4f4c4942-4343-5764-6473-313134363733 English NRW_DS116346 Master Reference Data Team Natural Resources Wales, Maes y Fynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW enquiries@naturalresourceswales.gov.uk http://naturalresourceswales.gov.uk/splash?orig=/ 2026-09-29T11:09:38.573Z NRW 1.0 wel utf8 British National Grid (EPSG::27700) Special Area of Conservation (SAC) Monitoring: Shad Egg Survey on the River Wye (2011) Special Area of Conservation (SAC) Monitoring: Shad Egg Survey on the River Wye (2011) Arolwg o Wyau Herlynod a Gwangod Afon Gwy Shad Egg Survey River Wye 2011 - CCW - Report no. 11/8/4 CCW000800000000A 2012-01-31 NRW_DS114673 http://naturalresources.wales/ 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. 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. Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Countryside Council for Wales (CCW) Countryside Council for Wales, Maes y Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW enquiries@naturalresourceswales.gov.uk http://naturalresourceswales.gov.uk/splash?orig=/ Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Species distribution GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme alosa alosa allis shad alosa fallax Eggs Shad River Wye (Afon Gwy) twaite shad NRW Thesaurus 2026-08-27 geonetwork.thesaurus.local.theme.converted_nrw-keywords There are no access restrictions to this data. NRW may release, publish or disseminate it freely. no limitations © 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. Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. Open Government Licence 100 English biota SIR FYNWY - MONMOUTHSHIRE POWYS - POWYS -3.44303506 -2.60733549 51.70567181 52.23079918 SeaVoX Vertical Co-ordinate Coverages 2013-02-05 creation water column 2011-05-24 2011-07-13 Documents Unknown Project report held in Microsoft Word and Adobe PDF formats. Delimited Unknown Species survey data held in Microsoft Excel spreadsheet format. Database Unknown Species data held in Recorder 6: Shad Egg Survey, River Wye 2011, CCW Report No. 11/8/4 (CCW0008000000008). Image Unknown Survey photographs and associated images held in JPEG (JPG) format. 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 2010-12-08 This dataset has not been assessed for conformance to the referenced INSPIRE regulation. false 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. 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.