Intertidal Monitoring of Eelgrass (Zostera) Beds in Carmarthen Bay and Estuaries Special Areas of Conservation (SACs) 2009
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. Data is captured to support reporting on conservation status of the piddock feature. Carmarthen Bay SAC was designated for five Annex I intertidal habitat features: Estuaries; Mudflats and sandflats not covered by seawater at low tide; Large shallow inlets and bays; Salicornia and other annuals colonising mud and sand; Atlantic salt meadows (Glauco- Puccinellietalia maritimae). Specific areas of interest include areas of eelgrass Zostera noltii in the Burry Inlet and the monitoring aimed to map the area covered by Zostera at the two sites; sample points on a grid across those areas identified to have Zostera to estimate the cover of surface species.
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS114943
- Alternative Title
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- 2009 CCW / ASML Carmarthen Bay SAC intertidal Zostera bed monitoring MRCCW16300000026
- Monitro Rhynglanwol: Zostera marina yn ACA Bae Caerfyrddin ac Aberoedd yn 2009
- Metadata Language
- English
- Lineage
-
There were two known areas of Zostera noltii - a bed on Llanrhidian Sands and a second at Penrhyn Gwyn. In order to assess the quality of the beds, grids oriented north-south and east-west, with stations spaced at 50 m intervals, were created for each area. The station coordinates were uploaded to handheld GPS units and either two or three surveyors went to each position in turn. At each station a 0.25 m2 quadrat (0.5 m x 0.5 m) was placed randomly 5 times within a radius of approximately 10 m. Random locations were achieved by standing at the station position and throwing the quadrat behind the surveyor. Digital photographs were taken of each quadrat, so that the quadrat filled the frame, and the photograph number was recorded. A count was made of the number of quadrats out of the five in which either Zostera or Spartina was present. In the first quadrat only, the following were recorded: Percentage cover of: Substratum (Mud, sand, gravel, cobble); Standing water; Zostera noltii; Green algae; Mytilus edulis; Spartina anglica; Salicornia. Zostera of less than 5% cover was recorded as One plant, Few plants or Many plants; Cerastoderma edule (None, less than 100/m2, greater than 100/m2); The depth of the black layer in centimetres (measured with a ruler); Other species or features were recorded as Present; The presence of Zostera within a 3 m radius. Zostera beds were previously mapped in 2004. Data quality and confidence was considered high as all surveys were completed by professionals and experienced marine field surveyors.
- Dataset Reference Date (Publication)
- 2012-06-30
Temporal Extent
- Begin date
- 2009-09-25
- End date
- 2012-09-24
- Topic category
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- Biota
Extent
Extent
- Geographic Extent
- ABERTAWE - SWANSEA
- Geographic Extent
- SIR GAERFYRDDIN - CARMARTHENSHIRE
))
Vertical Extent
- Medin Extent Keyword
- benthic boundary layer
Distribution
- Format Type and Description
-
-
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 layers in MapInfo Native format (Tables): - Boundaries and position of the sample stations [C] Excel spreadsheets with transect physical and species data [D] Photographs of the area, sites, samples and quadrats. [E] Marine Recorder file [MRCCW16300000026].
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Documents
()
Quality
Data quality
- Quality Scope
- Dataset
- Lineage
-
There were two known areas of Zostera noltii - a bed on Llanrhidian Sands and a second at Penrhyn Gwyn. In order to assess the quality of the beds, grids oriented north-south and east-west, with stations spaced at 50 m intervals, were created for each area. The station coordinates were uploaded to handheld GPS units and either two or three surveyors went to each position in turn. At each station a 0.25 m2 quadrat (0.5 m x 0.5 m) was placed randomly 5 times within a radius of approximately 10 m. Random locations were achieved by standing at the station position and throwing the quadrat behind the surveyor. Digital photographs were taken of each quadrat, so that the quadrat filled the frame, and the photograph number was recorded. A count was made of the number of quadrats out of the five in which either Zostera or Spartina was present. In the first quadrat only, the following were recorded: Percentage cover of: Substratum (Mud, sand, gravel, cobble); Standing water; Zostera noltii; Green algae; Mytilus edulis; Spartina anglica; Salicornia. Zostera of less than 5% cover was recorded as One plant, Few plants or Many plants; Cerastoderma edule (None, less than 100/m2, greater than 100/m2); The depth of the black layer in centimetres (measured with a ruler); Other species or features were recorded as Present; The presence of Zostera within a 3 m radius. Zostera beds were previously mapped in 2004. Data quality and confidence was considered high as all surveys were completed by professionals and experienced marine field surveyors.
Keywords
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
- NRW Thesaurus
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- intertidal
- Carmarthen Bay and Estuaries SAC
- zostera
- seagrasses (see also potamogetonaceae and hydrocharitaceae)
- zostera noltii
- Type
- Theme
Citation
- Date (Publication)
- 2023-12-31
Keywords
- SeaDataNet Parameter Discovery Vocabulary
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- Macroalgae and seagrass taxonomy-related counts
- Habitat extent
- Type
- Theme
Citation
- Date (Revision)
- 2021-01-06
Keywords
Spatial Reference System
Content
Content Information
NRW Profile
Custom Elements
- NRW Related Title
-
Intertidal SAC monitoring Carmarthen Bay SAC September 2009
Constraints
Constraints
Limitations on Public Access and Use
- Restriction type
- Other restrictions
Access Constraints Directive
- Limitations
- no limitations
Access Constraints Text
- Other constraints
-
The following data is considered OS derived data and is therefore jointly owned by NRW and the Ordnance Survey. NRW may release, publish or disseminate this data freely; providing recipients are made aware of use restrictions (See general use restrictions).
Use Constraints
- Use constraints type
- Other restrictions
- Other constraints
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© CNC/NRW and © Crown copyright 2012. All rights reserved. Natural Resources Wales, AC0000849444 Third parties seeking to re-use this data require a Licence issued by NRW. It allows re-use, reproduction and dissemination in any format or medium but only for non-commercial purposes, according to the terms and conditions of the Licence. Those seeking commercial re-use require a commercial licence available from the OS.
Metadata
Metadata
- File Identifier
- 4f4c4942-4343-5764-6473-313134393433 XML
- Metadata Language
- English
- Parent Identifier
-
Across Wales Intertidal Monitoring Survey
NRW_DS109834
- Resource type
- Dataset
- Metadata Date
- 2024-12-09T12:33:23.217Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
-
1.0