Monitoring of Kelp Depth as an Indication of Turbidity in Pen Llyn a'r Saranac Special Area of Conservation (SAC)
Monitro dyfnder gwymon fel dynodiad o dyrfedd yn ACA Pen Llyn a'r Sarnau
Turbidity provides an indication of water clarity and water quality. The depth to which light can penetrate is reduced with increased turbidity, which may be the result of natural processes in coastal and estuarine waters but can also be caused by anthropogenic causes such as coastal construction and dredge spoil dumping. Curvie (Laminaria hyperborea) is known to be susceptible to the impacts of elevated turbidity levels and therefore changes in L. hyperborea can be an indicator of changes in turbidity. Grazing of L. hyperborea by the common sea urchin Echinus esculentus may also have an impact of numbers of kelp plant and therefore numbers of this species present must also be taken into consideration. The purpose of this data capture was to use depth measurements for the distribution of kelp Laminaria hyperborea as a monitoring indicator for medium/long-term changes in turbidity level. Also to measure the overall 'luxuriousness' (biomass) of the algal turf of the rocky reef. This information will assist with reporting on the favourable conservation status of reef features in Pen Llyn a'r Sarnau.
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
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DynodyddIdentifier
- NRW_DS111139
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Teitl AmgenAlternative Title
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- Kelp monitoring at St Tudwels West
- Kelp monitoring at Pen Cristen, Bardsey
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Laith MetadataMetadata Language
- English
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Lineage
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A transect is established on an unbroken slope of bedrock with a constant gradient. Permanent stations are not required. The diver records the depth (corrected for chart datum) and length of the stipe of the deepest kelp plant. Only established plants i.e. those with a stipe greater than 100mm in length are recorded. The diver swims directly upslope with a 3m pole, when 3 plants are touching the pole, the details are recorded. The diver swims upslope again until the pole is touching 6 plants, recording the details. The process is carried out at 5 transects at least 10m apart. The number of Common sea urchins Echinus esculentus occurring along the length of the transect are also recorded. Within these 3 zones (lower, middle and upper) algal turf is gathered from a 0.3m x 0.3m quadrat. Quadrats are repeated as time allows. In the lab the algae is washed and excess water removed and the wet weight recorded. The samples are then dried and the ash-free dry weight recorded. Detailed methodologies and descriptions can be found in Marine Monitoring Report 25b (standard operating procedures 10). Although sampling is repeated annually, poor weather conditions have meant that no data has been collected since 14/07/2005. In future volunteers may be used to assist with data collection.
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Dyddiad cyfeirnod y set ddata (Cyhoeddiad)Dataset Reference Date (Publication)
- 2009-12-31
Temporal Extent
- Begin date
- 2004-05-21
- End date
- 2009-12-31
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Categori pwncTopic category
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BiotaBiota
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Extent
Extent
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HydGeographic Extent
- Irish Sea
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HydGeographic Extent
- Cardigan Bay
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HydGeographic Extent
- Tremadog Bay
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HydGeographic Extent
- GWYNEDD - GWYNEDD
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Vertical Extent
- Medin Extent Keyword
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benthic boundary layer
Maint Fertigol
Vertical Extent
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Gwerth lleiafMinimum value (metres)
- -5.4
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Gwerth uchafMaximum value (metres)
- -10
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System Gyfeirio Cydlynu FertigolVertical CRS
Distribution
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Fformat - Math a DisgrifiadFormat Type and Description
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Documents
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)
- Specification
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Data provided as excel spreadsheets and/or word documents. Incidental video on mini DV tapes, incidental images as .jpgs
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Documents
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Quality
Ansawdd Data
Data quality
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Cwmpas AnsawddQuality Scope
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DatasetDataset
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CydymffurfiadConformity
- 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
- Explanation
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This dataset has not been assessed for conformance to the referenced INSPIRE regulation.
- Degree
- false
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Lineage
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A transect is established on an unbroken slope of bedrock with a constant gradient. Permanent stations are not required. The diver records the depth (corrected for chart datum) and length of the stipe of the deepest kelp plant. Only established plants i.e. those with a stipe greater than 100mm in length are recorded. The diver swims directly upslope with a 3m pole, when 3 plants are touching the pole, the details are recorded. The diver swims upslope again until the pole is touching 6 plants, recording the details. The process is carried out at 5 transects at least 10m apart. The number of Common sea urchins Echinus esculentus occurring along the length of the transect are also recorded. Within these 3 zones (lower, middle and upper) algal turf is gathered from a 0.3m x 0.3m quadrat. Quadrats are repeated as time allows. In the lab the algae is washed and excess water removed and the wet weight recorded. The samples are then dried and the ash-free dry weight recorded. Detailed methodologies and descriptions can be found in Marine Monitoring Report 25b (standard operating procedures 10). Although sampling is repeated annually, poor weather conditions have meant that no data has been collected since 14/07/2005. In future volunteers may be used to assist with data collection.
Keywords
Allweddair
Keywords
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MathType
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ThemeTheme
Dyfyniad
Citation
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Dyddiad (Cyhoeddiad)Date (Publication)
- 2008-06-01
Allweddair
Keywords
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NRW Thesaurus
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- sea urchins
- kelp
- turbidity
- echinus esculentus
- laminaria hyperborea
- water clarity
- St Tudwels West
- Pen Llyn a'r Sarnau cSAC
- Pen Cristen
- marine monitoring (see also marine surveys)
- common urchin
- St Tudwals Islands
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MathType
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ThemeTheme
Dyfyniad
Citation
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Dyddiad (Cyhoeddiad)Date (Publication)
- 2026-08-27
Allweddair
Keywords
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MathType
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ThemeTheme
Dyfyniad
Citation
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Dyddiad (Cyhoeddiad)Date (Publication)
- 2024-06-19
Allweddair
Keywords
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IPSV Subjects List
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- Water quality
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MathType
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ThemeTheme
Dyfyniad
Citation
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Dyddiad (Cyhoeddiad)Date (Publication)
- 2020-11-18
Spatial Reference System
Content
Gwybodaeth Cynnwys
Content Information
Proffil CNC
NRW Profile
Elfennau CNC
Custom Elements
Constraints
Constraints
Limitations on Public Access and Use
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Math o GyfyngiadRestriction type
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Other restrictionsOther restrictions
Access Constraints Directive
- Limitations
- no limitations
Access Constraints Text
- Other constraints
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There are no access restrictions to this data. NRW may release, publish or disseminate it freely.
Use Constraints
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Cyfyngiadau DefnyddioUse constraints type
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Other restrictionsOther restrictions
- Other constraints
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© CNC/NRW 2009 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 NRW's copyright, 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.
Metadata
Metadata
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Dynodydd FfeilFile Identifier
- 4f4c4942-4343-5764-6473-313131313339 XML
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Laith MetadataMetadata Language
- English
- Parent Identifier
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Across Wales Diving Monitoring Project (2004)
NRW_DS109743
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Math o adnoddResource type
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DatasetDataset
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Dyddiad MetadataMetadata Date
- 2026-09-28T14:13:01.421Z
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Enw Safonol MetadataMetadata Standard Name
- NRW
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Fersiwn MetadataMetadata Standard Version
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1.0