Porpoises Avoid Piling Noise Across 14 Km Zone
A 5.5-month North Sea study at an offshore wind farm sets a planning benchmark for marine mammal disturbance.
Updated on Nov. 5, 2026 in Environmental
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A study of the Dogger Bank C offshore wind farm in the North Sea used 27 passive acoustic monitoring moorings over 5.5 months to measure how harbor porpoises respond to pile driving. The research is observational field work rather than a product or deployed technology, and it estimates an average effective deterrence range of 14.4 km (roughly nine miles) for unmitigated piling.
Why it matters
Offshore wind construction depends on accurate estimates of how far marine mammals will avoid pile-driving noise, because that distance sets the area where animals are displaced. As offshore wind expands, these disturbance estimates will feed directly into conservation planning for the sites.
Passive acoustic monitoring recorded porpoise echolocation clicks continuously across depths over 5.5 months, yielding an average effective deterrence range of 14.4 km for unmitigated piling. The stub reports that bubble curtains can greatly reduce the deterrence zone, though it gives no figure for that reduction.
The players
Dogger Bank C offshore wind farm
An offshore wind installation in the North Sea that served as the site of the porpoise monitoring study.
The details
Researchers placed 27 passive acoustic monitoring moorings across multiple depth zones and around the piling location, recording echolocation clicks continuously to capture when harbor porpoises were present before and after each construction event. Porpoise activity was lowest near active hammers and rose with distance, with the strongest responses closest to construction and a sharp decline within roughly the first ten kilometers. Effects typically dissolved within 24 hours of hammer strikes, and longer piling sessions were more likely to produce a response.
Timeline
Monitoring ran for 5.5 months at the Dogger Bank C offshore wind farm.
Porpoise avoidance effects typically dissolved within 24 hours following hammer strikes.
The Tech Race
The Dogger Bank C monitoring extends the empirical record on porpoise avoidance by pairing a 14.4 km deterrence estimate with Scottish monopile data showing equivalent avoidance thresholds. The stub does not name a competing research program or product roadmap in this area.
The findings bear on how offshore wind projects plan pile-driving schedules and mitigation around marine mammals, since the deterrence range sets the area where animals will be displaced. The stub does not state any availability or timeline for changes to current construction practice.
The takeaway
Offshore wind developers and conservation planners will need the 14.4 km average deterrence range when estimating how far porpoises will be displaced. Watch for follow-up research on how these responses vary in other environments.
Further reading
For more on the environmental side of this work, browse our Environmental coverage.
Source note: This article includes information reported by Ecoportal.
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