Intertidal Monitoring of Muddy Gravel Community (IMX.VsenMtru) in the Pen Llyn a'r Sarnau Special Area of Conservation (SAC) 2004

The results of monitoring the extent and species richness of a distinct area of mixed sediment that lies east of Llanbedrog beach. The muddy gravel community is - IMX.VsenMtru (Venerupis senegalensis and Mya truncata in lower shore or infralittoral muddy gravel), and has a high biodiversity of epifauna, flora and infauna, due to the admixture of cobbles, pebbles, gravel, sand and mud. This provides many different habitat niches. The habitat is located within the Pen Llyn a'r Sarnau Special Area of Conservation (SAC) on the lower shore at Llanbedrog. In fully marine conditions on the lower shore, this habitat can be particularly species rich due to the complex nature of the substratum supporting a high diversity of infauna and epifauna, however many factors affect the habitat, physical disturbance, bait digging, organic enrichment, introduction of non-native species etc. The purpose of this data capture was to map the current extent of muddy gravel, define the character of the muddy gravel for in situ recognition, identify current known species composition and identify location for representative core sampling and Particle Size Analysis.

Identification

Identifier
NRW_DS102011
Alternative Title
  • 2004 CCW / IECS Pen Llyn a'r Sarnau SAC muddy gravel community (IMX.VsenMtru) monitoring (MRCCW3030000000B)
Metadata Language
English
Lineage

Survey conducted on foot, working 2 hours either side of low water. The survey team identified and recorded species in situ where possible, samples were taken of any species that could not be immediately identified in the field for further analysis by experienced IECS benthic staff. Representative photos of the habitat were taken throughout the survey. A suitable location (representative of the overall nature of the biotope) was identified, and the position recorded for comparability of future surveys. At this five replicate core samples, each 10 cm diameter (0.0078 m2), and one sample for PSA were taken to establish infaunal biomass and sediment characteristics (January 2005). Distribution of IMX.VsenMtru previously mapped in the area during Phase 1 survey carried out by CCW in 1996.The extent of muddy gravel was mapped by walking around the biotope perimeter recording the boundary position with a portable dGPS. Notes were recorded in situ with respect to sediment characteristics and features of the biotope. Infaunal sample does not coincide with epibiota records. Epibiota recording of moderate confidence. Positional accuaracy of 1-5 m.
Dataset Reference Date (Publication)
2008-12-31

Temporal Extent

Begin date
2004-07-07
End date
2005-01-31
 
Topic category
  • Biota
Owner
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Originator
  Countryside Council for Wales (CCW) -
Countryside Council for Wales, Maes y Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW
http://naturalresourceswales.gov.uk/splash?orig=/
Originator
  Hull University. Institute Of Estuarine And Coastal Studies -
The University of Hull, Cottingham Road, Hull, HU6 7RX
http://www.hull.ac.uk/iecs/
 

Extent

Extent

Geographic Extent
Wales (WLS)
N
W
E
S
Map representing the geographic extent of the dataset


 

Vertical Extent

Medin Extent Keyword

benthic boundary layer
 
 

Distribution

Format Type and Description
  • Database ( Marine Recorder Online - Version 2.09.02 )

    Specification

    Marine Recorder

 

Quality

Data quality

Quality Scope
Dataset
Conformity
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

This dataset has not been assessed for conformance to the referenced INSPIRE regulation.
Degree
false
Lineage

Survey conducted on foot, working 2 hours either side of low water. The survey team identified and recorded species in situ where possible, samples were taken of any species that could not be immediately identified in the field for further analysis by experienced IECS benthic staff. Representative photos of the habitat were taken throughout the survey. A suitable location (representative of the overall nature of the biotope) was identified, and the position recorded for comparability of future surveys. At this five replicate core samples, each 10 cm diameter (0.0078 m2), and one sample for PSA were taken to establish infaunal biomass and sediment characteristics (January 2005). Distribution of IMX.VsenMtru previously mapped in the area during Phase 1 survey carried out by CCW in 1996.The extent of muddy gravel was mapped by walking around the biotope perimeter recording the boundary position with a portable dGPS. Notes were recorded in situ with respect to sediment characteristics and features of the biotope. Infaunal sample does not coincide with epibiota records. Epibiota recording of moderate confidence. Positional accuaracy of 1-5 m.
 

Keywords

Keywords

GEMET - INSPIRE themes, version 1.0
Type
Theme

Citation

Date (Publication)
2008-06-01
Code
geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme

Keywords

NRW Thesaurus
  • Pen Llyn a'r Sarnau SAC
  • Marine Recorder
  • NI biotope Muddy gravel
Type
Theme

Citation

Date (Publication)
2026-08-27
Code
geonetwork.thesaurus.local.theme.converted_nrw-keywords

Keywords

SeaDataNet Parameter Discovery Vocabulary
Type
Theme

Citation

Date (Publication)
2024-06-19
Code
geonetwork.thesaurus.external.theme.rdf+xml
 

Spatial Reference System

Code
British National Grid (EPSG::27700)
 

Content

Content Information

NRW Profile

Custom Elements

NRW Related Title

Intertidal monitoring of a muddy gravel community (VsenMtru) in Pen Llyn a'r Sarnau in 2004
 

Constraints

Constraints

Limitations on Public Access and Use

Restriction type
Other restrictions
 

Access Constraints Directive

Limitations
no limitations
 

Access Constraints Text

Other constraints

There are no access restrictions to this data. NRW may release, publish or disseminate it freely.
 

Use Constraints

Use constraints type
Other restrictions
Other constraints

© 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

Other constraints

Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved.
 

Licence

Other constraints
Open Government Licence
 
 
 

Metadata

Metadata

File Identifier
4f4c4942-4343-5764-6473-313032303131 XML
Metadata Language
English
Parent Identifier
Across Wales Intertidal Monitoring Survey

NRW_DS109834
Resource type
Dataset
Metadata Date
2026-10-19T14:36:55.965Z
Metadata Standard Name
NRW
Metadata Standard Version

1.0

pointOfContact
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
 
 

Publishing Body

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