Bullhead Monitoring for the Dee Catchment (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.

Identifier: NRW_DS107797

Alternative Title

Bullhead Monitoring, Dee Catchment 2001-2004- CCW - RoC Report no. 19 CCW0002800000006
Bullhead Monitoring - CCW - RoC Report no.19

Metadata Language: English

Lineage: 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.

Dataset Reference Date (Publication): 2004-10-31

Temporal Extent

Begin date: 2001-01-01

End date: 2004-10-31

Topic category

Biota

Owner

Natural Resources Wales (NRW) -

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

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

Originator

Various -

Enquiries Unit, Maes y Fynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW

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

Originator

Environment Agency (EA) -

Millbank Tower, 25th Floor, 21//24 Millbank, London, SW1P 4XL, England

http://www.environment-agency.gov.uk/

Originator

Countryside Council for Wales (CCW) -

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

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

Originator

Natural Resources Wales (NRW) -

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

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

Extent

Geographic Extent: POWYS - POWYS

Geographic Extent: GWYNEDD - GWYNEDD

Geographic Extent: SIR Y FFLINT - FLINTSHIRE

Geographic Extent: SIR DDINBYCH - DENBIGHSHIRE

Geographic Extent: CONWY - CONWY

Geographic Extent: WRECSAM - WREXHAM

Map representing the geographic extent of the dataset

Distribution

Format Type and Description

Database ( Unknown )

Specification

Species data held in Recorder 6 under reference CCW0002800000006: Bullhead Monitoring, Dee Catchment, 2001-2004.
Documents ( Unknown )

Specification

Published report held in Ffynnon (DCT-10-027856).
Delimited ( Unknown )

Specification

Survey data and analysis held in Microsoft Excel spreadsheet format.
Geographic Information System ( Unknown )

Specification

Bullhead density GIS layers held in MapInfo TAB format.
Geographic Information System ( Unknown )

Specification

Bullhead density GIS layers held in ArcGIS format.
Database ( Unknown )

Specification

Archived data held under Project Number 295, Media Number 1198.

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: This dataset has not been assessed for conformance to the referenced INSPIRE regulation.
Degree: false

Lineage: 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.

Keywords

GEMET - INSPIRE themes, version 1.0

Species distribution

Type: Theme

Citation

Date (Publication): 2008-06-01

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

Keywords

NRW Thesaurus

cottus gobio
Dee estuary
Special Areas of Conservation (SAC) - SAC monitoring
bullhead

Type: Theme

Citation

Date (Publication): 2026-08-27

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

Code: British National Grid (EPSG::27700)

Content Information

NRW Profile

Custom Elements

NRW Related Title: River Dee candidate special area of conservation bullhead survey 2004

Constraints

Limitations on Public Access and Use

Restriction type: 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

Use constraints type: Other restrictions

Other constraints: © 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.

Attribution Statement

Metadata

File Identifier: 4f4c4942-4343-5764-6473-313037373937 XML

Metadata Language: English

Parent Identifier: Freshwater Bullhead Survey Data in Wales
NRW_DS107795

Resource type: Dataset

Metadata Date: 2026-09-29T11:26:07.772Z

Metadata Standard Name: NRW

Metadata Standard Version: 1.0

pointOfContact

Master Reference Data Team -

Natural Resources Wales, Maes y Fynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW

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

Publishing Body

Access the portal

Full access to the portal and metadata.

Bullhead Monitoring for the Dee Catchment (2004)

Identification

Temporal Extent

Extent

Extent

Distribution

Distribution

Quality

Data quality

Keywords

Keywords

Citation

Keywords

Citation

Spatial Reference System

Content

Content Information

NRW Profile

Custom Elements

Constraints

Constraints

Limitations on Public Access and Use

Access Constraints Directive

Access Constraints Text

Use Constraints

Attribution Statement

Metadata

Metadata

Publishing Body