4f4c4942-4343-5764-6473-313631333233 English Natural Resources Wales Maes y Ffynnon Bangor LL57 2DW Wales opendata@cyfoethnaturiolcymru.gov.uk 2026-03-03T11:14:30.716Z NRW 1.0 wel British National Grid (EPSG:27700) Llyn Horse Mussel Multibeam Echosounder Survey data 2024 Llyn Horse Mussel Multibeam Echosounder Survey data 2024 To be added Pen Llŷn A’r Sarnau SAC Horse Mussel (Modiolus modiolus) Multibeam Echosounder Survey (MBES) data 2024 2024-12-17 NRW_DS161323 This data is from the 2024 Llyn Horse Mussel (Modiolus modiolus) Multibeam Echosounder Survey (MBES). The work was carried out by Binnies/Hydrofix funded by Nature Networks as part of an investigation into the decline observed at the reef. Both reefs were mapped to International Hydrographic order (IHO) 1a or higher. The data was processed and analysed to produce bathymetric surfaces; backscatter mosaics; a seabed classification, including the extents of the mussel beds; and measurements of the mussel bioherms. The results from the 2024 survey were then compared to previous datasets, provided by NRW, from 2005, 2008 and 2015, all of which were analysed and reprocessed. This data is from the 2024 Llyn Horse Mussel (Modiolus modiolus) Multibeam Echosounder Survey (MBES). The work was carried out by Binnies/Hydrofix funded by Nature Networks as part of an investigation into the decline observed at the reef. Both reefs were mapped to International Hydrographic order (IHO) 1a or higher. The data was processed and analysed to produce bathymetric surfaces; backscatter mosaics; a seabed classification, including the extents of the mussel beds; and measurements of the mussel bioherms. The results from the 2024 survey were then compared to previous datasets, provided by NRW, from 2005, 2008 and 2015, all of which were analysed and reprocessed. 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 Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Binnies LTD One City Place, Queens Road Chester CH1 3BQ info@binnies.com https://binnies.com/ Hydrofix Function performed by the responsible party Worley Court, 2 Bolesworth Rd, Tattenhall Chester CH3 9HW info@hydrofix.co.uk https://www.hydrofix.co.uk/ Habitats and biotopes GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme modiolus modiolus Pen Llyn a'r Sarnau SAC biogenic reef Special Areas of Conservation (SAC) (see also Candidate Special Areas of Conservation cSAC) horse mussel NRW Thesaurus 2025-01-08 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 on this data. NRW may release, publish or disseminate it freely. © 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 1 English biota Wales (WLS) -4.9379 -3.96 52.4548 53.0615 2024-06-12 2024-07-02 -25 -30 Willcock, J. (2024). Pen Llŷn A’r Sarnau SAC Horse Mussel (Modiolus modiolus) reef MBES survey report (2024) and time series analysis (2005-2024). NRW Evidence Report No: 851, 67pp, Natural Resources Wales Geographic Information System Unknown 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 data collected represents the highest quality data so far made available over the survey areas, with higher data density and thus better resolution than previously achieved. Post processing of all navigation data has ensured the highest levels of positional accuracy, with cm scale accuracies achieved, while the resulting data far exceeds the IHO 1a survey specifications prescribed. The data collected represents the highest quality data so far made available over the survey areas, with higher data density and thus better resolution than previously achieved. Post processing of all navigation data has ensured the highest levels of positional accuracy, with cm scale accuracies achieved, while the resulting data far exceeds the IHO 1a survey specifications prescribed.