To break the record for longest dive by a marine mammal, take a deep breath and jump in the water. Then don’t breathe in again for almost four hours.
Cuvier’s beaked whales (Ziphius cavirostris) are master divers. These creatures hold the record for deepest plunge by a marine mammal. One whale dived to depths of nearly 3,000 meters (almost 1.9 miles). This species also holds the record for the longest dives. In 2014, scientists documented one dive that lasted just over two hours. That whale stayed underwater for 137.5 minutes, setting a record.
Another Cuvier’s beaked whale has now shattered that record. It went 222 minutes, or three hours and 42 minutes, without coming up for air. Researchers reported this September 23 in the Journal of Experimental Biology.
To last so long underwater, the mammals may rely on large stores of oxygen and a slow metabolism. Once oxygen runs out, the animals may have the ability to tolerate a buildup of lactic acid in their muscles due to anaerobic (An-eh-ROH-bik) respiration. This is a method of generating energy that doesn’t rely on oxygen.
“These guys blow our expectations,” says Nicola Quick. She studies animal behavior at Duke University Marine Laboratory in Beaufort, N.C.
To better understand how the whales manage such long dives, the scientists looked to seals. Also marine mammals, seals can spend a long time underwater, too. Researchers have studied the diving habits of seals in the past. They can use that knowledge to learn about other animals. The researchers did some math based on a seal’s oxygen stores and diving time limits. That hinted that underwater whales should run out of oxygen after only about half an hour.
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Quick’s team then analyzed 3,680 dives by 23 whales. Seals can exceed their limit about 5 percent of the time. The team assumed that was true for Cuvier’s beaked whales, too. While most whale dives lasted around an hour, 5 percent exceeded about 78 minutes. That suggests that switching to anaerobic respiration takes more than twice as long for whales as had been thought.
The researchers expected to find that the whales spend more time at the surface recovering after long dives. However, the new team saw no clear pattern. “We know very little about [the whales] at all,” Quick says, “which is interesting and frustrating at once.”