Summary
The study tested the vocalization response of harbor porpoises (Phocoena phocoena) to two different acoustic pingers, the AQUAmark 100 (20-160 kHz) and the AQUAmark 300 (10 kHz). Trials in Scotland and Denmark found that the AQUAmark 100 resulted in a significant reduction of porpoise vocalizations at 0,200, and 400 meters distance from the pingers. The vocalization behavior reveal no signs of habituation. Studies of the AQUAmark 300 resulted in a significant reduction of vocalizations at 0m and no significant reduction at 300m. Additionally, at one station, habituation effects were found.