Editing Sea turtle (section)

=== Diving physiology ===
{{see also|Physiology of underwater diving#Aquatic reptiles}}
Sea turtles are air-breathing reptiles that have lungs, so they regularly surface to breathe. Sea turtles spend a majority of their time underwater, so they must be able to hold their breath for long periods.<ref name=":8" /> Dive duration largely depends on activity. A foraging sea turtle may typically spend 5–40 minutes underwater<ref name=":8">{{Cite journal|title = Voluntary diving metabolism and ventilation in the loggerhead sea turtle|journal = Journal of Experimental Marine Biology and Ecology|date = 1991-05-16|pages = 287–296|volume = 147|issue = 2|doi = 10.1016/0022-0981(91)90187-2|first1 = Molly E.|last1 = Lutcavage|first2 = Peter L.|last2 = Lutz|doi-access = free| bibcode=1991JEMBE.147..287L }}</ref> while a sleeping sea turtle can remain underwater for 4–7 hours.<ref>{{cite web|title = Information About Sea Turtles: Frequently Asked Questions |url = http://www.conserveturtles.org/seaturtleinformation.php?page=seaturtle-faq#14 |publisher = Sea Turtle Conservancy|access-date = 2015-10-15}}</ref><ref name=":9">{{Cite journal|title = First records of dive durations for a hibernating sea turtle|journal = Biology Letters|date = 2005-03-22|issn = 1744-9561|pmc = 1629053|pmid = 17148134|pages = 82–86|volume = 1|issue = 1|doi = 10.1098/rsbl.2004.0250|first1 = Sandra|last1 = Hochscheid|first2 = Flegra|last2 = Bentivegna|first3 = Graeme C.|last3 = Hays}}</ref> Remarkably, sea turtle respiration remains [[Cellular respiration|aerobic]] for the vast majority of voluntary dive time.<ref name=":8" /><ref name=":9" /> When a sea turtle is forcibly submerged (e.g. entangled in a trawl net) its diving endurance is substantially reduced, so it is more susceptible to drowning.<ref name=":8" />

When surfacing to breathe, a sea turtle can quickly refill its lungs with a single explosive exhalation and rapid inhalation. Their large lungs permit rapid exchange of oxygen and avoid trapping gases during deep dives.

[[Cold-stunning]] is a phenomenon that occurs when sea turtles enter cold ocean water ({{Convert|45|–|50|F|abbr=on|order=flip}}), which causes the turtles to float to the surface and therefore makes it impossible for them to swim.<ref>Spotila, J. R. (2004). ''Sea Turtles: A Complete Guide to Their Biology, Behavior, and Conservation''. Baltimore: Johns Hopkins University Press. {{isbn|978-0801880070}}</ref>