Intertidal Monitoring of the Number and Extent of Sea Caves, Pen Llyn ar Sarnau Special Area of Conservation (SAC) 2004
Monitro Rhynglanwol: Niferoedd a Maint Ogofau Mor, ACA Pen Llyn a'r Sarnau yn 2004

  • English
  • wel
  • All

Submerged or partially submerged sea caves are included as an Annex I type within the EU Habitats Directive (92/43/EEC). These caves may vary in size and exposure, and thus the communities associated with them vary considerably depending on the structure and extent of the cave system. Sea caves generally provide habitat for colonies of encrusting animal species, but may also have shade-tolerant algal communities at their mouth. Caves on the shore and in the shallow sublittoral zone are frequently subject to conditions of strong wave surge and tend to have floors of coarse sediment, cobbles and boulders. These materials are often highly mobile and scour the cave walls. Caves that are subject to strong wave surge are characterised by communities of mussels Mytilus edulis, barnacles Balanus crenatus, cushion sponges, encrusting bryozoans and colonial ascidians, depending on the degree of water movement and scour at particular points in the cave system. The UK has the most varied and extensive inshore sea caves on the Atlantic coast of Europe. In Wales, sea caves are important within the Pen Llyn a'r Sarnau SAC and are therefore a qualifying feature, but not a primary reason for the site selection. As such there is a requirement to assess the number and extent of intertidal sea caves within this SAC. Further background information on the surveying of sea caves in Welsh SACs can be found in Bunker and Holt (2003). Sea caves are important within the Pen Llyn a'r Sarnau SAC and are a qualifying feature. As such there is a requirement to assess the number and extent of intertidal sea caves within this SAC. The specific aims of the survey were to identify and map the location of sea caves along the coastline, use digital photography to record their extent and to measure the threat from in-fill by the railway company.

Identification

Dynodydd
Identifier
NRW_DS102026
Teitl Amgen
Alternative Title
Laith Metadata
Metadata Language
English
Lineage

The exact location of each cave was mapped using a portable dGPS to give the location at the base of each sea cave. The height and width at the entrance to the cave as well as the depth of each sea cave were estimated in the field to be used for post-survey calculations. Other land marks along the cliff face were also recorded as points of reference for future surveys and all the data was input into GIS. Digital photographs were taken of each cave and a brief description noted. Photographic evidence and relevant field notes were also used to make a post-survey assessment of any impact on the sea caves from the repair and maintenance of the railway running above the headland.
Dyddiad cyfeirnod y set ddata (Cyhoeddiad)
Dataset Reference Date (Publication)
2009-01-31

Temporal Extent

Begin date
2004-07-07
End date
2004-07-07
 
Categori pwnc
Topic category
  • Biota
    Biota
Perchennog
Owner
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Cychwynnwr
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

Hyd
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

Fformat - Math a Disgrifiad
Format Type and Description
  • Documents ( )

    Specification

    [A] Digital versions of the contract report: Microsoft Word document(s); and an equivalent Adobe Portable Document Format version [B] MapInfo GIS layer in MapInfo Native format (Tables): - Cave locations at Friog. - Translations from the above MapInfo Tables are retained in ESRI Shapefile and MapInfo Interchange formats. [C] Excel spreadsheet of cave locations, dimensions and comments. [D] Photographs from each cave location.

 

Quality

Ansawdd Data
Data quality

Cwmpas Ansawdd
Quality Scope
Dataset
Dataset
Cydymffurfiad
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

The exact location of each cave was mapped using a portable dGPS to give the location at the base of each sea cave. The height and width at the entrance to the cave as well as the depth of each sea cave were estimated in the field to be used for post-survey calculations. Other land marks along the cliff face were also recorded as points of reference for future surveys and all the data was input into GIS. Digital photographs were taken of each cave and a brief description noted. Photographic evidence and relevant field notes were also used to make a post-survey assessment of any impact on the sea caves from the repair and maintenance of the railway running above the headland.
 

Keywords

Allweddair
Keywords

GEMET - INSPIRE themes, version 1.0
Math
Type
Theme
Theme

Dyfyniad
Citation

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

Allweddair
Keywords

NRW Thesaurus
  • Friog
  • Pen Llyn a'r Sarnau SAC
  • Llwyngwril
  • Sea Caves
  • marine biology (subtidal biology) (littoral biology) (sublittoral biology)(intertidal biology)(see also seashore)
  • Special Areas of Conservation (SAC) - SAC monitoring
Math
Type
Theme
Theme

Dyfyniad
Citation

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

Allweddair
Keywords

SeaDataNet Parameter Discovery Vocabulary
Math
Type
Theme
Theme

Dyfyniad
Citation

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

Spatial Reference System

Code
British National Grid (EPSG::27700)
 

Content

Gwybodaeth Cynnwys
Content Information

Proffil CNC
NRW Profile

Elfennau CNC
Custom Elements

NRW Related Title

Intertidal monitoring of sea caves in Pen Llyn a'r Sarnau SAC 2004
 

Constraints

Constraints

Limitations on Public Access and Use

Math o Gyfyngiad
Restriction type
Other restrictions
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

Cyfyngiadau Defnyddio
Use constraints type
Other restrictions
Other restrictions
Other constraints

© 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

Dynodydd Ffeil
File Identifier
4f4c4942-4343-5764-6473-313032303236 XML
Laith Metadata
Metadata Language
English
Parent Identifier
Natural Resources Wales (NRW) Marine Benthic Species and Habitat Collation Held in Marine Recorder

NRW_DS114501
Math o adnodd
Resource type
Dataset
Dataset
Dyddiad Metadata
Metadata Date
2026-09-28T10:11:07.048Z
Enw Safonol Metadata
Metadata Standard Name
NRW
Fersiwn Metadata
Metadata Standard Version

1.0

Pwynt Cyswllt
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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