4f4c4942-4343-5764-6473-313131313833 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 2026-03-03T16:13:18.58Z NRW 1.0 wel British National Grid (EPSG::27700) Intertidal Monitoring of Muddy Gravel in Pen Llyn a'r Sarnau Special Area of Conservation (SAC) 2007 Intertidal Monitoring of Muddy Gravel in Pen Llyn a'r Sarnau Special Area of Conservation (SAC) 2007 Gwaith monitro rhynglanwol ar raean lleidiog yn ACA Pen Llyn a'r Sarnau yn 2007 2007 CCW / ASML Pen Llyn ar' Sarnau SAC Muddy gravel monitoring, Dwyryd/Glaslyn MRCCW1630000000A 2009-03-31 NRW_DS111183 The purpose of this data capture was to carry out a repeat survey of sites previously surveyed to further test and develop monitoring methodology and collect monitoring data. In fully marine conditions on the lower shore, sheltered muddy gravel habitats can be particularly species rich due to the complex nature of the substratum supporting a high diversity of infauna and epifauna. Analysis of survey records held on the Marine Nature Conservation Review (MNCR) database suggest that fully saline sheltered muddy gravel communities are scarce in their British distribution, with available descriptions lacking detail and comprehensive data. This has been attributed to the habitats being difficult to survey and monitor, due to the large quantities of coarse material which require sampling and subsequent analysis. Similarly, historical data on the distribution of muddy gravel beds appears limited. This data set includes results of sediment coring and sampling undertaken at one site in Porthmadog during intertidal monitoring of the muddy gravel in Pen Llyn a'r Sarnau Special Area of Conservation (SAC). The purpose of this data capture was to carry out a repeat survey of sites previously surveyed to further test and develop monitoring methodology and collect monitoring data. In fully marine conditions on the lower shore, sheltered muddy gravel habitats can be particularly species rich due to the complex nature of the substratum supporting a high diversity of infauna and epifauna. Analysis of survey records held on the Marine Nature Conservation Review (MNCR) database suggest that fully saline sheltered muddy gravel communities are scarce in their British distribution, with available descriptions lacking detail and comprehensive data. This has been attributed to the habitats being difficult to survey and monitor, due to the large quantities of coarse material which require sampling and subsequent analysis. Similarly, historical data on the distribution of muddy gravel beds appears limited. This data set includes results of sediment coring and sampling undertaken at one site in Porthmadog during intertidal monitoring of the muddy gravel in Pen Llyn a'r Sarnau Special Area of Conservation (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 Habitats and biotopes GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme intertidal river Glaslyn (afon Glaslyn) Special Areas of Conservation (SAC) - SAC monitoring Special Areas of Conservation (SAC) (see also Candidate Special Areas of Conservation cSAC) muddy gravel Pen Llyn a'r Sarnau SAC NRW Thesaurus 2025-01-08 geonetwork.thesaurus.local.theme.converted_nrw-keywords Sedimentary structure Habitat characterisation Zoobenthos generic abundance Zoobenthos taxonomic abundance SeaDataNet Parameter Discovery Vocabulary 2024-06-19 geonetwork.thesaurus.external.theme.rdf+xml The following data is considered OS derived data and is therefore jointly owned by NRW and the Ordnance Survey. NRW may release, publish or disseminate this data freely; providing recipients are made aware of use restrictions (See general use restrictions). no limitations © CNC/NRW and © Crown copyright 2009. All rights reserved. Natural Resources Wales, AC0000849444. Third parties seeking to re-use this data require a Licence issued by NRW. It allows re-use, reproduction and dissemination in any format or medium but only for non-commercial purposes, according to the terms and conditions of the Licence. Those seeking commercial re-use require a commercial licence available from the OS. Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. Contains Ordnance Survey Data. Ordnance Survey Licence number AC0000849444. Crown Copyright and Database Right. NRW Conditional English oceans biota Wales (WLS) -4.24086371 -4.0850534 52.84726187 52.93709632 SeaVoX Vertical Co-ordinate Coverages 2013-02-05 creation soil and sediment boundary layer 2007-08-31 2007-08-31 Intertidal monitoring of Pen Llyn a'r Sarnau SAC August 2007 Documents Unknown [A] Digital versions of the contract report: Microsoft Word document(s); and an equivalent Adobe Portable Document Format version [B] Excel Spreadsheets of data: - Dyfi Marine Recorder Spp Data 2007 V4.xls - HEBOG1730_Dyfi_ infauna_2007.xls [C] A series of MapInfo GIS layers in MapInfo Native format (Tables).Translations from the MapInfo Tables are retained in ESRI Shapefile and MapInfo Interchange formats.: [D] Marine Recorder files: MRCCW1630000000A [E] Photographs of the site, sediment characteristics, core contents and quadrats. 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 Five core samples were taken using a 0.01m2 corer. The cores were taken within a radius of approximately 5 m from the central mark; and randomly placed without reference to the surface features (with eyes closed). Each core was then sieved over a 0.5 mm mesh and the sieve contents transferred to a suitable labelled pot or plastic bag. These samples were then taken back to the field survey base and preserved in 10% formalin. A sample of the sediment was also taken from each station for granulometry analysis. The sample was usually taken from the side of one of the corer holes, to a depth of at least 5cm, and placed in a labelled plastic bag. Samples for macrofauna and granulometry analyses were given to CCW for later transfer to an analytical laboratory. The confidence in this data is high as the surveys were carried out by a team of highly experienced intertidal surveyors. Five core samples were taken using a 0.01m2 corer. The cores were taken within a radius of approximately 5 m from the central mark; and randomly placed without reference to the surface features (with eyes closed). Each core was then sieved over a 0.5 mm mesh and the sieve contents transferred to a suitable labelled pot or plastic bag. These samples were then taken back to the field survey base and preserved in 10% formalin. A sample of the sediment was also taken from each station for granulometry analysis. The sample was usually taken from the side of one of the corer holes, to a depth of at least 5cm, and placed in a labelled plastic bag. Samples for macrofauna and granulometry analyses were given to CCW for later transfer to an analytical laboratory. The confidence in this data is high as the surveys were carried out by a team of highly experienced intertidal surveyors.