Acoustic Monitoring of Fish Behavioral Interactions with Tidal Energy Systems

Acoustic monitoring has emerged as a pivotal approach to elucidating how fish interact with tidal energy installations. By deploying a range of sonar and acoustic imaging instruments in high-energy tidal channels, researchers can observe fish presence, movement patterns and behavioural responses in conditions where optical methods fail. Typical systems include imaging sonars (acoustic cameras), multibeam echosounders and multifrequency echosounders, often integrated on fixed seabed platforms or autonomous vehicles. Data processing algorithms filter intense turbulence-induced backscatter and isolate biological targets, enabling detection, classification, tracking and quantification of individual fish and schools. These technologies reveal avoidance or attraction behaviours around turbine blades and support risk assessments for collision and habitat displacement. Acoustic monitoring thus informs turbine design, array configuration and regulatory decisions, contributing to sustainable development of tidal energy while safeguarding fish populations globally.

Research from Nature Portfolio

A recent study employing scaled laboratory experiments with vertical-axis turbines demonstrated that fish readily detect and avoid turbine wakes under varying flow discharges and confinement levels. Although individuals passed upstream and downstream, they spent significantly less time in the low-velocity, turbulent wake region, indicating a clear avoidance response. Reduced residence time near operating turbines suggests that properly designed devices pose minimal collision risk to small and medium-sized fish, supporting the case for deploying hydrokinetic turbines in rivers and estuaries with limited ecological impact.

Acoustic Monitoring of Fish Behavioral Interactions with Tidal Energy Systems publication trend

The graph below shows the total number of articles in acoustic monitoring of fish behavioral interactions with tidal energy systems across all publications each year (not limited to Nature Index journals).

Technical terms

Acoustic camera: A high-frequency imaging sonar that produces detailed, near-video-quality acoustic images of underwater scenes, enabling real-time detection and classification of fish and other targets in low-visibility conditions.

Multibeam echosounder: A sonar system that emits multiple acoustic beams across a wide swath to map the water column and detect targets by measuring backscatter intensity and range, often used for continuous monitoring around marine structures.

Hydrokinetic turbine: A device that extracts mechanical energy from flowing water in rivers, tidal straits or ocean currents, typically featuring rotating blades whose interactions with marine fauna are monitored for ecological impact.

Backscatter: The reflection of an emitted acoustic signal from objects or particles in the water, used to infer the presence, size and behaviour of fish and other marine organisms.

References

1. Observing fish interactions with marine energy turbines using acoustic cameras. Fish and Fisheries (2023).
2. Fish response to the presence of hydrokinetic turbines as a sustainable energy solution. Scientific Reports (2023).
3. Multisensor Acoustic Tracking of Fish and Seabird Behavior Around Tidal Turbine Structures in Scotland. IEEE Journal of Oceanic Engineering (2017).
4. A Self-Contained Subsea Platform for Acoustic Monitoring of the Environment Around Marine Renewable Energy Devices–Field Deployments at Wave and Tidal Energy Sites in Orkney, Scotland. IEEE Journal of Oceanic Engineering (2015).
5. A Probabilistic Model for Hydrokinetic Turbine Collision Risks: Exploring Impacts on Fish. PLOS ONE (2015).
6. Automatic active acoustic target detection in turbulent aquatic environments. Limnology and Oceanography Methods (2017).