NRW_DS115333 eng NRW_DS109834 dataset Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en pointOfContact 2026-03-03T14:43:47 MEDIN 3.1.2 wel eng utf8 Latitude and Longitude (EPSG::4326) Intertidal Monitoring of the Mawddach Estuary Sediments in Pen Llyn ar Sarnau Special Area of Conservation (SAC) 2012 Intertidal Monitoring of the Mawddach Estuary Sediments in Pen Llyn ar Sarnau Special Area of Conservation (SAC) 2012 Monitro Rhynglanwol ar waddodion aber Afon Dyfi yn ACA Pen Llyn a'r Sarnau yn 2012 2012-07-31 publication 4f4c4942-4343-5764-6473-313135333333 Pen Llyn a'r Sarnau Special Area of Conservation (SAC) is designated for five Annex 1 habitats and four subsidiary ones. 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). Pen Llyn a'r Sarnau Special Area of Conservation (SAC) is designated for five Annex 1 habitats and four subsidiary ones. 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). Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en owner Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en custodian 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 originator Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en distributor annually Habitats and biotopes theme GEMET - INSPIRE themes, version 1.0 2008-06-01 publication geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme Intertidal monitoring Pembrokeshire Marine SAC intertidal theme NRW Thesaurus 2025-01-08 publication geonetwork.thesaurus.local.theme.converted_nrw-keywords Sediment grain size parameters theme SeaDataNet Parameter Discovery Vocabulary 2024-06-19 publication geonetwork.thesaurus.external.theme.rdf+xml otherRestrictions There are no access restrictions to this data. NRW may release, publish or disseminate it freely. no limitations otherRestrictions © 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. vector eng utf8 biota NRW Geographic Identifiers Collection 2024-01-01 publication Wales (WLS) -4.27335298 -3.90245813 52.57947478 52.82531975 SeaVoX Vertical Co-ordinate Coverages 2013-02-05 creation littoral 2012-07-23 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. 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 (Survey Number MRCCW16300000044) dataset 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 publication This dataset has not been assessed for conformance to the referenced INSPIRE regulation. false Four infaunal community sampling transects were set up in 1999 which run out into the middle of the Mawddach estuary. These transects run across the sediment flats. There are two originating from the southern shore and two from the north shore and originally the sediment beyond the lower saltmarsh was sampled at 25 m intervals, to the lower water mark. In order to meet the sampling requirements of the Water Framework Directive (as well as the Habitats Directive), additional infaunal samples were required to provide sufficient sampling of sand, muddy sand and mud habitats. For this reason, some additional sampling stations were located along transects between the existing transects. At each 25 m station, the sediments were described and photographed. Once each of the three target zones were identified, a batch of 3 x 0.01 m2 core samples and a granulometry sample were collected from the middle of the zone. These cores were sieved in the field over a 0.5 mm mesh .All survey completed by professional and experienced marine field surveyors. Data quality and confidence considered moderate to high. Four infaunal community sampling transects were set up in 1999 which run out into the middle of the Mawddach estuary. These transects run across the sediment flats. There are two originating from the southern shore and two from the north shore and originally the sediment beyond the lower saltmarsh was sampled at 25 m intervals, to the lower water mark. In order to meet the sampling requirements of the Water Framework Directive (as well as the Habitats Directive), additional infaunal samples were required to provide sufficient sampling of sand, muddy sand and mud habitats. For this reason, some additional sampling stations were located along transects between the existing transects. At each 25 m station, the sediments were described and photographed. Once each of the three target zones were identified, a batch of 3 x 0.01 m2 core samples and a granulometry sample were collected from the middle of the zone. These cores were sieved in the field over a 0.5 mm mesh .All survey completed by professional and experienced marine field surveyors. Data quality and confidence considered moderate to high.