Barbel acoustic tagging and tracking

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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 m, are increasingly recognised as a major global threat to freshwater fish diversity.

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This project, focussed on the River Teme in the Severn catchment (western England), investigated the ecological consequences for freshwater fishes of river regulation schemes that are designed to deliver enhanced ecosystem services. The European barbel (Barbus barbus) was used as its focal species, given its propensity for long-distance freshwater migrations that make it highly sensitivity to disturbance.

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Acoustic tagging and telemetry were utilised to determine the longitudinal connectivity of the study rivers for barbel, through assessment of their daily, seasonal and annual movements. Twenty-two barbel were captured 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 were located along the river length, recording pings from the transmitters; data were then periodically downloaded and fish movement patterns were analysed. Mobile tracking was also used to determine specific spawning and feeding locations of tagged fish.