Non Native Species data - Distribution of Carpet Sea Squirt (Didemnum vexillum) in Holyhead Marina
Didemnum vexillum is an invasive colonial ascidian that has become established world-wide having been identified in Japan, North America, northern Europe, and New Zealand, following a global expansion since the 1970’s. It forms sheet like colonies on natural and artificial hard substrata as well as benthic organisms including other ascidians and algae. The serious ecological and economic damage experienced in New Zealand and other temperate regions has led to a large investment in on-going research into the biological tolerances and spread of D. vexillum as well as rapid response, monitoring and management following introductions. In summer 2008 an MSc student from Bangor University carrying out a survey of non native species in marinas in North Wales found a sea squirt in Holyhead Harbour that looked like the invasive non native species D. vexillum. A specimen was sent to a UK expert, who confirmed in November 2008 that it was very likely to be D. vexillum. Specimens were confirmed by Gretchen Lambert (pers. com. University of Washington, USA) as being D. vexillum. The purpose of this data capture was to assess the distribution and spread of the non-native species and possible threat to native species and biodiversity of the area.
- Dull adnabod
- Rhychwant
- Dosbarthiad
- Ansawdd
- Allweddeiriau
- System Cyfeirio Gofodol
- Cynnwys
- Cyfyngiadau
- Cynnal a chadw
- Metadata
Dull adnabod
- Dynodydd
- NRW_DS109566
- Teitl Amgen
-
- Dosbarthiad Didemnum vexillum ym Marina Caergybi
- Laith Metadata
- English
- Datganiad
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A rapid assessment diver survey was completed by systematically surveying each of the pontoons. Data was collected by divers and communicated to the surface where it was mapped. Presence/Absence of Didemnum vexillum was recorded. Still images and video were also taken at random locations. Specimen samples were taken at various locations on each of the pontoon for further identification and confirmation by an expert.
- Dyddiad cyfeirnod y set ddata (Cyhoeddiad)
- 2011-02-28
Ystod amser
- Dyddiad cychwyn
- 2008-12-09
- Dyddiad gorffen
- 2008-12-10
- Categori pwnc
-
- Biota
Rhychwant
Rhychwant
- Hyd
- SIR YNYS MON - ISLE OF ANGLESEY
))
Maint Fertigol
- Maint allweddair MEDIN
-
benthic boundary layer
Maint Fertigol
- Gwerth lleiaf
- 0
- Gwerth uchaf
- 5.8
- System Gyfeirio Cydlynu Fertigol
Dosbarthiad
- Fformat - Math a Disgrifiad
-
-
Documents
Documents
()
- Math
-
[A] Abundance and distribution held as MapInfo Line layers. [B] Location of video, photographs and specimen samples held as MapInfo point layers. [C] Images held as digital video and digital photographs.
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Documents
Documents
()
Ansawdd
Ansawdd Data
- Cwmpas Ansawdd
- Dataset
- Datganiad
-
A rapid assessment diver survey was completed by systematically surveying each of the pontoons. Data was collected by divers and communicated to the surface where it was mapped. Presence/Absence of Didemnum vexillum was recorded. Still images and video were also taken at random locations. Specimen samples were taken at various locations on each of the pontoon for further identification and confirmation by an expert.
Allweddeiriau
Allweddair
- Math
- Theme
Dyfyniad
- Dyddiad (Cyhoeddiad)
- 2008-06-01
Allweddair
- NRW Thesaurus
-
- Didemnum vexillum
- non-native species
- sea squirt
- Math
- Theme
Dyfyniad
- Dyddiad (Cyhoeddiad)
- 2023-12-31
Allweddair
- SeaDataNet Parameter Discovery Vocabulary
-
- Zoobenthos generic abundance
- Math
- Theme
Dyfyniad
- Dyddiad (Adolygu)
- 2021-01-06
System Cyfeirio Gofodol
Cynnwys
Gwybodaeth Cynnwys
Proffil CNC
Elfennau CNC
- Teitlau cysylltiedig CNC
-
Survey of a non-native ascidian (sea squirt) didemnum vexillum in Holyhead harbour January 2009
Cyfyngiadau
Cyfyngiadau
Cyfyngiadau ar Fynediad a Defnydd Cyhoeddus
- Math o Gyfyngiad
- Other restrictions
Cyfarwyddeb Cyfyngiadau Mynediad
- Cyfyngiadau
- no limitations
Testun cyfyngiadau mynediad
- Cyfyngiadau eraill
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The following data is considered OS derived data and is therefore jointly owned by NRW and the Ordnance Survey. NRW may release, publish or disseminate this data freely; providing recipients are made aware of use restrictions
Defnyddiwch gyfyngiadau
- Cyfyngiadau Defnyddio
- Other restrictions
- Cyfyngiadau eraill
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© CNC/NRW and © Crown copyright [2011]. All rights reserved. Natural Resources Wales, AC0000849444 Third parties seeking to re-use this data require a Licence issued by NRW. It allows re-use, reproduction and dissemination in any format or medium but only for non-commercial purposes, according to the terms and conditions of the Licence. Those seeking commercial re-use require a commercial licence available from the OS.
Metadata
Metadata
- Dynodydd Ffeil
- 4f4c4942-4343-5764-6473-313039353636 XML
- Laith Metadata
- English
- Math o adnodd
- Dataset
- Dyddiad Metadata
- 2024-05-31T09:41:35.914Z
- Enw Safonol Metadata
- NRW
- Fersiwn Metadata
-
1.0