Publication Date
6-1-2021
Document Type
Article
Publication Title
Biology Open
Volume
10
Issue
6
DOI
10.1242/bio.058679
Abstract
Anthropogenic noise can alter marine mammal behaviour and physiology, but little is known about cetacean cardiovascular responses to exposures, despite evidence that acoustic stressors, such as naval sonars, may lead to decompression sickness. Here, we measured heart rate and movements of two trained harbour porpoises during controlled exposure to 6–9 kHz sonar-like sweeps and 40 kHz peak-frequency noise pulses, designed to evoke acoustic startle responses. The porpoises initially responded to the sonar sweep with intensified bradycardia despite unaltered behaviour/ movement, but habituated rapidly to the stimuli. In contrast, 40 kHz noise pulses consistently evoked rapid muscle flinches (indicative of startles), but no behavioural or heart rate changes. We conclude that the autonomous startle response appears decoupled from, or overridden by, cardiac regulation in diving porpoises, whereas certain novel stimuli may motivate oxygen-conserving cardiovascular measures. Such responses to sound exposure may contribute to gas mismanagement for deeper-diving cetaceans.
Funding Number
OISE – 1159123
Funding Sponsor
National Science Foundation
Keywords
Acoustic startle reflex, Exposure, Habituation, Sonar
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Department
Moss Landing Marine Laboratories
Recommended Citation
Siri L. Elmegaard, Birgitte I. McDonald, Jonas Teilmann, and Peter T. Madsen. "Heart rate and startle responses in diving, captive harbour porpoises (Phocoena phocoena) exposed to transient noise and sonar" Biology Open (2021). https://doi.org/10.1242/bio.058679
