SAC Monitoring: Afon Tywi Shad Egg Survey (2012)

Monitro ACA: Arolygu Wyau Gwangod (Alosa fallax) a Herlynod (Alosa alosa) yn Afon Tywi (2012)

The Afon Tywi is designated as a Special Area of Conservation (SAC) under the EC Habitats Directive (92/43/EEC) for several qualifying features, including twaite shad (Alosa fallax) and allis shad (Alosa alosa). Shad are migratory members of the Clupeidae (herring) family that ascend rivers to spawn in late spring. Populations of both species are threatened across Europe, primarily due to barriers to migration and issues relating to water quality. In the UK, significant populations of shad spawn in the Rivers Severn, Usk, Wye, and Tywi.

The former Countryside Council for Wales (CCW), Environment Agency Wales (EAW), and now Natural Resources Wales (NRW) are responsible for monitoring the condition of shad populations within SACs and ensuring the maintenance of favourable conservation status at these designated sites. The Joint Nature Conservation Committee (JNCC) published Common Standards Monitoring Guidance for Freshwater Fauna (JNCC, 2005), which outlines the mandatory and discretionary attributes and targets for monitoring freshwater fish. These include targets relating to shad populations, river flow, water quality, and river morphology.

The purpose of this data collection was to facilitate the assessment of the favourable conservation status of shad within the Afon Tywi. Confidence in this dataset is high, as the surveys were undertaken by experienced staff.

Dynodydd Identifier: NRW_DS115312

Teitl Amgen Alternative Title

Shad egg Survey Afon Tywi 2012 - CCW - Report No. 12/8/4 CCW000800000000P

Laith Metadata Metadata Language: English

Lineage: Countryside Council for Wales (CCW) and Environment Agency Wales (EAW) staff monitored the spawning distribution of shad at 13 sample sites within 60 km of the main river corridor during the 2012 spawning season. The standard methodology was modified to reduce the level of sampling required at sites where shad eggs were present. This enabled the Common Standards Monitoring (CSM) target to be assessed while allowing a greater number of sites to be surveyed within the available time.

The methodology described by Hillman et al. (2003) was adapted so that a minimum of 10 kick samples was undertaken at each site, with the number of eggs recorded for each sample. If 10 or more shad eggs were recorded after 10 kick samples, the survey was terminated. However, if fewer than 10 shad eggs were recorded, kick sampling continued until either 10 eggs had been found or a maximum of 25 kick samples had been completed.

Additional Information: Garrett, H.M., Thomas, Rh. & Hatton-Ellis, T.W. (2012). Afon Tywi SAC shad egg survey 2012. CCW Staff Science Report No. 12/8/4. 37pp, CCW. Bangor.

Dyddiad cyfeirnod y set ddata (Cyhoeddiad) Dataset Reference Date (Publication): 2013-05-31

Temporal Extent

Begin date: 2012-05-22

End date: 2012-05-29

Categori pwnc Topic category

Biota

Biota

Perchennog

Owner

Natural Resources Wales (NRW) -

Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales

http://naturalresources.wales/?lang=en

Cychwynnwr

Originator

Countryside Council for Wales (CCW) -

Countryside Council for Wales, Maes y Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW

http://naturalresourceswales.gov.uk/splash?orig=/

Cychwynnwr

Originator

Environment Agency Wales (EA Wales) -

Cambria House, 29 Newport Road, Cardiff, CF24 0TP, Wales

www.environment-agency.gov.uk

Cychwynnwr

Originator

Natural Resources Wales (NRW) -

Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales

http://naturalresources.wales/?lang=en

Extent

Hyd Geographic Extent: SIR GAERFYRDDIN - CARMARTHENSHIRE

Dosbarthiad

Distribution

Fformat - Math a Disgrifiad Format Type and Description

Documents ( Unknown )

Specification

Project report held in Microsoft Word and Adobe PDF formats within Ffynnon (NRW-13-014651; NRW-13-019708).
Image ( Unknown )

Specification

Survey site photographs held in JPEG format (Document Reference: DCT-12-229420).
Geographic Information System ( Unknown )

Specification

GIS layers held in MapInfo TAB format, used to produce the associated maps.

Ansawdd Data

Data quality

Cwmpas Ansawdd Quality Scope: Dataset

Dataset

Cydymffurfiad 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: Countryside Council for Wales (CCW) and Environment Agency Wales (EAW) staff monitored the spawning distribution of shad at 13 sample sites within 60 km of the main river corridor during the 2012 spawning season. The standard methodology was modified to reduce the level of sampling required at sites where shad eggs were present. This enabled the Common Standards Monitoring (CSM) target to be assessed while allowing a greater number of sites to be surveyed within the available time.

The methodology described by Hillman et al. (2003) was adapted so that a minimum of 10 kick samples was undertaken at each site, with the number of eggs recorded for each sample. If 10 or more shad eggs were recorded after 10 kick samples, the survey was terminated. However, if fewer than 10 shad eggs were recorded, kick sampling continued until either 10 eggs had been found or a maximum of 25 kick samples had been completed.

Allweddair

Keywords

GEMET - INSPIRE themes, version 1.0

Species distribution

Math Type: Theme

Theme

Dyfyniad

Citation

Dyddiad (Cyhoeddiad) Date (Publication): 2008-06-01

Code: geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme

Allweddair

Keywords

NRW Thesaurus

alosa alosa
allis shad
Special Area of Conservation Monitoring
Special Areas of Conservation (SAC) - SAC monitoring
twaite shad
river Tywi (afon Tywi)
Shad
alosa fallax

Math Type: Theme

Theme

Dyfyniad

Citation

Dyddiad (Cyhoeddiad) Date (Publication): 2026-08-27

Code: geonetwork.thesaurus.local.theme.converted_nrw-keywords

Code: British National Grid (EPSG::27700)

Gwybodaeth Cynnwys

Content Information

Proffil CNC

NRW Profile

Elfennau CNC

Custom Elements

NRW Related Title: Afon Tywi SAC shad egg survey 2012

Constraints

Limitations on Public Access and Use

Math o Gyfyngiad Restriction type: Other restrictions

Other restrictions

Access Constraints Directive

Limitations: no limitations

Access Constraints Text

Other constraints: There are no access restrictions to this data. NRW may release, publish or disseminate it freely.

Use Constraints

Cyfyngiadau Defnyddio Use constraints type: Other restrictions

Other restrictions

Other constraints: © CNC/NRW 2013 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

Metadata

Dynodydd Ffeil File Identifier: 4f4c4942-4343-5764-6473-313135333132 XML

Laith Metadata Metadata Language: English

Parent Identifier: Freshwater Shad Monitoring Data
NRW_DS116346

Math o adnodd Resource type: Dataset

Dataset

Dyddiad Metadata Metadata Date: 2026-09-29T11:13:56.065Z

Enw Safonol Metadata Metadata Standard Name: NRW

Fersiwn Metadata Metadata Standard Version: 1.0

Pwynt Cyswllt

pointOfContact

Natural Resources Wales (NRW) -

Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales

http://naturalresources.wales/?lang=en

Publishing Body

Access the portal

Full access to the portal and metadata.

SAC Monitoring: Afon Tywi Shad Egg Survey (2012)

Monitro ACA: Arolygu Wyau Gwangod (Alosa fallax) a Herlynod (Alosa alosa) yn Afon Tywi (2012)

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