====== Deep-diving animals ======

Human divers need to resurface very slowly to avoid dangerous 'gas embolisms' which lead to  [[https://en.wikipedia.org/wiki/Decompression_sickness|decompression sickness]] (a.k.a. //The Bends//).

Deep-diving animals - e.g. whales, dolphins, turtles (and some birds) etc do not suffer the same problems (or very rarely do). There is currently no explanation.

A 2018 paper in //Proceedings of the Royal Society B// reviews the current research and suggest a possible mechanism.

>While exposure to high pressure is a common challenge among breath-hold divers, there is large variation in respiratory anatomy, function and capacity between genera and even species. The ultra-deep-diving feats of some marine mammals go beyond our current understanding of respiratory physiology and lung mechanics."\\ 
>//See ://  [[http://rspb.royalsocietypublishing.org/content/285/1877/20180482|'Pulmonary ventilation–perfusion mismatch: a novel hypothesis for how diving vertebrates may avoid the bends']]

Some birds - e.g. the [[https://en.wikipedia.org/wiki/Thick-billed_murre|Thick-billed_murre]] can dive as deep as 200m. On rapid resurfacing, they apparently suffer no ill effects.
A 1992 [[https://esajournals.onlinelibrary.wiley.com/doi/abs/10.2307/1938746|study]] published in the //ESA// journal suggested that such birds may have some special as-yet-unknown lung structure or chemical surfactant at work.


//Note: //Although not strictly 'diving', it's known that the //Nautilus// (mollusc)  can somehow withstand rapid pressure changes of  80 standard atmospheres (1,200 psi), remaining apparently unharmed when brought to the surface.