Try something right now: hold your breath for 5 seconds. Probably easy, right? Now, take a deep breath and double it: hold your breath for 10 seconds. Then 20. If you practice holding your breath a ...

A pod of narwhals in Scoresby Sound, East Greenland, where the study took place. (Photo by C. Egevang) A large male narwhal raises his tusk as he catches his breath before diving in Scoresby Sound.

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 ...