Special Area of Conservation (SAC) Monitoring: Shad Egg Survey on the River Wye (2011)
The River Wye rises on Plynlimon in the Cambrian Mountains and flows in a generally south-easterly direction before entering the Severn Estuary at Chepstow. The river is designated as a Special Area of Conservation (SAC) under the Habitats Directive for several features, including salmon, lamprey species, and shad. Twaite shad (Alosa fallax) and allis shad (Alosa alosa) are anadromous members of the family Clupeidae (herring). In Britain, significant populations of twaite shad are known to spawn in the Rivers Severn, Wye, Usk, and Tywi. However, it remains uncertain whether a breeding population of allis shad still exists. Populations of both species are threatened across Europe, primarily due to barriers to migration and water quality issues.
The purpose of this data capture was to assess conservation status by summarising existing data for the site, undertaking a baseline survey, and comparing the results with those from previous datasets. The survey covered the Welsh section of the River Wye, from Builth Wells to Monmouth, and was conducted during May, June, and July 2011.
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS114673
- Alternative Title
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- Shad Egg Survey River Wye 2011 - CCW - Report no. 11/8/4 CCW000800000000A
- Metadata Language
- English
- Lineage
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Environment Agency Wales (EAW) and the Countryside Council for Wales (CCW) recorded shad egg survey data for the River Wye over a period of six years, although extensive sampling data are only available for 1999, 2003, and 2004. The standard methodology described by Hillman et al. (2003) was modified to reduce the level of sampling required at sites where shad eggs were present. This enabled the JNCC (2005) target to be assessed while allowing a greater number of sites to be surveyed within the available time. Confidence in this dataset is high.
- Dataset Reference Date (Publication)
- 2012-01-31
Temporal Extent
- Begin date
- 2011-05-24
- End date
- 2011-07-13
- Topic category
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- Biota
Extent
Extent
- Geographic Extent
- SIR FYNWY - MONMOUTHSHIRE
- Geographic Extent
- POWYS - POWYS
))
Vertical Extent
- Medin Extent Keyword
- water column
Distribution
Distribution
- Format Type and Description
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Documents
(
Unknown
)
- Specification
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Project report held in Microsoft Word and Adobe PDF formats.
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Delimited
(
Unknown
)
- Specification
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Species survey data held in Microsoft Excel spreadsheet format.
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Database
(
Unknown
)
- Specification
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Species data held in Recorder 6: Shad Egg Survey, River Wye 2011, CCW Report No. 11/8/4 (CCW0008000000008).
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Image
(
Unknown
)
- Specification
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Survey photographs and associated images held in JPEG (JPG) format.
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Documents
(
Unknown
)
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
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This dataset has not been assessed for conformance to the referenced INSPIRE regulation.
- Degree
- false
- Lineage
-
Environment Agency Wales (EAW) and the Countryside Council for Wales (CCW) recorded shad egg survey data for the River Wye over a period of six years, although extensive sampling data are only available for 1999, 2003, and 2004. The standard methodology described by Hillman et al. (2003) was modified to reduce the level of sampling required at sites where shad eggs were present. This enabled the JNCC (2005) target to be assessed while allowing a greater number of sites to be surveyed within the available time. Confidence in this dataset is high.
Keywords
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
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NRW Thesaurus
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- alosa alosa
- allis shad
- alosa fallax
- Eggs
- Shad
- River Wye (Afon Gwy)
- twaite shad
- Type
- Theme
Citation
- Date (Publication)
- 2026-08-27
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
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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 2011. 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.
Licence
- Other constraints
- Open Government Licence
Metadata
Metadata
- File Identifier
- 4f4c4942-4343-5764-6473-313134363733 XML
- Metadata Language
- English
- Parent Identifier
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Freshwater Shad Monitoring Data
NRW_DS116346
- Resource type
- Dataset
- Metadata Date
- 2026-09-29T11:09:38.573Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
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1.0