Monitro ACA: Arolygu Wyau Gwangod (Alosa fallax) a Herlynod (Alosa alosa) yn Afon Wysg (2010-2011)
The River Usk rises in the Black Mountain range in the west of the Brecon Beacons National Park and flows eastwards before turning south to enter the Severn Estuary at Newport. The river is designated as a Special Area of Conservation (SAC) 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, 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.
The former Countryside Council for Wales (CCW), now Natural Resources Wales (NRW), is responsible for monitoring the condition of shad populations within SACs and ensuring the maintenance of favourable conservation status at these designated sites. The JNCC Common Standards Monitoring Guidance for Freshwater Fauna (2005) sets a target of "no decline in spawning distribution", which is assessed through kick sampling during May and June.
There are two principal sources of data on shad spawning within the River Usk. Environment Agency Wales (EAW), now part of Natural Resources Wales, recorded the presence or absence of shad eggs at a number of sites between 1990 and 2005, although surveys have only been conducted annually since 2003.
- Dull adnabod
- Rhychwant
- Dosbarthiad
- Ansawdd
- Allweddeiriau
- System Cyfeirio Gofodol
- Cynnwys
- Cyfyngiadau
- Cynnal a chadw
- Metadata
Dull adnabod
- Dynodydd
- NRW_DS112727
- Teitl Amgen
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- Shad Egg Survey River Usk 2011 - CCW - Report no.11/8/3 CCW0008000000009
- Shad Egg Survey River Usk 2010 - CCW - Report no.10/8/1 CCW000280000000E
- Laith Metadata
- English
- Datganiad
-
The data and associated report describe the monitoring undertaken by former CCW and EAW staff on the spawning distribution of shad during the 2010 and 2011 spawning seasons.
2010: Surveys and evidence of spawning were recorded between 26 May and 22 June.
2011: Surveys and evidence of spawning were recorded between 19 May and 6 July.
Natural Resources Wales also holds records of visible shad spawning at a single location (Usk Town, NGR SO374007) for five consecutive years, from 1997 to 2001.
The standard methodology described by Hillman et al. (2003) was modified to record only the presence or absence of shad eggs. A minimum of 10 kick samples was undertaken at each site, and the number of eggs found in each sample was recorded. If a total of 10 shad eggs was recorded, the survey was terminated. However, if fewer than 10 shad eggs were recorded, kick sampling continued until either more than 10 eggs had been found or a maximum of 25 kick samples had been undertaken.
Confidence in the dataset is high, as the work was carried out by qualified CCW monitoring staff.
- Dyddiad cyfeirnod y set ddata (Cyhoeddiad)
- 2012-01-31
Ystod amser
- Dyddiad cychwyn
- 2010-05-26
- Dyddiad gorffen
- 2011-07-06
- Categori pwnc
-
- Environment
- Biota
- Inland waters
Rhychwant
Rhychwant
- Hyd
- Wales (WLS)
))
Maint Fertigol
- Maint allweddair MEDIN
Dosbarthiad
Dosbarthiad
- Fformat - Math a Disgrifiad
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-
Documents
(
Unknown
)
- Math
-
Final reports available in Microsoft Word and Adobe PDF formats.
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Delimited
(
Unknown
)
- Math
-
Raw survey data workbooks held in Microsoft Excel format.
-
Database
(
Unknown
)
- Math
-
Species data are held in Recorder 6 under the following references: CCW000280000000E (2010), CCW0008000000009 (2011)
-
Documents
(
Unknown
)
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
-
This dataset has not been assessed for conformance to the referenced INSPIRE regulation.
- Gradd
- false
- Datganiad
-
The data and associated report describe the monitoring undertaken by former CCW and EAW staff on the spawning distribution of shad during the 2010 and 2011 spawning seasons.
2010: Surveys and evidence of spawning were recorded between 26 May and 22 June.
2011: Surveys and evidence of spawning were recorded between 19 May and 6 July.
Natural Resources Wales also holds records of visible shad spawning at a single location (Usk Town, NGR SO374007) for five consecutive years, from 1997 to 2001.
The standard methodology described by Hillman et al. (2003) was modified to record only the presence or absence of shad eggs. A minimum of 10 kick samples was undertaken at each site, and the number of eggs found in each sample was recorded. If a total of 10 shad eggs was recorded, the survey was terminated. However, if fewer than 10 shad eggs were recorded, kick sampling continued until either more than 10 eggs had been found or a maximum of 25 kick samples had been undertaken.
Confidence in the dataset is high, as the work was carried out by qualified CCW monitoring staff.
Allweddeiriau
Allweddair
- Math
- Theme
Dyfyniad
- Dyddiad (Cyhoeddiad)
- 2008-06-01
Allweddair
-
NRW Thesaurus
-
- Countryside Council for Wales (CCW)
- clupea harengus
- Clupeidae
- herring
- Eggs
- River Usk
- Shad
- alosa alosa
- survey methods (survey techniques) (survey) (surveying)
- alosa fallax
- Special Areas of Conservation (SAC) (see also Candidate Special Areas of Conservation cSAC)
- 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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River Usk shad egg survey 2011
- Teitlau cysylltiedig CNC
-
River Usk shad egg survey 2010
Cyfyngiadau
Cyfyngiadau
Cyfyngiadau ar Fynediad a Defnydd Cyhoeddus
- Math o Gyfyngiad
- Other restrictions
Cyfarwyddeb Cyfyngiadau Mynediad
- Cyfyngiadau
- no limitations
Testun cyfyngiadau mynediad
- Cyfyngiadau eraill
-
There are no access restrictions to this data. NRW may release, publish or disseminate it freely.
Defnyddiwch gyfyngiadau
- Cyfyngiadau Defnyddio
- Other restrictions
- Cyfyngiadau eraill
-
© CNC/NRW 2010 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.
Datganiad Priodoli
- Cyfyngiadau eraill
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Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved.
Metadata
Metadata
- Dynodydd Ffeil
- 4f4c4942-4343-5764-6473-313132373237 XML
- Laith Metadata
- English
- Dynodydd Rhiant
-
Condition monitoring of Special Areas of Conservation (SACs) in Wales
NRW_DS110194
- Math o adnodd
- Dataset
- Dyddiad Metadata
- 2026-09-29T11:03:41.622Z
- Enw Safonol Metadata
- NRW
- Fersiwn Metadata
-
1.0