Assessment of salmon and bullhead populations in Welsh rivers
Pisces Conservation were asked to carry out a review and assessment of the status of salmon (Salmo salar) and bullhead (Cottus gobio) in 8 Welsh rivers designated as Special Areas of Conservation (SAC); the Dee, Usk, Wye, Eden, Gwyrfai, Teifi, Tywi and Cleddau. The purpose of the assessment was to collate all available information in order to gauge whether the rivers met the criteria for the SAC designations.
A wide range of data for each species and river were gathered, assessed and reviewed, including:
- Fishery catches and electric fishing data
- Historical records
- River flow data
- Water quality measurements
- River morphology & substrate
- Predatory and competing species
- Barriers such as dams and weirs
- Water abstraction and discharge
The core of the report's findings was a set of Favourable Conditions tables, setting out the criteria required of each river, and whether the river satisfied those criteria. Finally recommendations were made on the collection of data for future SAC condition assessments.