(CN) — It would be fair to say the elusive Cuvier’s beaked whale seems shy. The torpedo-shaped mammals surface for just two minutes at a time and then head back down into the deep.
But a group of researchers say they have timed one record-breaking whale dive at 3 hours and 42 minutes, publishing their findings in the Journal of Experimental Biology, but the team was also left a bit baffled by what they found.
Cuvier’s beaked whales or “goose-beaked whales” because of their curved snouts, can dive for incredibly long periods of time to forage for food, avoid predators or to escape the surface world.
Researchers measured 3,680 dives by 23 whales tagged with satellite links on their fins to determine the duration of their dives. Just like dolphins, whales breathe air into their lungs and cannot breathe underwater.
Based on the Cuvier’s beaked whale’s body, researchers calculate the creatures should only be able to submerge for about 33 minutes before their oxygen runs out and they resort to anaerobic respiration, which is when the body burns or consumes other elements for respiration.
But Cuvier’s beaked whales managed to throw a curveball at the research team who observed whales off Cape Hatteras, North Carolina, as they observed dives that ranged from 33 minutes to 2 hours and 13 minutes, according to the study.
Most other mammals surface before their oxygen supply runs out during a dive and researchers found that if the same were true for the whales they could stay below for just 77 minutes.
“It really did surprise us that these animals are able to go so far beyond what predictions suggest their diving limits should be,” said research scientist Dr. Nicola Quick at the Duke Marine Lab in a statement.
Then there was the dive that lasted 3 hours and 42 minutes in 2017 and another that was almost 3 hours, according to the study authors.
“We didn’t believe it at first; these are mammals after all, and any mammal spending that long under water just seemed incredible.”
One theory is the whales have larger than usual oxygen storage in their bodies and an incredibly low metabolism that allow them to hold out against the stinging sensation that befalls anyone who is short on breath after a run or grueling exercise.
That lactic acid tends to build up in the muscles, but for the whales their long dives don’t seem bothered by the sensation says the study authors.
There are 23 species of beaked whales, according to Quick, and researchers know very little about them even though they’re a large group of mammals.
“Understanding their diving behavior enables us to start to understand how these animals are adapted to forage in deep water environments and to look at how human impacts may affect their behavior,” Quick said in an interview.
Other questions remain even after this study, like what’s the whale’s diving metabolic rate, how do they deal with by-products of metabolism, what’s their true oxygen storage capabilities and how do they dive for so long while actively foraging and echolocating at depth, Quick said.
Recovery times also varied for the whales. Some whales went right back to diving within 20 minutes of a 2-hour dive, while another whale observed took a 4-hour rest after a 78-minute dive.
“Going into the study, we thought we would see a pattern of increased recovery time after a long dive,” Quick said in a statement accompanying the study. “The fact that we didn’t opens up many other questions.”
Quick said the long dives could be explained by a healthy food batch that the whales ran into during a dive, or some threat or some type of noise intrigued or bothered them.
Quick was accompanied by William Cioffi, Jeanne Shearer, Andrew Read, Daniel Webster from the Cascadia Research Collective along with Andreas Fahlman from Fundacion Oceanografic de la Comunitat in Valencia, Spain.
Quick did not immediately respond to questions on the study’s findings.