Impact of Archimedes Screw Turbines on fish migration

Archimedes Screw Turbines are one type of small-scale hydropower widely regarded as “fish friendly” due their slow rotation speeds and small pressure fluctuations. However, information on indirect (second order) effects, such as delay to fish migration because of avoidance behaviour in response to acoustic and/or hydrodynamic conditions encountered, is lacking. Delay can compromise the populations of migratory fishes in numerous ways, including through elevated predation risk as fish accumulate at engineering structures. Using telemetry and dual frequency imaging sonar (e.g. DIDSON and ARIS), research at ICER is assessing the indirect effects of these turbines on fish.

For a community of coarse fish and European eel, milling and rejection / startle behaviour at the intake and tailrace of an Archimedes Screw Turbine was quantified. Despite some delay to downstream migrating eel, the turbine did provide a route of passage, with no immediate mortality or effect on subsequent migration.

Further work will assess route choice and delay to downstream migrating sea trout at an Archimedes Screw Turbine and associated weir. The turbines at the study site (Totnes on the River Dart, England) regulate the flow of water over the weir, providing an opportunity to assess fish migration with the turbines on and off.

Research on this topic has been funded by the Environment Agency (England), Natural Environment Research Council (NERC), the Engineering Physical Sciences Research Council (EPSRC), Fishtek Consulting, and the University of Southampton.

 

Media:

Archimedes screw turbines installed on a low-head weir in Southern England

Intake of an Archimedes screw turbine, a location which may delay downstream migrating fish

Sea trout smolt caught a few kilometres upstream of the Archimedes screw turbine

Publications:

Piper, A.T., Rosewarne, P.J., Wright, R.M. & Kemp, P.S. (2018). The impact of an Archimedes screw hydropower turbine on fish migration in a lowland river. Ecological Engineering 118: 31-42.

 

People:

James Miles

Dr Adam Piper

Prof Paul Kemp