Marine mammals are uniquely adapted to dive to incredible depths. New research from Duke University Marine Laboratory documented a new dive record by a Cuvier's beaked whale, an elusive open ocean species. According to the study, published this week in the online Journal of Experimental Biology, one Cuvier's beaked whale remained underwater for 3 hours and 42 minutes. Researchers also recorded another dive by the same animal lasting nearly three hours.
Nicola Quick, a marine biologist at the Duke University Marine Lab, led the study. In an article from the university, she said, "Cuvier's beaked whales are extraordinary divers, but these dives far exceed anything we'd seen to date." According to the article, the new record is nearly seven times longer than what scientists thought these whales were capable of.
According to Duke University, this study's goal was to understand how Cuvier's beaked whales can dive to great depths (of up to 10,000 feet), stay submerged for great lengths of time, and then how their bodies recover from such strenuous dives. Previous estimates based on the whales' average size predicted that they could store enough oxygen to remain underwater for 33 minutes.
The research team tagged two dozen whales from 2014 and 2018 and gathered data on more than 3,600 dives. From this data, the team learned an average dive for a Cuvier's beaked whale lasts about 78 minutes before the animals "resort to anaerobic respiration."
In addition to the astounding dive durations that surpassed predictions, Duke University reports that the team was equally astounded by the varying recovery times that did not appear dependent upon on dive duration. According to the study, one whale began diving again only 20-minutes after a two-hour dive. One of the whales that dove for 78 minutes spent four hours making shallow dives before initiating yet another deep foraging dive.
Quick said that they expected higher recovery times after long dives, but "the fact that we didn't opens up many other questions." The team suggests that Cuvier's beaked whales may have "exceptionally low" metabolisms, more extensive oxygen stores, and the ability to withstand lactic acid buildup in their muscles. They hope that future research will unveil some of these mechanisms.
Quick also states that the record-breaking dives are probably not common for the species since "they probably pushed the very outer limit of the animal's physical capabilities." She suggests that a bountiful food patch or noise disturbance could be responsible for the animal remaining submerged longer than usual.
Sources: Duke--Nicholas School of the Environment, Journal of Experimental Biology