Caring for Stranded Marine Animals
                                              Donate Now!

How Do Whales Breathe?


Because whales live in the ocean, many people think they are fish. But do you know that whales and dolphins are not fish? They are mammals. People are mammals too. Mammals are the group of animals that breath air using lungs, give birth to live young (rather than laying eggs), and feed their young with mother’s milk. All animals, including people, need oxygen, a chemical found in the air and in water. Fish use their gills to take oxygen from the water that they live in. But people get the oxygen we need by breathing air, using our lungs. Whales and dolphins use their lungs to breathe air also.

That’s one reasons why they come to the surface of the ocean. Sometimes they lie right at the surface of the water, with just a part of their back sticking out. Look closely at a picture of a whale or dolphin; can you see a nose on the whale? You can’t, because whales don’t have noses like you and me. Instead they have a hole – called a “blow hole” – on top of their heads. Sometimes when a whale breathes air out of its blow hole, it shows up as a spray or mist – called a “spout” – that can be seen many miles away. Blow holes are surrounded by muscles that keep the hole closed when the whale or dolphin is under water and open it when the animal is at the surface and needs to breathe.

In fact, some of the animals have two blow holes next to each other and others have only one. So when you see a picture of a whale, see if you can tell the difference. Pilot whales and dolphins have one blow hole; humpbacks, minkes and right whales have two.


  1. Hi Joey.
    Here’s a great article from Scientific American that explains this “half sleep” better than I ever could!
    Thanks for your question!

  2. Im confused on the whole “whales rest half their brain at a time” can you explain to me how they do that?

  3. Hi Rose.
    Despite their large size, a whale can exhale and inhale in less than a few seconds! And, they exchange 90% of the air in their lungs when they do so! Often when they are diving more deeply, they will surface and breathe several times over the course of a few minutes before going under again for a longer dive. Thanks for your Question!

  4. Hi Kathy, thanks for the informative post. Given how huge whales are, how long do you suppose they have to stay on the surface of the water to take in enough oxygen to survive under water?

  5. thanks

  6. Hi Astaria.
    Some whales rest half their brain at a time. Another strategy scientists have found is that sometimes whales will take short naps between breaths. I would suggest this is both a physical and behavioral adaptation. Thanks for your question!

Leave a Comment

Your email address will not be published. Required fields are marked *