Arolwg o lynnoedd yn SoDdGAa/ACA/AGA Migneint-Arenig-Dduallt
The Migneint-Arenig-Dduallt Proposed Site of Special Scientific Interest (pSSSI) and Special Area of Conservation (SAC) is situated in North Wales in the Snowdonia National Park. The pSSSI/SAC boundary marks the limit of a large upland block located along the eastern fringe of the National Park. The primary reasons for the site qualifying for SAC status are the large areas of blanket bog, a priority habitat under the Habitats Directive, and the upland European dry heath. Other qualifying features include two Annex I habitat lake types: (1) oligotrophic to mesotrophic standing waters with vegetation of the Littorelletea uniflorae and/or of the Isoeto-Nanojuncetea, and (2), natural dystrophic lakes and ponds. The limnological surveys (surveys of inland water) focus on the collation of site and catchment data and the collection of new data on lake bathymetry, water quality and macrophyte assemblages. A particular focus is an assessment of the current acidification and conservation status of the four lake sites. A preliminary assessment of whether the lakes are in favourable condition, as defined in the Habitats Directive, is also outlined. The primary aim of this project was to survey four lakes in the Migneint-Arenig-Dduallt pSSSI/SAC in order to build up CCWs datasets on Welsh lakes. The information collected is required for conservation site assessments, ecological quality judgements for site condition reporting, contributions to site management plans and assistance with casework issues.
- Dull adnabod
- Rhychwant
- Dosbarthiad
- Ansawdd
- Allweddeiriau
- System Cyfeirio Gofodol
- Cynnwys
- Cyfyngiadau
- Cynnal a chadw
- Metadata
Dull adnabod
- Dynodydd
- NRW_DS109993
- Teitl Amgen
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- Laith Metadata
- English
- Datganiad
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Bathymetric Surveys- undertaken at Llynnau Tryweryn, Hesgyn and Hiraethlyn in August 2002. Echo sounding transects were run in a small boat between identifiable points on the shore and marked onto field maps, the transect end point locations were also recorded using a Geographical Positioning System (GPS). This produced a cross sectional profile of the lakebed on a paper chart for each transect. Lake areas, volumes and perimeter lengths calculated using planimetry. Standard physical and morphometric parameters were calculated from the survey data. No further field investigation were required at Llyn Conwy which had sufficient morphometric information from a 1986 survey. Physico-chemical survey-Water samples collected and temperature measured at the lake outflow. Temperature and dissolved oxygen profiles taken at the deepest part of each lake. Samples for soluble reactive phosphorus (SRP), total phosphorus (TP) and total nitrogen (TN) and filter papers for chlorophyll a were analysed. Acid neutralising capacity (ANC) estimated. Aquatic macrophyte survey- zonation and maximum growing depth examined using transects, all submerged floating leaved and emergent plants recorded. Plant distribution and abundance assessed and lake type determined.
- Dyddiad cyfeirnod y set ddata (Cyhoeddiad)
- 2003-09-30
Ystod amser
- Dyddiad cychwyn
- 2002-01-31
- Dyddiad gorffen
- 2003-12-31
- Categori pwnc
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- Inland waters
- Environment
Rhychwant
Rhychwant
- Hyd
- Wales (WLS)
))
Dosbarthiad
- Fformat - Math a Disgrifiad
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Documents
(
)
- Math
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[A] Report (MS Word, pdf-format) [B] Data in spreadsheet format (MS Excel)
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Documents
(
)
Ansawdd
Ansawdd Data
- Cwmpas Ansawdd
- Dataset
- Cydymffurfiad
- 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
- Eglurhad
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This dataset has not been assessed for conformance to the referenced INSPIRE regulation.
- Gradd
- false
- Datganiad
-
Bathymetric Surveys- undertaken at Llynnau Tryweryn, Hesgyn and Hiraethlyn in August 2002. Echo sounding transects were run in a small boat between identifiable points on the shore and marked onto field maps, the transect end point locations were also recorded using a Geographical Positioning System (GPS). This produced a cross sectional profile of the lakebed on a paper chart for each transect. Lake areas, volumes and perimeter lengths calculated using planimetry. Standard physical and morphometric parameters were calculated from the survey data. No further field investigation were required at Llyn Conwy which had sufficient morphometric information from a 1986 survey. Physico-chemical survey-Water samples collected and temperature measured at the lake outflow. Temperature and dissolved oxygen profiles taken at the deepest part of each lake. Samples for soluble reactive phosphorus (SRP), total phosphorus (TP) and total nitrogen (TN) and filter papers for chlorophyll a were analysed. Acid neutralising capacity (ANC) estimated. Aquatic macrophyte survey- zonation and maximum growing depth examined using transects, all submerged floating leaved and emergent plants recorded. Plant distribution and abundance assessed and lake type determined.
Allweddeiriau
Allweddair
- Math
- Theme
Dyfyniad
- Dyddiad (Cyhoeddiad)
- 2008-06-01
Allweddair
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NRW Thesaurus
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- Llyn Hesgyn
- marine and freshwater inventory
- Physico-chemical survey
- Lakes (Limnology)
- Bathymetric survey
- Llyn Hiraethlyn
- site management
- Migneint-Arenig-Dduallt SAC
- aquatic macrophytes
- Ecological quality
- Llyn Conwy
- Llyn Tryweryn
- Favourable condition
- Habitats Directive (Directive 92/43/EEC) (EC Habitats Directive) (European Community Habitats Directive)
- Conservation site assessments
- Math
- Theme
Dyfyniad
- Dyddiad (Cyhoeddiad)
- 2026-08-27
System Cyfeirio Gofodol
Cynnwys
Gwybodaeth Cynnwys
Proffil CNC
Elfennau CNC
- Teitlau cysylltiedig CNC
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Strategic CCW conservation lake survey : a survey of lakes in the Migmeint - Arenig - Dduallt pSSSI/SAC/SPA, Wales 2002 - 03 : final report
Cyfyngiadau
Cyfyngiadau
Cyfyngiadau ar Fynediad a Defnydd Cyhoeddus
- Math o Gyfyngiad
- Other restrictions
Cyfarwyddeb Cyfyngiadau Mynediad
- Cyfyngiadau
- no limitations
Testun cyfyngiadau mynediad
- Cyfyngiadau eraill
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There are no access restrictions to this data. NRW may release, publish or disseminate it freely.
Defnyddiwch gyfyngiadau
- Cyfyngiadau Defnyddio
- Other restrictions
- Cyfyngiadau eraill
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© CNC/NRW 2003 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
- Dynodydd Ffeil
- 4f4c4942-4343-5764-6473-313039393933 XML
- Laith Metadata
- English
- Dynodydd Rhiant
-
Welsh Lakes Survey and Monitoring
NRW_DS123035
- Math o adnodd
- Dataset
- Dyddiad Metadata
- 2026-09-28T11:42:42.072Z
- Enw Safonol Metadata
- NRW
- Fersiwn Metadata
-
1.0