Why don’t seals drown?
They can time their dives to match their blood oxygen
FREE-DIVING IS a perilous sport. Divers, swimming underwater without oxygen tanks, frequently black out from low oxygen and put themselves at risk of drowning. Marine mammals such as seals, by contrast, can spend most of their lives below the surface without running such risks. A paper published in Science on March 20th explains why: seals can apparently sense how much oxygen they have in their blood and plan their actions accordingly.
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This article appeared in the Science & technology section of the print edition under the headline “Deep dives”
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