Macroinvertebrates in the Glaslyn / Dwyryd Estuary
This dataset contains the results of a macroinvertebrate survey of the Glaslyn/Dwyryd Estuary undertaken in 1978 to improve understanding of the estuary's capacity to support wading birds that might be displaced by barrage construction. The survey was designed to assess the ability of the estuary to accommodate wading bird populations displaced from other estuaries along the Irish Sea flyway. The study also provided information relevant to the management of the adjacent Morfa Harlech National Nature Reserve and increased knowledge of the marine fauna of the area.
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS111147
- Metadata Language
- English
- Lineage
-
A total of 82 sampling stations were established across the estuary. At each station, five core samples were collected. Four samples were washed through a sieve, and the retained material was preserved in 5% formalin. These samples were subsequently examined in the laboratory, where the animals present were identified and counted. The percentage volume of fine sediment was determined, and a measure of organic content was recorded. The fifth core sample was retained for sediment analysis. Salinity measurements of estuarine water were obtained during both a high spring tide and a high neap tide. This survey forms part of a series of studies of the Gwynedd estuaries undertaken to assess their capacity to support wading birds.
- Dataset Reference Date (Publication)
- 1978-07-31
Temporal Extent
- Begin date
- 1978-01-01
- End date
- 1978-03-31
- Topic category
-
- Biota
Extent
Extent
- Geographic Extent
- GWYNEDD - GWYNEDD
- Geographic Extent
- Wales (WLS)
))
Vertical Extent
- Medin Extent Keyword
- soil and sediment
Distribution
Distribution
- Format Type and Description
-
-
Database
(
)
- Specification
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Available in JNCC's copy of Marine Recorder (JNCCMNCR10000633).
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Documents
(
)
- Specification
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Hardcopy report
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Database
(
)
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
-
A total of 82 sampling stations were established across the estuary. At each station, five core samples were collected. Four samples were washed through a sieve, and the retained material was preserved in 5% formalin. These samples were subsequently examined in the laboratory, where the animals present were identified and counted. The percentage volume of fine sediment was determined, and a measure of organic content was recorded. The fifth core sample was retained for sediment analysis. Salinity measurements of estuarine water were obtained during both a high spring tide and a high neap tide. This survey forms part of a series of studies of the Gwynedd estuaries undertaken to assess their capacity to support wading birds.
Keywords
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
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NRW Thesaurus
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- estuaries (see also specific estuary names)
- wading birds
- marine sediments (coastal sediments) (intertidal sediments) (subtidal sediments)
- marine invertebrates
- macroinvertebrates
- Glaslyn Dwyryd estuary
- Type
- Theme
Citation
- Date (Publication)
- 2026-08-27
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2024-06-19
Spatial Reference System
Content
Content Information
NRW Profile
Custom Elements
- NRW Related Title
-
Survey of macroinvertebrate populations in the Glaslyn / Dwyryd estuary complex
Constraints
Constraints
Limitations on Public Access and Use
- Restriction type
- Other restrictions
Access Constraints Directive
- Limitations
- no limitations
Access Constraints Text
- Other constraints
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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
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© CNC/NRW 1991 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.
Attribution Statement
- Other constraints
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Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved.
Metadata
Metadata
- File Identifier
- 4f4c4942-4343-5764-6473-313131313437 XML
- Metadata Language
- English
- Resource type
- Dataset
- Metadata Date
- 2026-10-02T09:38:21.567Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
-
1.0