Healthy oyster reefs produce a distinct underwater soundscape. The crackling and clicking of shrimp, fish and other reef organisms can serve as a natural signal for larvae searching for suitable habitat. International research suggests that oyster larvae respond to these acoustic cues. Within the Nature Regeneration North Sea program, this pilot project tested whether replaying recorded North Sea reef sound offshore could help stimulate oyster settlement and support reef recovery.
Flat oyster reefs once covered large parts of the Dutch North Sea but have disappeared due to overfishing, habitat degradation and disease. Although restoration efforts are ongoing, larval settlement remains a key bottleneck. The objective of this project was therefore twofold: to develop and validate a prototype offshore underwater loudspeaker that can operate under North Sea conditions, and to assess whether replayed reef sound increases oyster settlement compared to a silent reference location.
