within the SAC. Pen Llyn a'r Sarnau Special Area of Conservation (SAC) is designated for five Annex 1 habitats and four subsidiary ones, listed in Table 1. Of these, 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; are the main habitats of interest within the intertidal areas of the SAC. Conservation objectives for these habitats are given in the Regulation 33 advice for the SAC (CCW 2009). The purpose of this data capture was to continue monitoring the intertidal area within the SAC. 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 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 intertidal monitoring programmes Infauna Pembrokeshire Marine SAC NRW Thesaurus 2025-01-08 geonetwork.thesaurus.local.theme.converted_nrw-keywords Zoobenthos taxonomic abundance Zoobenthos generic abundance 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 2012. 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. Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. Open Government Licence English biota Wales (WLS) -4.82085408 -3.77884202 52.24343537 52.99686039 SeaVoX Vertical Co-ordinate Coverages 2013-02-05 creation littoral 2012-07-24 2012-07-24 Mercer, T.S. 2013. Intertidal SAC monitoring, Pen Llyn a’r Sarnau SAC July 2012. CCW Marine Monitoring Report No: 102, pp 68 + x, Aquatic Survey & Monitoring Ltd. Bollihope, Co. Durham. Intertidal SAC monitoring Pen Llyn a'r Sarnau SAC July 2012 Documents [A] Digital versions of the contract report: Microsoft Word document(s); and an equivalent Adobe Portable Document Format version. [B] Excel spreadsheets with species data from quadrat surveys. [C] Photographs of the quadrats. [D] Marine Recorder file MRCCW16300000038. 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 The Llandanwg and West Afon Dwyfor Sabellaria reef transects were re-surveyed in 2012, having been surveyed by ASML in 2009 and 2010. Existing 2010 maps of Sabellaria reef in these areas were used to orientate the work area in 2012. At both Llandanwg and West Afon Dwyfor the survey task was to re-survey the areas surveyed by quadrat in 2009 and 2010. The Sabellaria reef in the vicinity of the quadrat sites was also mapped from the upper limit of Sabellaria on the shore, to the lower limit of access on the shore, as dictated by the height of the low tide. The mapped areas were not as large as the 2010 areas, as the tides were not as workable in 2012. On the shore, the GPS units were used by the survey teams to navigate to the correct, central position for each quadratting area within the 'quadrat zone' described in 2009, within the Sabellaria reef. At each quadrat station, surveyors established an origin at the centre of an imaginary 20 m x 20 m grid (numbers vs letters) i.e. at location 10 'm' (= x,y) and then the surveyors proceeded to survey the initial 5 random quadrats in detail. Estimates were made of the percentage cover of standing water, total Sabellaria, live Sabellaria and a small selection of key species/taxa. Other typical fauna and flora (listed on the proforma) were then searched for and recorded. No estimation of abundance was required for these species (to speed up the recording), but rapid estimates of algal cover and other major cover organisms such as Mytilus edulis were made. The Llandanwg and West Afon Dwyfor Sabellaria reef transects were re-surveyed in 2012, having been surveyed by ASML in 2009 and 2010. Existing 2010 maps of Sabellaria reef in these areas were used to orientate the work area in 2012. At both Llandanwg and West Afon Dwyfor the survey task was to re-survey the areas surveyed by quadrat in 2009 and 2010. The Sabellaria reef in the vicinity of the quadrat sites was also mapped from the upper limit of Sabellaria on the shore, to the lower limit of access on the shore, as dictated by the height of the low tide. The mapped areas were not as large as the 2010 areas, as the tides were not as workable in 2012. On the shore, the GPS units were used by the survey teams to navigate to the correct, central position for each quadratting area within the 'quadrat zone' described in 2009, within the Sabellaria reef. At each quadrat station, surveyors established an origin at the centre of an imaginary 20 m x 20 m grid (numbers vs letters) i.e. at location 10 'm' (= x,y) and then the surveyors proceeded to survey the initial 5 random quadrats in detail. Estimates were made of the percentage cover of standing water, total Sabellaria, live Sabellaria and a small selection of key species/taxa. Other typical fauna and flora (listed on the proforma) were then searched for and recorded. No estimation of abundance was required for these species (to speed up the recording), but rapid estimates of algal cover and other major cover organisms such as Mytilus edulis were made.