NRW_DS114753 eng NRW_DS114501 dataset Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en pointOfContact 2026-03-03T14:57:56 MEDIN 3.1.2 wel eng utf8 Latitude and Longitude (EPSG::4326) Monitoring of a Maerl Bed in the Milford Haven Waterway, Pembrokeshire 2010 Monitoring of a Maerl Bed in the Milford Haven Waterway, Pembrokeshire 2010 Monitro Gwely Marl yn nyfrffordd Aberdaugleddau, Sir Benfro, 2010 2010 DRAFT CCW Monitoring of a Maerl Bed in the Milford Haven Waterway, Pembrokeshire, 2010 MRCCW31200000003 2011-12-01 publication 4f4c4942-4343-5764-6473-313134373533 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. 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. Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en owner Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en custodian MarineSeen Estuary Cottage, Bentlass, Hundleton, Pembrokeshire, SA71 5RN, Wales fbunker@marineseen.com http://www.marineseen.com/ originator Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en distributor asNeeded Species distribution Habitats and biotopes theme GEMET - INSPIRE themes, version 1.0 2008-06-01 publication geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme survey methods (survey techniques) (survey) (surveying) Pembrokeshire Marine SAC Maerl beds Milford Haven Waterway Milford Haven theme NRW Thesaurus 2025-01-08 publication geonetwork.thesaurus.local.theme.converted_nrw-keywords Macroalgae generic abundance in water bodies theme SeaDataNet Parameter Discovery Vocabulary 2024-06-19 publication geonetwork.thesaurus.external.theme.rdf+xml otherRestrictions There are no access restrictions to this data. NRW may release, publish or disseminate it freely. no limitations otherRestrictions © CNC/NRW 2012 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. vector eng utf8 biota SeaVoX Vertical Co-ordinate Coverages 2021-01-06 revision benthic boundary layer NRW Geographic Identifiers Collection 2024-01-01 publication Irish Sea NRW Geographic Identifiers Collection 2024-01-01 publication Carmarthen Bay NRW Geographic Identifiers Collection 2024-01-01 publication Wales (WLS) -5.10687735 -5.06633182 51.69526632 51.71291344 2010-08-18 2010-10-01 3.6 7 Database [A] Published report - electronic version (pdf and MS Word) [B] Raw data - MS Excel, Marine Recorder [MRCCW31200000003] [C] Analysed data - PRIMER workspaces and MS Excel [D] Positions for sites - MapInfo dataset 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 2010-12-08 publication This dataset has not been assessed for conformance to the referenced INSPIRE regulation. false 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. 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.