Study confirms Cuvier's beaked whale is world's deepest-diving mammal

Feb. 7 (UPI) -- Scientists have confirmed Cuvier's beaked whale is the world's deepest-diving mammal.

Biologists knew the beaked whale species dove to ear-popping depths, but the new Duke University-led study offered the first in-depth documentation of the species' diving behavior in the Atlantic.

Because the elusive whales spend so little time at the surface and rarely venture close to shore, studying their behavior is difficult. Researchers were able to tag several Cuvier's beaked whale off the coast of Cape Hatteras, N.C. The satellite tags recorded 3,242 hours of behavioral data from 5,926 dives.

"They typically only spend about two minutes at the surface between dives," Jeanne Shearer, a doctoral student in ecology at Duke University, said in a news release. "It's amazing that they can dive to such depths, withstand the pressure, and be down there that long, with such brief recovery times."

Scientists have previously tracked the dives of Cuvier's beaked whales in the Pacific, Mediterranean and Caribbean, but studies suggest beaked whale populations exhibit distinct diving patterns.

The new data showed the whales' deepest dives extend more than 4,500 feet beneath the ocean surface. Deep dives can last two to three hours. The whales dive continuously, with deep dives followed by a few shorter dives, averaging 1,000 feet.

"Cuvier's beaked whales are only half the size of the sperm whale," Shearer said. "Their dives push the limits of mammalian physiology, but we still don't know how they're able to behave this way."

Shearer and her colleagues published the results of their study this week in the journal Royal Society Open Science.

Better understanding the behavior and movement patterns of marine mammals can help researchers more accurately predict how sonar systems and shaping traffic will impact vulnerable species.

"These animals are fascinating and there is so much we still don't know about their behavior and physiology," Shearer said. "They are the world's deepest mammalian divers, but we don't yet understand how they dive to such extremes."