D1230/001/01 - Bullhead Monitoring for the Dee Catchment, 2004

Subject Fish
Abstract Population data for the fish bullhead (Cottus gobio) collected in the River Dee Catchment since 2001 and additional quantitive and semi-quantitive survey data to assess bullhead abundance from 2004. Bullhead is listed under Annex II of the Habitat and Species Directive as a "species of community interest". Bullhead numbers have been declining across Europe in recent decades as a result of human activities. Bullhead is a designated feature on the River Dee and Bala Lake / Afon Dyfrdwy a Llyn Tegid Special Area of Conservation (SAC). Further information, including information on population structure is available in CCW Review of Consents Report no. 19.
Species Groups Bony Fish (Actinopterygii) [87]
Geographic Coverage/Site Name General: North East Wales
Geographic Coverage Notes The Dee catchment area, North Wales.
Dataset Owner Natural Resources Wales
Dataset Contact Barnaby Letheren
Date Range 2001 - 2004
Total Records 87
Restriction Details Standard Restrictions Only
Acknowledgements Cyfoeth Naturiol Cymru/Natural Resources Wales
Expand/Collapse Further Details
Original Title Bullhead Monitoring for the Dee Catchment, 2004
Temporal Coverage Notes 2001 - 2004
Data Storage Methods Published report. Excel spreadsheet, summary data in Recorder 2002 and MapInfo.
Purpose To assess bullhead abundances and population structure throughout the SAC area.
Capture Methods Historical data for 2001 - 2003: Data was collated from the North Wales Fisheries Monitoring Programme of 2001. A limited number of sites (approx 12) are fished on an annual basis to obtain information and detect trends within the fish populations and catches. Bullhead populations were also recorded as part of the Dee Stock Assessment Programme on a selection of sites in 2004 and as part of work on the Eel Monitoring Programme at 3 sites in the Dee Catchment for 2004. All sites were surveyed using the electric fishing equipment in accordance with protocols described in the Environment Agency - Electric Fishing Theory and Practice Manual (1988). Two methodologies were employed either quantitive temporal data for sites surveyed annually or semi-quantitive spatial data for sites surveyed every 5 years. Three fishing runs were used for quantitive surveys and one for semi-quantitive surveys.
Verification/Validation Procedures High confidence. Data collected by Environment Agency.
Data Collected by Environment Agency Wales
Dataset Category Category 03: Dataset originates from other trusted source
Dataset Status Dataset Complete
Data Entry Project Completion Date N/A
Date Imported 10/10/2013