Blue Whales Respond to Anthropogenic Noise

• Main Authors: Melcón, Mariana L., Cummins, Amanda J., Kerosky, Sara M., Roche, Lauren K., Wiggins, Sean M., Hildebrand, John A.
• Other Authors: Naval Postgraduate School
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: PLOS 2012
• Subjects: Sonar; Blue whales; Foraging; Ships; Killer whales; Bioacoustics; Humpback whales; Vocalization; Pacific; Blue whale
• Online Access: https://hdl.handle.net/10945/66230

The article of record as published may be found at https://doi.org/10.1371/journal.pone.0032681 Anthropogenic noise may significantly impact exposed marine mammals. This work studied the vocalization response of endangered blue whales to anthropogenic noise sources in the mid-frequency range using passive acoustic monitoring in the Southern California Bight. Blue whales were less likely to produce calls when mid-frequency active sonar was present. This reduction was more pronounced when the sonar source was closer to the animal, at higher sound levels. The animals were equally likely to stop calling at any time of day, showing no diel pattern in their sensitivity to sonar. Conversely, the likelihood of whales emitting calls increased when ship sounds were nearby. Whales did not show a differential response to ship noise as a function of the time of the day either. These results demonstrate that anthropogenic noise, even at frequencies well above the blue whales' sound production range, has a strong probability of eliciting changes in vocal behavior. The long-term implications of disruption in call production to blue whale foraging and other behaviors are currently not well understood. Naval Postgraduate School Chief of Naval Operations N45 Pacific Fleet