(Draft) Monitoring of a Maerl Bed in the Milford Haven Waterway, Pembrokeshire 2010

Maerl is a collective term for several species of red seaweed, with hard, chalky skeletons. It is rock hard and, unlike other seaweeds, it grows as unattached rounded nodules or short, branched shapes on the seabed. Like all seaweeds, maerl needs sunlight to grow, and it only occurs to a depth of about 20 m. Maerl can form large beds, when the conditions are right – a fast tidal flow or sufficient wave action to remove fine sediments, but not strong enough to break the brittle maerl branches. Within these beds, layers of dead maerl build up with a thin layer of pink, living maerl on the top. Maerl beds are classed as a UK Biodiversity Action Plan (BAP) priority habitat, listed under the Annex 1 of the Habitats Directive, is on the list of OSPAR's List of Threatened and/or Declining Species and Habitats (Region 3 - Celtic Sea), and the habitat supports a number of UKBAP priority species, and species of principal important for the purpose of conservation of biodiversity under the Natural Environment and Rural Communities Act 2006. This data contains the results of a monitoring exercise undertaken to assess the status of the maerl bed in the Haven for the reporting purposes, and also to compare with baseline data gathered in 2005 to identify any trends. The information contributes to UK BAP monitoring and reporting obligations and to the management of the Pembrokeshire Marine Special Area of Conservation (SAC). This dataset forms part of repeated monitoring of 6 sites within the maerl bed in the Milford Haven waterway. The initial surveys were carried out in 2005.

Identification

Identifier
NRW_DS114753
Alternative Title
  • 2010 DRAFT CCW Monitoring of a Maerl Bed in the Milford Haven Waterway, Pembrokeshire, 2010 (MRCCW31200000003)
Metadata Language
English
Lineage

This project was the first repeat of a long term monitoring study (by divers) of the epibiota, infauna and sediment characteristics at six sites within the Milford Haven maerl bed. The following methods were used: - In situ quadrat cell frequency counts. - In situ cores for Particle Size Analysis. - In situ cores for infaunal analysis. - In situ surface sampling for microscopic identification of epiflora. The data quality if considered to be high. There is a high confidence in taxonomic skills of contractor and management of sub-contractors with regards to standards in taxonomy throughout the survey. This project was the first repeat of a long term monitoring study (by divers) of the epibiota, infauna and sediment characteristics at six sites within the Milford Haven maerl bed.
Dataset Reference Date (Publication)
2011-12-01

Temporal Extent

Begin date
2010-08-18
End date
2010-10-01
 
Topic category
  • Biota
Owner
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Originator
  MarineSeen -
Estuary Cottage, Bentlass, Hundleton, Pembrokeshire, SA71 5RN, Wales
http://www.marineseen.com/
 

Extent

Extent

Geographic Extent
Irish Sea
Geographic Extent
Carmarthen Bay
Geographic Extent
Wales (WLS)
N
W
E
S
Map representing the geographic extent of the dataset


 

Vertical Extent

Medin Extent Keyword

benthic boundary layer

Vertical Extent

Minimum value (metres)
3.6
Maximum value (metres)
7
Vertical CRS
 
 

Distribution

Format Type and Description
  • Database ( Marine Recorder Online - Version 2.09.02 )

    Specification

    Marine Recorder

 

Quality

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

This dataset has not been assessed for conformance to the referenced INSPIRE regulation.
Degree
false
Lineage

This project was the first repeat of a long term monitoring study (by divers) of the epibiota, infauna and sediment characteristics at six sites within the Milford Haven maerl bed. The following methods were used: - In situ quadrat cell frequency counts. - In situ cores for Particle Size Analysis. - In situ cores for infaunal analysis. - In situ surface sampling for microscopic identification of epiflora. The data quality if considered to be high. There is a high confidence in taxonomic skills of contractor and management of sub-contractors with regards to standards in taxonomy throughout the survey. This project was the first repeat of a long term monitoring study (by divers) of the epibiota, infauna and sediment characteristics at six sites within the Milford Haven maerl bed.
 

Keywords

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
  • Milford Haven
  • Pembrokeshire Marine SAC
  • Maerl beds
  • Milford Haven Waterway
  • Marine Recorder
Type
Theme

Citation

Date (Publication)
2026-10-19
Code
geonetwork.thesaurus.local.theme.converted_nrw-keywords

Keywords

SeaDataNet Parameter Discovery Vocabulary
Type
Theme

Citation

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

Spatial Reference System

Code
Latitude and Longitude (EPSG::4326)
 

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

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 Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and NRW's copyright. It is the recipient's responsibility to ensure the data is fit for the intended purpose.
 

Attribution Statement

Other constraints

Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved.
 

Licence

Other constraints
Open Government Licence
 
 
 

Metadata

Metadata

File Identifier
4f4c4942-4343-5764-6473-313134373533 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
2026-10-26T11:10:26.848Z
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
 
 

Publishing Body

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