What dramatic change occurs in the heart rate of seals during a dive to conserve oxygen for vital organs?

Answer

It plummets, sometimes as low as 7 beats per minute

During a dive, the heart rate plummets dramatically, sometimes dropping from around 70 beats per minute down to as low as 7 bpm, to conserve oxygen.

What dramatic change occurs in the heart rate of seals during a dive to conserve oxygen for vital organs?
mammaladaptationPinnipedFur Seal