Research project: Impacts of low-head hydropower on freshwater fish migration

This field study focuses on a low-head hydropower installation comprising several structures including an Archimedes screw, Larinier fish pass, two elver passes and multiple weirs.  A range of fish species are tracked as they approach and pass the structure, using PIT and acoustic telemetry to investigate route choice and migration speed. Fine scale behavioural observations of fish as they pass through the site enables quantification of delay or rejection around the structures, as well as assessment of any damage and mortality through contact with the rotating screw. Data from a previous study of adult eel (Anguilla anguilla) migration in the same river prior to the hydropower installation will also enable ‘before and after' assessment of potential impacts on the migration of this critically endangered species.

This work will indicate the efficacy of low head hydropower and associated passage facilities at providing safe passage routes for multiple species and life-stages of migrating fish. Findings will provide valuable information for river managers that increasingly need to balance the surge in low-head hydropower with maintaining and improving free passage for all fish species.