I was wondering, why can't humans live under water like whales or seals? If whales can live underwater, and they're mammals, why can't we?
closed as off-topic by David, terdon, Bryan Krause♦, Charles, Amory Jan 3 '18 at 14:04
This question appears to be off-topic. The users who voted to close gave this specific reason:
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Kooyman et al. (1981) Annu Rev Physiol 43: 343-356; emphasis mine:
What explanation can we offer for the known capability of some marine mammals, such as Weddell seals and sperm whales, to remain submerged for over an hour?
(a) a large total oxygen store relative to body size, and
(b) parsimonious use of blood oxygen due to the lowered energy requirements of various organs.
During long dives, some organs deplete their oxygen stores, become predominately dependent on anaerobic metabolism, and build up large quantities of lactate. The result is a degree of fatigue that leaves the animal incapable of further intense diving activities for some time.