How long dolphins underwater

Although still a matter of discussion, most researchers feel that in order to breathe, a dolphin or whale must be conscious and alert to recognize that its blowhole is at the surface. Humans, of course, can breathe while the conscious mind is asleep; our subconscious mechanisms have control of this involuntary system. But equipped with a voluntary respiratory system, whales and dolphins must keep part of the brain alert to trigger each breath. Other methods help marine mammals to hold their breath longer than other types of mammals can.

Marine mammals can take in more air with each breath, as their lungs are proportionately larger than those in humans. In addition, they exchange more air with each inhalation and exhalation. Their red blood cells also carry more oxygen.

And when diving, marine mammals' blood travels only to the parts of the body that need oxygen--the heart, the brain and the swimming muscles.

Digestion and any other processes have to wait. Finally, these animals have a higher tolerance for carbon dioxide CO 2. Their brains do not trigger a breathing response until the levels of CO 2 are much higher than what humans can tolerate. These mechanisms, part of the marine mammal diving response, are adaptations to living in an aquatic environment and help during the process of sleeping.

Cetaceans reduce the number of breaths they take during rest periods; a dolphin might average 8 to 12 breaths a minute when fairly active only to have their breathing rate drop to 3 to 7 per minute while resting. It is actually rare for a marine mammal to "drown," as they won't inhale underwater; but they do suffocate from a lack of air.

Being born underwater can cause problems for newborn whale and dolphin calves. It is the touch of air on the skin which triggers that first, crucial breath. And necropsies sometimes show that an animal never gets to the surface to take its first breath of air. The same problem can occur when an animal is caught in a fishing net. If unable to reach the surface, or if in a panic, the animal may dive deeper, where it will be unable to breathe and suffocate.

Obviously sleeping safely at sea can pose problems, but the marine mammal system has addressed them. If the left brain is sleeping, the right eye stays open and vice versa. So they always know when it's time to surface and breathe and when to get to the heck out of dodge. This is just amazing, I thought sleeping with one eye open was a myth!

But, dolphins proved us wrong. Just astonishing what mammals, including us can do. I think its very interesting that dolphins sleep with one eye open and one eye closed. I have to sleep with both my eyes shut. It would be very interesting to experience or watch a dolphin sleep. Another thing I think is cool is that dolphins can be underwater without breathing for about seven minutes. I can only be underwater without breathing for about seconds. Dolphins can't sleep on the surface with out swimming if they sleep with half of their brain awake they can still swim but, if they sleep on the surface they can sink and because they will not notice that they are sinking its like if you are asleep can you tell if you roll over on the bed no right ,so they can't tell either.

I think this is amazing because its cool how they sleep compared to humans. It would be cool to see this in real life.

Other dolphins will jostle a dolphin at risk in this way to keep him awake, and will hold the dolphin to the surface so that he can breathe. Helping other dolphins seems to be so strongly ingrained that that may be why dolphins sometimes come to the assistance of humans in trouble in the water. How long can dolphins hold their breath for underwater?