Freshwater Bullhead Survey Data in Wales
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 three Special Areas of Conservation (SACs) in Wales: River Dee and Bala Lake / Afon Dyfrdwy a Llyn Tegid; River Wye / Afon Gwy; River Usk / Afon Wysg. This survey records the presence and populations of the freshwater fish, Bullhead (Cottus gobio), within the River Wye and River Usk SACs in south-east Wales. Currently data is available for all three Special Areas of Conservation (See survey metadata for further details).
Wales - Rivers Dee, Usk and Wye.
The purpose of this data capture was to monitor bullhead populations to assess whether Special Areas of Conservation (SAC) management adequately protects that species.
Relevant species abundance data was extracted from the overall spreadsheet supplied with the RoC Report. Where quantitative and semi-quantitative surveys were carried out on the same site at the same time then the semi-quantitative data has not been extracted (as this is a subset of the quantitative data). Historical data for 2001 - 2003: Data was collated from the North Wales Fisheries Monitoring Programme of 2001. A limited number of sites (approximately 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 quantitative temporal data for sites surveyed annually or semi-quantitative spatial data for sites surveyed every 5 years. Three fishing runs were used for quantitative surveys and one for semi-quantitative surveys.
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Metadata last updated on 2017-11-17 11:49:41.0