Monitro Llyfrothennod Dalgylch Afon Dyfrdwy (2004)
Bullhead (Cottus gobio) is listed under Annex II of the Habitats Directive as a species of Community interest. Bullhead populations have declined across Europe in recent decades as a result of human activities. Bullhead is a designated feature of the River Dee and Bala Lake / Afon Dyfrdwy a Llyn Tegid Special Area of Conservation (SAC) in Wales.
The purpose of this data capture was to assess bullhead abundance and population structure throughout the SAC. The dataset comprises population data for bullhead (Cottus gobio) collected within the River Dee catchment since 2001, together with additional quantitative and semi-quantitative survey data collected from 2004 onwards to assess bullhead abundance.
- Dull adnabod
- Rhychwant
- Dosbarthiad
- Ansawdd
- Allweddeiriau
- System Cyfeirio Gofodol
- Cynnwys
- Cyfyngiadau
- Cynnal a chadw
- Metadata
Dull adnabod
- Dynodydd
- NRW_DS107797
- Teitl Amgen
-
- Bullhead Monitoring, Dee Catchment 2001-2004- CCW - RoC Report no. 19 CCW0002800000006
- Bullhead Monitoring - CCW - RoC Report no.19
- Laith Metadata
- English
- Datganiad
-
Relevant bullhead abundance data were extracted from the master spreadsheet supplied with the Review of Consents (RoC) report. Where quantitative and semi-quantitative surveys were undertaken at the same site and time, only the quantitative data were extracted, as the semi-quantitative data represented a subset of the quantitative survey results.
Historical data for 2001 to 2003 were collated from the North Wales Fisheries Monitoring Programme. A limited number of sites (approximately 12) were surveyed annually to obtain information on fish populations and identify trends in abundance and catch data.
Bullhead populations were also recorded as part of the Dee Stock Assessment Programme at selected sites in 2004 and through the Eel Monitoring Programme at three sites within the Dee catchment during 2004.
All sites were surveyed using electric fishing equipment in accordance with the protocols described in the Environment Agency Electric Fishing Theory and Practice Manual (1988). Two survey methodologies were employed: quantitative temporal surveys at sites monitored annually, and semi-quantitative spatial surveys at sites monitored every five years. Three fishing runs were carried out for quantitative surveys and a single fishing run for semi-quantitative surveys.
- Dyddiad cyfeirnod y set ddata (Cyhoeddiad)
- 2004-10-31
Ystod amser
- Dyddiad cychwyn
- 2001-01-01
- Dyddiad gorffen
- 2004-10-31
- Categori pwnc
-
- Biota
Rhychwant
Rhychwant
- Hyd
- POWYS - POWYS
- Hyd
- GWYNEDD - GWYNEDD
- Hyd
- SIR Y FFLINT - FLINTSHIRE
- Hyd
- SIR DDINBYCH - DENBIGHSHIRE
- Hyd
- CONWY - CONWY
- Hyd
- WRECSAM - WREXHAM
))
Dosbarthiad
Dosbarthiad
- Fformat - Math a Disgrifiad
-
-
Database
(
Unknown
)
- Math
-
Species data held in Recorder 6 under reference CCW0002800000006: Bullhead Monitoring, Dee Catchment, 2001-2004.
-
Documents
(
Unknown
)
- Math
-
Published report held in Ffynnon (DCT-10-027856).
-
Delimited
(
Unknown
)
- Math
-
Survey data and analysis held in Microsoft Excel spreadsheet format.
-
Geographic Information System
(
Unknown
)
- Math
-
Bullhead density GIS layers held in MapInfo TAB format.
-
Geographic Information System
(
Unknown
)
- Math
-
Bullhead density GIS layers held in ArcGIS format.
-
Database
(
Unknown
)
- Math
-
Archived data held under Project Number 295, Media Number 1198.
-
Database
(
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
-
Relevant bullhead abundance data were extracted from the master spreadsheet supplied with the Review of Consents (RoC) report. Where quantitative and semi-quantitative surveys were undertaken at the same site and time, only the quantitative data were extracted, as the semi-quantitative data represented a subset of the quantitative survey results.
Historical data for 2001 to 2003 were collated from the North Wales Fisheries Monitoring Programme. A limited number of sites (approximately 12) were surveyed annually to obtain information on fish populations and identify trends in abundance and catch data.
Bullhead populations were also recorded as part of the Dee Stock Assessment Programme at selected sites in 2004 and through the Eel Monitoring Programme at three sites within the Dee catchment during 2004.
All sites were surveyed using electric fishing equipment in accordance with the protocols described in the Environment Agency Electric Fishing Theory and Practice Manual (1988). Two survey methodologies were employed: quantitative temporal surveys at sites monitored annually, and semi-quantitative spatial surveys at sites monitored every five years. Three fishing runs were carried out for quantitative surveys and a single fishing run for semi-quantitative surveys.
Allweddeiriau
Allweddair
- Math
- Theme
Dyfyniad
- Dyddiad (Cyhoeddiad)
- 2008-06-01
Allweddair
-
NRW Thesaurus
-
- cottus gobio
- Dee estuary
- Special Areas of Conservation (SAC) - SAC monitoring
- bullhead
- Math
- Theme
Dyfyniad
- Dyddiad (Cyhoeddiad)
- 2026-08-27
System Cyfeirio Gofodol
Cynnwys
Gwybodaeth Cynnwys
Proffil CNC
Elfennau CNC
- Teitlau cysylltiedig CNC
-
River Dee candidate special area of conservation bullhead survey 2004
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 2004 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
-
Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved.
Metadata
Metadata
- Dynodydd Ffeil
- 4f4c4942-4343-5764-6473-313037373937 XML
- Laith Metadata
- English
- Dynodydd Rhiant
-
Freshwater Bullhead Survey Data in Wales
NRW_DS107795
- Math o adnodd
- Dataset
- Dyddiad Metadata
- 2026-09-29T11:26:07.772Z
- Enw Safonol Metadata
- NRW
- Fersiwn Metadata
-
1.0