Intertidal Monitoring of Eelgrass (Zostera marina) Beds in Pen Llyn ar Sarnau Special Areas of Conservation (SACs) in 2004/2005
The Habitats Directive establishes that the management of Special Areas of Conservation (SACs) should aim to achieve the favourable conservation status of habitat and species features listed within its Annex I and Annex II. For SACs in Wales, the Countryside Council for Wales (CCW) is therefore required to report on a regular basis on whether features are in favourable conservation status. Seagrass beds develop in intertidal and shallow subtidal areas on sands and muds. They may be found in marine inlets and bays but also in other areas, such as lagoons and channels, which are sheltered from significant wave action. Eelgrass (Zostera marina), is considered to be scarce (present in 16-100 ten km squares) is protected through the EC Habitats Directive and is classed as a UK Biodiversity Action Plan (BAP) Priority Habitat. In particular, seagrass meadows are used as a refuge area by several juvenile commercially important fish species, and similarly provide an important food source for wildfowl such as Brent geese. As a result of their dense root networks, together with a certain degree of wave attenuation and the trapping of sediment particles which further encourages sedimentation, seagrass beds help to stabilise the underlying substratum, thereby playing an important role in terms of coastal defence and the reduction of coastal erosion (Davison and Hughes, 1998). As such, in addition to their biological function and conservation importance, they are also of considerable economic importance. Human activity in the coastal zone (pollution, dredging boat mooring etc) can affect seagrass distribution or even destroy the beds completely. The purpose of this data capture was to map the current known intertidal extent of the Zostera biotope, develop a survey methodology to determine grass density, record damage to the beds caused by physical impacts, develop an index of disease and record species (epibiota) on the Zostera and adjacent sediment.
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS102010
- Alternative Title
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- 2004 CCW / IECS Pen Llyn a'r Sarnau SAC Zostera marina monitoring MRCCW3020000000D
- 2005 CCW / IECS Pen Llyn a'r Sarnau SAC Zostera marina monitoring MRCCW3020000001A
- Monitro Rhynglanwol: Zostera marina yn ACA Pen Llyn a'r Sarnau yn 2004/2005
- Metadata Language
- English
- Lineage
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The extent of the Zostera was mapped on foot by walking around the biotope perimeter recording the boundary position with a portable dGPS system. Representative photographs were taken throughout the survey. The density of the seagrass was measure in 2004. 12 sampling stations of 0.07m2 were chosen at random and blades/leaves within the area counted to calculate blade density per m2. dGPS positions were recorded at each site. In 2005 sample points were chosen based on a grid system with sampling carried out at 25 m intervals along transect lines 50 m apart. A GPS and photograph were taken at each point and a quadrat of 50 cm x 50 cm was used to record Zostera marina cover, cover of Enteromorpha sp and the associated faunal species and the description of substratum. Physical damage was measured using dGPS points taken where any signs of physical damage were observed and notes recorded in situ on extent and type. Zostera marina beds were mapped during the intertidal phase 1 survey during 1997 and CCW contracted IECS to follow up these records with a monitoring program.
- Dataset Reference Date (Publication)
- 2008-12-31
Temporal Extent
- Begin date
- 2004-07-06
- End date
- 2005-08-07
- Topic category
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- Biota
Extent
Extent
- Geographic Extent
- Wales (WLS)
))
Vertical Extent
- Medin Extent Keyword
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benthic boundary layer
Distribution
- Format Type and Description
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Documents
Documents
()
- Specification
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[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): - Positions of quadrats at Porth Dinllaen - 2004. - Positions of quadrats at Afon Wen and Black Rock Sands - 2005. - Translations from the above MapInfo Tables are retained in ESRI Shapefile and MapInfo Interchange formats. [C] Excel spreadsheets for quadrat, species data - 2004/5. [D] Photographs from each location and quadrat. [E] Marine Recorder file: MRCCW3020000000D, MRCCW3020000001A
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Documents
Documents
()
Quality
Data quality
- Quality Scope
- Dataset
- Lineage
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The extent of the Zostera was mapped on foot by walking around the biotope perimeter recording the boundary position with a portable dGPS system. Representative photographs were taken throughout the survey. The density of the seagrass was measure in 2004. 12 sampling stations of 0.07m2 were chosen at random and blades/leaves within the area counted to calculate blade density per m2. dGPS positions were recorded at each site. In 2005 sample points were chosen based on a grid system with sampling carried out at 25 m intervals along transect lines 50 m apart. A GPS and photograph were taken at each point and a quadrat of 50 cm x 50 cm was used to record Zostera marina cover, cover of Enteromorpha sp and the associated faunal species and the description of substratum. Physical damage was measured using dGPS points taken where any signs of physical damage were observed and notes recorded in situ on extent and type. Zostera marina beds were mapped during the intertidal phase 1 survey during 1997 and CCW contracted IECS to follow up these records with a monitoring program.
Keywords
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
- NRW Thesaurus
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- Pen Llyn a'r Sarnau SAC
- marine biology (subtidal biology) (littoral biology) (sublittoral biology)(intertidal biology)(see also seashore)
- Special Areas of Conservation (SAC) - SAC monitoring
- Porth Fechan
- Porth Dinllaen
- Black Rock Sands
- zostera marina
- eelgrass
- seagrasses (see also potamogetonaceae and hydrocharitaceae)
- zostera
- posidoniaceae
- Type
- Theme
Citation
- Date (Publication)
- 2023-12-31
Keywords
- SeaDataNet Parameter Discovery Vocabulary
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- Habitat extent
- Type
- Theme
Citation
- Date (Revision)
- 2021-01-06
Spatial Reference System
Content
Content Information
NRW Profile
Custom Elements
- NRW Related Title
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Intertidal Monitoring of Zostera marina in Pen Llyn a'r Sarnau SAC in 2004/2005
Constraints
Constraints
Limitations on Public Access and Use
- Restriction type
- Other 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
- Use constraints type
- Other restrictions
- Other constraints
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© CNC/NRW 2008. 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
- File Identifier
- 4f4c4942-4343-5764-6473-313032303130 XML
- Metadata Language
- English
- Parent Identifier
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Natural Resources Wales (NRW) Marine Benthic Species and Habitat Collation Held in Marine Recorder
NRW_DS114501
- Resource type
- Dataset
- Metadata Date
- 2024-05-31T09:40:26.056Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
-
1.0