4f4c4942-4343-5764-6473-313134383630 English Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en 2026-03-03T12:28:05.728Z NRW 1.0 wel British National Grid (EPSG::27700) Colonisation, Growth and Interactions of Carpet Sea Squirt (Didemnum vexillum) Colonisation, Growth and Interactions of Carpet Sea Squirt (Didemnum vexillum) Ymlediad, twf ac ymarweithiad chwistrell for dorfol (Didemnum vexillum) Colonisation, growth and species interactions of a successful non-indigenous marine invader Didemnum vexillum. 2012-06-30 NRW_DS114860 The Carpet Sea Squirt (Didemnum vexillum) is a Invasive Non Native (INN) filter feeding marine invertebrate that forms large colonies carpetting hard structures on which it grows. Carpet Sea Squirt (Didemnum vexillum) was only confirmed in British waters in 2008. However, there are strong concerns that it will quickly colonise a much wider area as it has been found to do in other countries such as New Zealand and the USA. After an initial survey to identify the extent of colonisation, an eradication programme was undertaken by the Countryside Council for Wales. A programme of monitoring was initiated to measure the success of the eradication experiment and subsequent recolonisation and a research project undertaken in conjunction with Bangor University. The purpose of this data capture was to assess patterns of settlement, growth, colonisation and species interactions of Didemnum vexillum within Holyhead Marina from season to season. Also to look at how different disturbance magnitudes have negative or positive effects on Didemnum vexillum settlement and recruitment. The Carpet Sea Squirt (Didemnum vexillum) is a Invasive Non Native (INN) filter feeding marine invertebrate that forms large colonies carpetting hard structures on which it grows. Carpet Sea Squirt (Didemnum vexillum) was only confirmed in British waters in 2008. However, there are strong concerns that it will quickly colonise a much wider area as it has been found to do in other countries such as New Zealand and the USA. After an initial survey to identify the extent of colonisation, an eradication programme was undertaken by the Countryside Council for Wales. A programme of monitoring was initiated to measure the success of the eradication experiment and subsequent recolonisation and a research project undertaken in conjunction with Bangor University. The purpose of this data capture was to assess patterns of settlement, growth, colonisation and species interactions of Didemnum vexillum within Holyhead Marina from season to season. Also to look at how different disturbance magnitudes have negative or positive effects on Didemnum vexillum settlement and recruitment. University of Wales, Bangor. School of Ocean Sciences Bangor, Gwynedd, LL57 2DG oss011@bangor.ac.uk http://www.bangor.ac.uk Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en University of Wales, Bangor. School of Ocean Sciences Bangor, Gwynedd, LL57 2DG oss011@bangor.ac.uk http://www.bangor.ac.uk Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en CCW Marine Monitoring Team Countryside Council for Wales, Maes y Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW enquiries@naturalresourceswales.gov.uk http://naturalresourceswales.gov.uk/splash?orig=/ 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 colonial sea squirt non-native species Didemnum vexillum invasive species (alien species) Holyhead NRW Thesaurus 2025-01-08 geonetwork.thesaurus.local.theme.converted_nrw-keywords Zoobenthos taxonomic abundance SeaDataNet Parameter Discovery Vocabulary 2024-06-19 geonetwork.thesaurus.external.theme.rdf+xml This data is jointly owned by NRW and Bangor University. There are no access restrictions to this data. NRW may release, publish or disseminate it freely. no limitations © CNC/NRW and Bangor University 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 the copyright of NRW/ Bangor University 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. © CNC/NRW and Bangor University 2012 Open Government Licence 10 English biota SIR YNYS MON - ISLE OF ANGLESEY -4.64566635 -4.64053809 53.31871806 53.32210927 SeaVoX Vertical Co-ordinate Coverages 2013-02-05 creation benthic boundary layer 2011-05-17 2012-01-25 Movie Data is held on video (mini dv) tapes with streamed clips as mpegs. Image Images as held as tiffs. Delimited Analysed data in microsoft excel spreadsheet format 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 Two experiments were implemented. Fixed quadrats (0.5x1m2) were set up in 2009. Disturbance quadrats (30x30cm2) were set up in 2011. Each cell was recorded using a video camera on a monthly basis. Still images of each cell were extracted from the video and the images re-sized, stretched and \stitched\" together to give and image of the full quadrat. Percentage cover of Didemnum vexillum could the be recorded along with cover of 4 key taxonomic groups (solitary ascidians; bivalves; sponges; and macroalgae). CCW have also established a temperature logger within the vicinity of the research work. The current research is written up as part of an unpublished Graduate Research project Alun G. (2012)." Two experiments were implemented. Fixed quadrats (0.5x1m2) were set up in 2009. Disturbance quadrats (30x30cm2) were set up in 2011. Each cell was recorded using a video camera on a monthly basis. Still images of each cell were extracted from the video and the images re-sized, stretched and \stitched\" together to give and image of the full quadrat. Percentage cover of Didemnum vexillum could the be recorded along with cover of 4 key taxonomic groups (solitary ascidians; bivalves; sponges; and macroalgae). CCW have also established a temperature logger within the vicinity of the research work. The current research is written up as part of an unpublished Graduate Research project Alun G. (2012)."