Listening to Nature: How Environmental Acoustics Enhances Offshore Wind Development

Estimated reading time: 4 minutes

Offshore wind projects are increasingly turning to environmental acoustics to understand how marine life responds to human activity at sea. By recording and analysing underwater sounds, researchers are gaining critical insights into biodiversity, behaviour, and ecosystem changes.

Environmental acoustics combines two research fields—bioacoustics and ecoacoustics. Bioacoustics studies how living organisms produce and use sound, while ecoacoustics examines both natural and human-made sounds within ecosystems. Together, these methods provide a clearer picture of how marine life interacts with offshore wind farms.

Using passive acoustic monitoring (PAM), hydrophones capture a wide range of underwater sounds over extended periods. Unlike traditional surveys that often rely on physical sampling, PAM is non-invasive and continuous, producing long-term data on species presence, migration, and spawning activity. This approach also makes it possible to study nocturnal or elusive animals that are otherwise difficult to monitor.

The offshore wind sector faces two significant noise-related challenges. First, the industry is expanding rapidly. The Global Wind Energy Council reports that 8 GW of new offshore wind capacity was installed in 2024, raising the global total to 83 GW. With growth expected to continue at around 25% annually through 2030, construction and operation noise will remain an environmental consideration.

Second, the ocean is already a noisy place. Over the past 70 years, noise levels have climbed due to international shipping and industrial activities. For species such as whales, dolphins, and fish that rely heavily on sound for communication, feeding, and navigation, the increase in background noise presents real risks.

At the same time, acoustic technology has advanced significantly. The cost of underwater recorders has dropped, frequency ranges have expanded, and machine learning now accelerates species identification. These improvements make it possible to deploy environmental acoustics more widely in offshore wind projects.

While marine mammals remain a focus, researchers are expanding acoustic monitoring to fish and even invertebrates. Work led by Di Iorio et al. (2021) involved 27 coastal sampling sites over nearly 2,000 kilometres, showing how acoustic biodiversity can reveal large-scale ecosystem dynamics.

Fish species such as Atlantic cod are particularly relevant. Cod produce low-frequency sounds during spawning, making PAM a reliable tool to monitor breeding grounds. In Massachusetts Bay, long-term acoustic monitoring has been used to track cod spawning aggregations, providing essential data for fisheries management and offshore development planning.

Studies reviewed by Bolgan (2025) highlight the evolution of fish acoustics research from single-species studies to broader ecosystem-level monitoring. Today, ecoacoustics is being applied to track fish communities across coastal zones, deep-sea canyons, and areas influenced by marine energy infrastructure.

Environmental acoustics is now being embedded directly into offshore metocean campaigns. SEAWATCH® services, for example, integrate acoustic data collection with wind and wave measurements, eliminating the need for separate surveys. These systems also include ambient noise characterisation, enabling developers to assess both biological and human-made sounds in one deployment.

Collaboration is also key. Video analysis of birdlife, carried out with partners such as Spoor, is often combined with acoustics to give a broader view of how offshore projects influence ecosystems. Multi-sensor platforms are being trialled to capture currents, fish shoals, diving birds, and marine mammal activity in parallel, providing developers with a more comprehensive environmental dataset.

Future developments point to faster, cheaper, and more precise monitoring. On-edge analytics reduce the need to transmit vast amounts of data, extending hydrophone battery life. Real-time monitoring is becoming feasible, and machine learning continues to refine species detection.

Research institutions such as the Woods Hole Oceanographic Institute have also shown that reef-forming species like corals and oysters produce distinctive sounds linked to reef health. Playing recordings of healthy reefs has even been used to attract larvae to degraded habitats, suggesting a role for acoustic enrichment in restoration.

As offshore wind expands, environmental acoustics is proving to be an essential tool for balancing energy development with marine conservation. From monitoring cod spawning to characterising reef ecosystems, sound is helping scientists and developers better understand life beneath the waves.