OPTIMISING FISH PASS DESIGN FOR EUROPEAN EEL: FLUME-BASED TRIALS

Collaborators: Environment Agency
Location: Institute of Zoology

River infrastructure such as weirs, dams, hydropower facilities, pumping stations and tide gates disrupt flow connectivity and may restrict or prevent fish accessing the habitats required for completion of their lifecycle. The critically endangered European eel is a commercially and ecologically important catadromous species for which there are strong legislative drivers to improve passage at barriers and water offtakes, including The Eels (England and Wales) Regulation 2009. A wide range of potential barrier mitigation solutions are offered commercially to water managers, but robust tests of their efficacy under the full range of operating scenarios are lacking for most and there are concerns about the operating efficiency of some current installations. Fish passage technologies may be very costly, hence research is urgently needed to underpin management decisions to ensure that mitigation measures are fit for purpose and cost-effective.

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ZSL, in collaboration with our Environment Agency partners, are using the information gathered from good and bad real-world examples of pass installations as a foundation for developing better solutions. Flume-based studies at the newly renovated Institute of Zoology animal research facilities are enabling us to both optimise existing eel pass designs, and to try out some new promising concepts.