Have you ever held your breath for as long as you could while swimming and then burst above the surface gasping for air? How long did you last under water? Probably nowhere near as long as a beaver can.
Beavers can hold their breath for up to 15 minutes! That’s a lot longer than us humans. Most people can hold their breath for about 30 seconds, although some people can hold it for a minute or even two. The world record is an astonishing 24 minutes and 3 seconds!
However, the world record holder was able to hold his breath for more than 24 minutes by using a technique called oxygen assist. With oxygen assist, people breathe in pure oxygen immediately prior to extended periods of not breathing. This allows a person's lungs to be filled with pure oxygen as they begin holding their breath.
Beavers don’t need to breathe pure oxygen before diving in the water. They are born with this ability. But as good as they are at staying under water for long periods, they aren't even close to the best at it. Elephant seals can hold their breathe for as long as two hours!
Aquatic and semiaquatic animals can hold their breath for so long because of several factors. First, when they dive into the water, they slow their heart rate and — obviously — stop breathing. Their bodies also change how blood flows, keeping it away from their arms and legs and concentrating blood flow around their brains, hearts and muscles.
These animals also have a type of protein called myoglobin, which attaches to oxygen in their muscles. Humans have myoglobin too, but not nearly as much as aquatic mammals do. The high levels of myoglobin in the animals’ muscle tissue give beavers and other aquatic mammals a larger supply of oxygen to use while under water, which lets them stay under for longer.
The discovery of myoglobin concentrations in diving mammals is recent by science standards. It was first was published in a study in June 2013 in the journal Science. The researchers who did the study hope it leads to more research into myoglobin and diving animals.
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