4f4c4942-4343-5764-6473-313235333930 English Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en 2026-03-03T14:33:52.384Z NRW 1.0 wel NONE Holyhead Harbour Carpet Sea Squirt Survey Data November 2020 Holyhead Harbour Carpet Sea Squirt Survey Data November 2020 Holyhead Harbour dive survey data mapping the distribution of the non-native species Carpet sea squirt, Didemnum vexillum. 2022-11-09 NRW_DS125390 This is the raw data from a dive survey of Holyhead harbour in November 2020, which focussed on mapping the distribution of the invasive non-native species Carpet seasquirt, Didemnum vexillum. It contains; • Video (MP4) and image files (JPG and ARW) of underwater habitats and species taken during the surveys • Drone aerial images and videos of the current layout of the pontoons and mooring buoys (JPG and DNG and MP4). • An Excel spreadsheet of sites surveyed • Data recording forms – PDF copies of dive log sheets and recording forms This data accompanies; Holt, R.H.F. 2018. Didemnum vexillum: survey of distribution and extent in Holyhead Harbour – November 2020. NRW Evidence report no. 538. 29 pp. This is the raw data from a dive survey of Holyhead harbour in November 2020, which focussed on mapping the distribution of the invasive non-native species Carpet seasquirt, Didemnum vexillum. It contains; • Video (MP4) and image files (JPG and ARW) of underwater habitats and species taken during the surveys • Drone aerial images and videos of the current layout of the pontoons and mooring buoys (JPG and DNG and MP4). • An Excel spreadsheet of sites surveyed • Data recording forms – PDF copies of dive log sheets and recording forms This data accompanies; Holt, R.H.F. 2018. Didemnum vexillum: survey of distribution and extent in Holyhead Harbour – November 2020. NRW Evidence report no. 538. 29 pp. 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 Cloud Base Productions Ltd. Cloud Base Productions Ltd., Tan Hwfa, Llanllechid, Bangor, LL57 3LA rohan@cloudbasepro.co.uk www.cloudbasepro.co.uk 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 Didemnum vexillum Holyhead NRW Thesaurus 2025-01-08 geonetwork.thesaurus.local.theme.converted_nrw-keywords Seabed photography Habitat characterisation SeaDataNet Parameter Discovery Vocabulary 2024-06-19 geonetwork.thesaurus.external.theme.rdf+xml Access restrictions on this data have not been determined. It may contain sensitive information and therefore may be restricted under legislation. NRW may provide access to this dataset on request, however NRW may not release, publish or disseminate the data or derived products freely without further assessment. no limitations © CNC/NRW. Data may only be re-used externally under provision and in line with the terms of a NRW licence following an assessment of the data. English biota Irish Sea -4.65469 -4.5645 53.29446 53.3498 SeaVoX Vertical Co-ordinate Coverages 2013-02-05 creation infralittoral 2020-11-03 2020-11-05 0 10 The data accompanies the following report; Holt, R.H.F. 2018. Didemnum vexillum: survey of distribution and extent in Holyhead Harbour – November 2020. NRW Evidence report no. 538. 29 pp. Image Unknown Images - Photographs of the Didemnum vexillum seen on the dive survey, along with images of other habitats and native species (JPG and ARW). Images taken by drone of the current layout of the pontoons and mooring buoys (JPG and DNG). Movie - Videos of the results of the dive survey showing underwater habitats and species. Also, some aerial footage of the harbour (MP4). Documents - A spreadsheet of sites surveyed – see ‘Holyhead D vex survey results 20201103-05’ Excel spreadsheet (Excel) -Data recording forms – copies of dive log sheets and recording forms (PDF) 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 Video and image files – these are taken to represent the full range of different habitats in Holyhead Harbour and show a range of native and non-native species which occur in the marina as part of the survey. These videos and images were taken with underwater camera apparatus. Drone aerial images and videos of the current layout of the pontoons and mooring buoys – taken with a drone piloted by CloudBase Productions. An Excel spreadsheet of sites surveyed - ‘Holyhead D vex survey results 20201103-05’ – this is a summary of the locations of the images and sites surveyed which accompanies the report Data recording forms – PDF copies of dive log sheets and recording forms – these were filled out by the dive contractors during the survey. Video and image files – these are taken to represent the full range of different habitats in Holyhead Harbour and show a range of native and non-native species which occur in the marina as part of the survey. These videos and images were taken with underwater camera apparatus. Drone aerial images and videos of the current layout of the pontoons and mooring buoys – taken with a drone piloted by CloudBase Productions. An Excel spreadsheet of sites surveyed - ‘Holyhead D vex survey results 20201103-05’ – this is a summary of the locations of the images and sites surveyed which accompanies the report Data recording forms – PDF copies of dive log sheets and recording forms – these were filled out by the dive contractors during the survey.