4f4c4942-4343-5764-6473-313131313834 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 2026-10-19T09:42:50.151Z NRW 1.0 wel utf8 British National Grid (EPSG::27700) Intertidal Monitoring of the Dyfi Estuary in Pen Llyn a'r Sarnau Special Area of Conservation (SAC) 2007 Intertidal Monitoring of the Dyfi Estuary in Pen Llyn a'r Sarnau Special Area of Conservation (SAC) 2007 Gwaith monitro rhynglanwol ar aber Afon Dyfi yn ACA Pen Llyn a'r Sarnau yn 2007 2007 CCW/ASML Pen Llyn a'r Sarnau SAC Dyfi Estuary monitoring (MRCCW16300000009) 2009-03-01 NRW_DS111184 http://naturalresources.wales/ The purpose of this data capture was to establish sites for long-term monitoring and collect baseline and reference data using appropriate methods. Pen Llyn a'r Sarnau Special Area of Conservation is designated for five Annex 1 habitats and four subsidiary. Pen Llyn a'r Sarnau has representative examples of bar-built estuaries in north-west Wales, and includes the Glaslyn/Dwyryd, Mawddach and Dyfi estuaries. The purpose of this data capture was to establish sites for long-term monitoring and collect baseline and reference data using appropriate methods. Pen Llyn a'r Sarnau Special Area of Conservation is designated for five Annex 1 habitats and four subsidiary. Pen Llyn a'r Sarnau has representative examples of bar-built estuaries in north-west Wales, and includes the Glaslyn/Dwyryd, Mawddach and Dyfi estuaries. 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 Pen Llyn a'r Sarnau SAC Marine Recorder 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 English biota SeaVoX Vertical Co-ordinate Coverages 2021-01-06 benthic boundary layer Wales (WLS) -4.50689228 -3.75150601 52.37767239 52.66290714 2007-08-27 2007-08-31 Intertidal monitoring of Pen Llyn a'r Sarnau SAC August 2007 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 There were three parts to the work: - In-situ recording of sediment characteristics (including epibiota, infauna and granulometry) at a grid of 106 stations across the whole area of the sediment flats; - Collection of samples from eleven stations for laboratory analysis of infauna; - Sediment granulometry and surveys including quadrat recording on three rocky shores. Modified version of the phase 1 style survey methodology was used. The Grid Maker tool in MapInfo was used to create a grid of 96 stations overlaying existing maps of the Dyfi sediment flats. A single 0.01m2 core sample was taken at each station. This was sieved in a nearby pool and all visible animals were identified and counted. The unrecognisable animals were collected for later inspection under a microscope. Records of conspicuous species and surface sediment features were made from each station within a circle of 1m radius around the core sample position. In addition to the in-situ recording, core samples were also taken from 11 sites for standard laboratory analysis of macro-infauna and granulometry. Three representative sites along the northern shore were selected for rocky shore surveys. At each, a transect route running down to the shore was divided into zones. The percentage cover of the major species in each zone was recorded, with the presence noted of all other species found. One zone was selected on each shore for sampling with 5 gridded quadrats (0.25 x 0.25 m), with all species present in each quadrat recorded either as percentage cover or as counts. Photographs were taken of each quadrat and each shore zone. Phase 1 surveys of intertidal habitats in the SAC were carried out between 1999 and 2003 (Brazier et al. 2007), providing detailed mapping of the intertidal biotopes with some information on characterizing species. Confidence in data is high as surveys were carried out by a team of highly experienced intertidal surveyors. There were three parts to the work: - In-situ recording of sediment characteristics (including epibiota, infauna and granulometry) at a grid of 106 stations across the whole area of the sediment flats; - Collection of samples from eleven stations for laboratory analysis of infauna; - Sediment granulometry and surveys including quadrat recording on three rocky shores. Modified version of the phase 1 style survey methodology was used. The Grid Maker tool in MapInfo was used to create a grid of 96 stations overlaying existing maps of the Dyfi sediment flats. A single 0.01m2 core sample was taken at each station. This was sieved in a nearby pool and all visible animals were identified and counted. The unrecognisable animals were collected for later inspection under a microscope. Records of conspicuous species and surface sediment features were made from each station within a circle of 1m radius around the core sample position. In addition to the in-situ recording, core samples were also taken from 11 sites for standard laboratory analysis of macro-infauna and granulometry. Three representative sites along the northern shore were selected for rocky shore surveys. At each, a transect route running down to the shore was divided into zones. The percentage cover of the major species in each zone was recorded, with the presence noted of all other species found. One zone was selected on each shore for sampling with 5 gridded quadrats (0.25 x 0.25 m), with all species present in each quadrat recorded either as percentage cover or as counts. Photographs were taken of each quadrat and each shore zone. Phase 1 surveys of intertidal habitats in the SAC were carried out between 1999 and 2003 (Brazier et al. 2007), providing detailed mapping of the intertidal biotopes with some information on characterizing species. Confidence in data is high as surveys were carried out by a team of highly experienced intertidal surveyors.