The reaction of narwhals to the loud noise from seismic air guns used in oil exploration involves a disruption of the normal physiological response to intense exercise as the animals try to escape the noise. The overall effect is a large increase in the energetic cost of diving while a paradoxically reduced heart rate alters the circulation of blood and oxygen.
source https://www.lifetechnology.com/blogs/life-technology-science-news/narwhals-show-physiological-disruption-in-response-to-seismic-survey-ship-noise
