Impacts of Substrate-Borne Vibrations from Pile Driving in a Benthic Marine Invertebrate

Many anthropogenic activities in the ocean involve direct contact with the seabed. These benthic interactions can potentially be harmful to marine fauna. For example, pile driving is commonly used for coastal and offshore constructions, including wind farms that overlap with vital marine habitats. The sound from pile driving is a major pollutant of international concern, although studies on substrate-borne vibrations arising from these activities are scarce, particularly those which address impacts to key benthic invertebrates. In a field-based study, the impacts of substrate-borne vibrations from pile driving were quantified on the giant scallop (Placopecten magellanicus), an ecologically and commercially important bivalve. Behavioral responses of tagged scallops to pile driving were assessed at two spatial scales (< 10 and 50 m from the source). Pile driving induced valve closures in scallops at substrate-borne vibration levels similar to those measured hundreds of meters from wind turbine constructions. These responses could have long-term energetic consequences on scallops, rending them more vulnerable to predation. The results suggest offshore wind farm constructions have the potential to impact scallop populations.