Intertidal Monitoring of the Number and Extent of Sea Caves, Pen Llyn ar Sarnau Special Area of Conservation (SAC) 2004

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.

Identifier: NRW_DS102026

Alternative Title

Monitro Rhynglanwol: Niferoedd a Maint Ogofau Mor, ACA Pen Llyn a'r Sarnau yn 2004

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.

Dataset Reference Date (Publication): 2009-01-31

Temporal Extent

Begin date: 2004-07-07

End date: 2004-07-07

Topic category

Biota

Owner

Natural Resources Wales (NRW)

Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales

http://naturalresources.wales/?lang=en

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

Geographic Extent: Wales (WLS)

Vertical Extent

Medin Extent Keyword: benthic boundary layer

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.

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
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

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
Friog
Sea Caves
marine biology (subtidal biology) (littoral biology) (sublittoral biology)(intertidal biology)(see also seashore)
Special Areas of Conservation (SAC) - SAC monitoring
Llwyngwril

Type: Theme

Citation

Date (Publication): 2023-12-31

Code: geonetwork.thesaurus.local.theme.converted_nrw-keywords

Keywords

SeaDataNet Parameter Discovery Vocabulary

Habitat characterisation
Habitat extent

Type: Theme

Citation

Date (Revision): 2021-01-06

Code: geonetwork.thesaurus.external.theme.rdf+xml

Code: British National Grid (EPSG::27700)

Content Information

NRW Profile

Custom Elements

NRW Related Title: Intertidal monitoring of sea caves in Pen Llyn a'r Sarnau SAC 2004

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 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

File Identifier: 4f4c4942-4343-5764-6473-313032303236 XML

Metadata Language: English

Parent Identifier: Natural Resources Wales (NRW) Marine Benthic Species and Habitat Collation Held in Marine Recorder
NRW_DS114501

Resource type: Dataset

Metadata Date: 2024-12-09T12:37:22.793Z

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

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Intertidal Monitoring of the Number and Extent of Sea Caves, Pen Llyn ar Sarnau Special Area of Conservation (SAC) 2004

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Extent

Extent

Vertical Extent

Distribution

Quality

Data quality

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Keywords

Citation

Keywords

Citation

Keywords

Citation

Spatial Reference System

Content

Content Information

NRW Profile

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Constraints

Constraints

Limitations on Public Access and Use

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