Impulsive noise pollution in the Northeast Atlantic: Reported activity during 2015-2017.

Underwater noise pollution from impulsive sources (e.g. explosions, seismic airguns, percussive pile driving) can affect marine fauna through mortality, physical injury, auditory damage, physiological stress, acoustic masking, and behavioural responses. Given the potential for large-scale impact on marine ecosystems, some countries are now monitoring impulsive noise activity, coordinated internationally through Regional Seas Conventions. Here, we assess impulsive noise activity in the Northeast Atlantic reported during 2015-2017 to the first international impulsive noise register (INR), established in 2016 under the OSPAR Convention. Seismic airgun surveys were the dominant noise source (67%-83% of annual activity) and declined by 38% during 2015-2017. Reported pile driving activity increased 46%. Explosions and sonar/acoustic deterrent devices both had overall increases in reported activity. Some increases were attributable to more comprehensive reporting in later years. We discuss utilising the INR for risk assessment, target setting, and forward planning, and the implementation of similar systems in other regions.

Impacts of Underwater Noise on Marine Vertebrates: Project Introduction and First Results.

The project conducts application-oriented research on impacts of underwater noise on marine vertebrates in the North and Baltic Seas. In distinct subprojects, the hearing sensitivity of harbor porpoises and gray seals as well as the acoustic tolerance limit of harbor porpoises to impulsive noise from pile driving and stress reactions caused by anthropogenic noise is investigated. Animals are equipped with DTAGs capable of recording the actual surrounding noise field of free-swimming harbor porpoises and seals. Acoustic noise mapping including porpoise detectors in the Natura 2000 sites of the North and Baltic Seas will help to fully understand current noise impacts.