Location
Groningen, The Netherlands
Event Website
http://fishpassage.umass.edu/
Start Date
24-6-2015 3:00 PM
End Date
24-6-2015 3:15 PM
Description
Abstract:
Co-location of hydropower turbine outfalls with fish pass entrances has been suggested as current best practice to optimise the attraction flows for the fish pass and to mitigate the perceived negative impacts of small run-of-river hydropower schemes. To test this a five year acoustic tracking study was instigated to monitor the installation of a low-head Archimedes screw turbine alongside an existing pool-traverse fish pass on Ruswarp Weir, at the tidal limit of the River Esk (England). The study tracked the behaviour of salmon and sea trout as they approached the weir and fish pass and determined the overall passage rate (% of tagged fish ascending the weir by any route), the attraction efficiency (% of tagged fish entering the pool below the fish pass) and the fish pass efficiency (% of tagged fish detected in the pool below the fish pass that ascended the weir via the pass). Over the five years (3 years pre and 2 years post) 138 sea trout and 18 salmon were tracked using acoustic tags with arrays of fixed and mobile hydrophones to determine large-scale behaviour in the tideway and in the approach to the fish pass (a pool-traverse pass, replaced by a Larinier pass during construction of the turbine). The study showed that following the co-location of the turbine and the construction of the Larinier pass there was a significant increase in the attraction efficiency (35% to 69%) and the overall passage rate (35% to 53%) but a significant reduction in fish pass efficiency (100% to 69%) for sea trout. These results support the concept of colocating outfalls to increase attraction efficiency whilst at the same time raise concerns that this also reduced the fish pass efficiency; perhaps causing a distraction and delay to migrants, with an associated increased risk of predation.
Session B8: Changes in Fish Passage Metrics Following the Co-Location of a Low-Head Hydropower Turbine with an Existing Fish Pass; Revealed by an Acoustic Tracking Study of Migratory Salmonids
Groningen, The Netherlands
Abstract:
Co-location of hydropower turbine outfalls with fish pass entrances has been suggested as current best practice to optimise the attraction flows for the fish pass and to mitigate the perceived negative impacts of small run-of-river hydropower schemes. To test this a five year acoustic tracking study was instigated to monitor the installation of a low-head Archimedes screw turbine alongside an existing pool-traverse fish pass on Ruswarp Weir, at the tidal limit of the River Esk (England). The study tracked the behaviour of salmon and sea trout as they approached the weir and fish pass and determined the overall passage rate (% of tagged fish ascending the weir by any route), the attraction efficiency (% of tagged fish entering the pool below the fish pass) and the fish pass efficiency (% of tagged fish detected in the pool below the fish pass that ascended the weir via the pass). Over the five years (3 years pre and 2 years post) 138 sea trout and 18 salmon were tracked using acoustic tags with arrays of fixed and mobile hydrophones to determine large-scale behaviour in the tideway and in the approach to the fish pass (a pool-traverse pass, replaced by a Larinier pass during construction of the turbine). The study showed that following the co-location of the turbine and the construction of the Larinier pass there was a significant increase in the attraction efficiency (35% to 69%) and the overall passage rate (35% to 53%) but a significant reduction in fish pass efficiency (100% to 69%) for sea trout. These results support the concept of colocating outfalls to increase attraction efficiency whilst at the same time raise concerns that this also reduced the fish pass efficiency; perhaps causing a distraction and delay to migrants, with an associated increased risk of predation.
https://scholarworks.umass.edu/fishpassage_conference/2015/June24/9
Comments
Presenting Author Bio: Jim’s 20 year career in fisheries began using acoustic and radio telemetry to monitor fish movement in impounded rivers. An early adopter and champion of split-beam acoustics and imaging sonar for fisheries monitoring, he has developed monitoring tools and techniques for fish passes and has a long association with technology based fish monitoring methods. Awarded the Winston Churchill Medal from HM Queen for international work on fish monitoring, he is a former Editor of FISH magazine and Vice-chair and Fellow of the Institute of Fisheries Management. Jim now manages a team of technical specialists and is responsible, among other things, for providing a fish passage advisory service for the Environment Agency and their delivery partners.