Barbel acoustic tagging and tracking (2015-2016)
Regulation of rivers for the purposes of flood defence, hydropower generation and navigation has profound physical and ecological impacts through disruptions to hydrology, natural functioning and connectivity. Whilst river regulatory schemes provide major ecosystem services for societal benefit, the resultant habitat disruption, including blockages to fish migration and physical changes to channel form, are increasingly recognised as a major global threat to freshwater fish diversity.
This project, focussing on the River Teme in the Severn catchment (western England) is investigating the ecological consequences for freshwater fishes of river regulation schemes that are designed to deliver enhanced ecosystem services. The European barbel (Barbus barbus) is used as its focal species, given its propensity for long-distance freshwater migrations that make it highly sensitivity to disturbance.
Acoustic tagging and telemetry are being utilised to determine the longitudinal connectivity of the study rivers for B. barbus, through assessment of their daily, seasonal and annual movements. Twenty-two barbel were captured in September 2015 from a mixture of angling and electric fishing. These fish were anaesthetised and had acoustic transmitters internally fitted. After recovery the fish were returned to the same stretch of water from which they were captured. An array of 14 acoustic receivers are located along the river length, recording pings from the transmitters; data are then periodically downloaded and fish movement patterns are analysed. Mobile tracking will be also used during 2016 to determine specific spawning and feeding locations of tagged fish.