Survey of distribution and extent of Didemnum vexillum in Holyhead Harbour after Storm Emma October 2018
This dataset details the presence and absence of Didemnun vexillum (an invasive non-native Carpet Sea Squirt) around North West Anglesey after March 2018, when Storm Emma destroyed Holyhead marina. Live Didemnum vexillum, previously found to be established on the marina structures and nearby boat hulls and moorings, was presumed to be distributed on marina debris around NW Anglesey. Shore and diving surveys were conducted in October 2018 in the marina area and where the bulk of floating material was washed ashore on the NW of Anglesey coast early in March 2018. D vexillum was only located on the various marina structures that survived the storm and on boat hulls and moorings in the areas where it had been found on previous surveys.
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS122967
- Alternative Title
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- Arolwg o ddosbarthiad a hyd a lled Didemnum vexillum yn Harbwr Caergybi ar ôl Storm Emma Hydref 2018
- Metadata Language
- English
- Lineage
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Intertidal areas were investigated on foot with particular care taken to inspect marina debris, underboulders, overhangs and shaded vertical surfaces where didemnids are most likely to occur. Subtidal structures and natural features investigated by diving, concentrating on the types of habitat where D vexillum had been found previously: vertical and overhanging shaded surfaces of floating pontoons, boats and mooring buoys and chains. Fixed man-made and natural habitats where didemnids are known to occur were also investigated including harbour walls, jetty pilings, rip-rap and naturally occurring boulders. The intertidal survey covered 9 areas on the NW coast of Anglesey plus Porth y Felin and Scimitar beach in Holyhead New Harbour. Diving surveys were carried out on 58 locations in the New and Old Harbour areas to include the remains of the marina, boats and moorings in the New Harbour and structures, walls, pilings and natural rocky features in the New and Old Harbours. Presence / Absence data was collected for any occurrence of D vexillum with notes made of approximate abundance and the notable presence of any other non-native species.
- Additional Information
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Holt, R.H.F. 2018. Didemnum vexillum: survey of distribution and extent in Holyhead Harbour after storm Emma, October 2018. NRW Evidence report no. 306.
- Dataset Reference Date (Publication)
- 2019-07-31
Temporal Extent
- Begin date
- 2018-10-09
- End date
- 2018-10-26
- Topic category
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- Biota
Extent
Extent
- Geographic Extent
- Wales (WLS)
))
Vertical Extent
- Medin Extent Keyword
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benthic boundary layer
Distribution
- Format Type and Description
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Database
()
- Specification
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[A] Digital versions of the contract report: Microsoft Word document; and an Adobe Portable Document Format version. [B] Excel spreadsheets with species presence absence data. [C] Photographs of habitats and species [D] Marine Recorder file.
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Database
()
Quality
Data quality
- Quality Scope
- Dataset
- Lineage
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Intertidal areas were investigated on foot with particular care taken to inspect marina debris, underboulders, overhangs and shaded vertical surfaces where didemnids are most likely to occur. Subtidal structures and natural features investigated by diving, concentrating on the types of habitat where D vexillum had been found previously: vertical and overhanging shaded surfaces of floating pontoons, boats and mooring buoys and chains. Fixed man-made and natural habitats where didemnids are known to occur were also investigated including harbour walls, jetty pilings, rip-rap and naturally occurring boulders. The intertidal survey covered 9 areas on the NW coast of Anglesey plus Porth y Felin and Scimitar beach in Holyhead New Harbour. Diving surveys were carried out on 58 locations in the New and Old Harbour areas to include the remains of the marina, boats and moorings in the New Harbour and structures, walls, pilings and natural rocky features in the New and Old Harbours. Presence / Absence data was collected for any occurrence of D vexillum with notes made of approximate abundance and the notable presence of any other non-native species.
Keywords
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
- NRW Thesaurus
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- invasive species (alien species)
- Invasive Non-Native Species (INNS)
- Didemnum vexillum
- colonial sea squirt
- Holyhead
- marinas and marine docks
- Type
- Theme
Citation
- Date (Publication)
- 2023-12-31
Keywords
- SeaDataNet Parameter Discovery Vocabulary
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- Man-made structures
- Habitat characterisation
- Type
- Theme
Citation
- Date (Revision)
- 2021-01-06
Spatial Reference System
Content
Content Information
NRW Profile
Custom Elements
Constraints
Constraints
Limitations on Public Access and Use
- Restriction type
- Other restrictions
Access Constraints Directive
- Limitations
- no limitations
Access Constraints Text
- Other constraints
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There are no access restrictions on this data. NRW may release, publish or disseminate it freely.
Use Constraints
- Use constraints type
- Other restrictions
- Other constraints
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© 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. Attribution statement: Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved.
Metadata
Metadata
- File Identifier
- 4f4c4942-4343-5764-6473-313232393637 XML
- Metadata Language
- English
- Resource type
- Dataset
- Metadata Date
- 2024-05-31T09:41:01.049Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
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1.0