Fish Passage Engineering and Biological Responses

Anthropogenic barriers such as dams and weirs fragment riverine habitats and impede the migratory pathways of fish, with consequences for population connectivity, genetic diversity and ecosystem function. Fish passage engineering encompasses a spectrum of structural and operational solutions—ranging from pool‐and‐weir and vertical‐slot fishways to bypass channels and turbine screening systems—designed to facilitate upstream and downstream movement. Effective design requires integration of hydrodynamic principles, particularly flow velocity profiles, turbulence patterns and attraction currents, to provide navigable routes that align with species‐specific swimming capabilities and behavioural cues. Advances in sensor technologies, three‐dimensional flow modelling and telemetry have enhanced our understanding of the fine‐scale interactions between fish and engineered structures, revealing critical thresholds of shear stress, pressure fluctuations and delay times. Concurrently, ecological research has emphasised the importance of adaptive management, selective passage to exclude invasive species, and the evaluation of post‐passage sublethal impacts. Cross‐disciplinary collaboration and standardised methodologies are now recognised as essential to optimise fishway performance on a global scale, especially in regions undergoing rapid hydropower development and conservation of diadromous and resident fish communities.

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Fish Passage Engineering and Biological Responses publication trend

The graph below shows the total number of articles in fish passage engineering and biological responses across all publications each year (not limited to Nature Index journals).

Technical terms

Fishway: Engineered channel or structure allowing fish to bypass barriers such as weirs or turbines.

Acoustic telemetry: Method of tracking fish movement using sound‐emitting tags and underwater receivers.

Computational fluid dynamics: Numerical modelling technique for simulating fluid flow and turbulence around structures.

Turbulence kinetic energy: Measure of the intensity of turbulent flow fluctuations affecting fish swimming and navigation.

References

1. Safe passage for fish: The case for in-stream turbines. Renewable and Sustainable Energy Reviews (2023).
2. Swimming behaviour of Atlantic salmon kelts migrating past a hydropower plant dam: Effects of hydraulics and dam operations. The Science of The Total Environment (2024).
3. The future of fish passage science, engineering, and practice. Fish and Fisheries (2017).
4. Selective fragmentation and the management of fish movement across anthropogenic barriers. Ecological Applications (2018).
5. Fish responses to flow velocity and turbulence in relation to size, sex and parasite load. Journal of The Royal Society Interface (2014).
6. Optimizing attraction flow for upstream fish passage at a hydropower dam employing 3D Detached-Eddy Simulation. Ecological Engineering (2017).
7. Evaluation of external fish injury caused by hydropower plants based on a novel field‐based protocol. Fisheries Management and Ecology (2017).
8. Design and implementation of a new autonomous sensor fish to support advanced hydropower development. Review of Scientific Instruments (2014).