Asked by: Robert Lee, Penzance
Even humans can survive underwater for a bit. The main problem is the lack of oxygen. Like us, turtles simply come up to breathe, although being cold-blooded they don’t use oxygen as quickly. To avoid lung pressure problems, deep-diving turtles have considerable oxygen stores in blood and tissues. Research in several species also shows various adaptions to low oxygen/high carbon dioxide levels, for example, better tolerance of acid blood.