Unlike humans who can sleep through the night, dolphins must come up for air so their sleeping patterns are very different from ours. When dolphins sleep, they take turns resting one side of their brain at a time by closing the corresponding eye.
For example, the left eye closes when the right brain sleeps. Dolphins often sleep near the water’s surface, either floating still or swimming slowly. In shallow water, they might sleep on the ocean floor, rising to the surface regularly for air.
What Happens When a Dolphin Completely Loses Consciousness In Their Sleep?
If dolphins slept as deeply as we do, they’d drown due to a lack of oxygen. They must stay partially awake to keep one half of their brain alert to dangers in the water.
Why Do Dolphins Sleep With One Eye Open?
Dolphins sleep with just one eye open. They do this to stay aware of their surroundings and react quickly if needed. This also helps them detect predators, notice environmental changes, and come up for air when necessary.
Because only one brain hemisphere rests at a time, this sleep is called unihemispheric sleep. Dolphins aren’t the only creatures who sleep this way—other marine animals like seals, crocodiles, and whales do too.
