Volunteer Diver Seagrass Zostera marina Surveys Porth Dinllaen (2009)
Seagrass is the only marine flowering plant found subtidally in the UK and seagrass beds are considered of National importance. In 2009 Zostera marina was the focus of former Countryside Council for Wales (CCW), now part of Natural Resources Wales (NRW), volunteer dive surveys at Porth Dinllaen in Pen Llyn a'r Sarnau Special Area of Conservation (SAC) to estimate the extent of the bed. The survey is a continuation of a 2008 pilot, and is due to be re-surveyed before 2012 to start to build up a picture of variation in the extent of the seagrass bed at the site. The main objectives of this project were to: 1. Test methods to measure extent of large seagrass beds using volunteers 2. Estimate density and measure depth of live seagrass in different parts of the bed 3. Make note of any unusual features of the seagrass bed 4. Compare with results and success of 2008 surveys
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS111487
- Alternative Title
-
- 2009 CCW Porth Dinllaen Seagrass Survey MRMES00200000011
- Seagrass surveys in Porth Dinllaen
- Arolygon gan ddeifars gwirfoddol ar wellt y gamlas Zostera marina, Pen Llyn ac Aberdaugleddau 2009
- Metadata Language
- English
- Lineage
-
Data is captured by using volunteer divers who are CMAS 2 star qualified or equivalent with a minimum of 60 dives each. Volunteers estimated the extent of large seagrass beds using rapid unmarked transects analysis, using a GPS surface tracking buoy, noting the time and depth of features of the seagrass bed (eg: where the bed starts or stops, or the position of 'mooring scars'). This method was compared with the success when some divers swam towards a fixed underwater acoustic marker (transponder) with a homing device, noting the distance and bearing to the transponder to note the key features. Wherever possible, quadrats were taken at stations along transects and the presence of flowering, seeding and wasting were noted, together with any associated, potentially threatening or BAP species. Survey methods and success were compared to the 2008 survey methods and results, and the technique's feasibility for future volunteer surveys discussed.
- Dataset Reference Date (Publication)
- 2009-12-31
Temporal Extent
- Begin date
- 2009-06-14
- End date
- 2009-07-05
- Topic category
-
- Biota
Extent
Extent
- Geographic Extent
- GWYNEDD - GWYNEDD
))
Vertical Extent
- Medin Extent Keyword
-
benthic boundary layer
Vertical Extent
- Minimum value (metres)
- 0
- Maximum value (metres)
- -6.5
- Vertical CRS
Distribution
- Format Type and Description
-
-
Database
Database
()
- Specification
-
[A] Transects and density data are MapInfo TAB files. [B] Species data held in excel spreadsheets. [C] Seasearch data held in Marine Recorder. [D] Images as JPGs [E] Summary report as word file.
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Database
Database
()
Quality
Data quality
- Quality Scope
- Dataset
- Lineage
-
Data is captured by using volunteer divers who are CMAS 2 star qualified or equivalent with a minimum of 60 dives each. Volunteers estimated the extent of large seagrass beds using rapid unmarked transects analysis, using a GPS surface tracking buoy, noting the time and depth of features of the seagrass bed (eg: where the bed starts or stops, or the position of 'mooring scars'). This method was compared with the success when some divers swam towards a fixed underwater acoustic marker (transponder) with a homing device, noting the distance and bearing to the transponder to note the key features. Wherever possible, quadrats were taken at stations along transects and the presence of flowering, seeding and wasting were noted, together with any associated, potentially threatening or BAP species. Survey methods and success were compared to the 2008 survey methods and results, and the technique's feasibility for future volunteer surveys discussed.
Keywords
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
- NRW Thesaurus
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- zostera marina
- eelgrass
- seagrasses (see also potamogetonaceae and hydrocharitaceae)
- zostera
- posidoniaceae
- Porth Dinllaen
- Pen Llyn a'r Sarnau cSAC
- Type
- Theme
Citation
- Date (Publication)
- 2023-12-31
Keywords
- SeaDataNet Parameter Discovery Vocabulary
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- Macroalgae and seagrass taxonomy-related counts
- Type
- Theme
Citation
- Date (Revision)
- 2021-01-06
Keywords
Spatial Reference System
Content
Content Information
NRW Profile
Custom Elements
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 2009. 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
- 4f4c4942-4343-5764-6473-313131343837 XML
- Metadata Language
- English
- Parent Identifier
-
Across Wales Diving Monitoring Project (2004)
NRW_DS109743
- Resource type
- Dataset
- Metadata Date
- 2024-05-31T09:22:53.063Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
-
1.0