How long can you hold your breath? Even your maximum effort cannot come close to the overwhelming power of the Cuvier beak whale superclus.
These whales have already sunk deeper and longer than any other mammal, but new research shows that their marathon dives may last even longer than previously thought.
Recently, scientists studied the data of thousands of whale dives, they found that one of these extreme divers held his breath for more than 3 hours, breaking a previously recorded record – also in the whale Cuvier (Your scrof) – more than an hour.
Equally intriguing was the ability of deep-sea whales to recover relatively quickly from their efforts. One whale rested for only 20 minutes after a 2-hour dive, hinting that even what appears to be an extreme dive (at least for us) may not be a big deal for the species, the researchers said in a new study.
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Cuvier whales with beaks, also known as goose beak whales, can grow up to 7 meters in length and weigh up to 6,800 pounds. (3080 kilograms), according to the National Atmosphere and Oceania Administration (NOAA). Mature men have two cone-shaped teeth protruding from the lower jaw, and their bodies are often clogged with long pale scratches, which are believed to be scars from mating over women, according to the Alaskan Department of Fish and Game.
Whales are found in deep ocean waters in most of the world, but because they spend very little time on the surface, they are extremely difficult to observe in the wild, said lead author Nicola Quick, a researcher at Duke Duke’s Marine Laboratory. Duke University School of the Environment in Durham, North Carolina.
“They spend 90% of their time underwater, at depths or in smaller dives,” Quick told Live Science. When whales begin to breathe infrequently, they emerge for an average of about 2 minutes before diving again, leaving marine scientists little time to detect whales, place a satellite location tracking tag to collect data or recover data from tags, he quickly explained.
“It’s like a blessing and a curse: No one knows much about whales with beaks, so there are a lot of questions! But then it’s very difficult to get data,” she said.
In the study, Quick and her colleagues examined more than 3,680 dives between 2014 and 2018 using 23 tagged whales in the waters off Cape Hatteras, North Carolina. Scientists have divided the dives into two categories: food (whales eat squid and deep-sea fish) and non-food. They found that during non-foraging dives, when animals did not actively hunt for prey, whales dropped to an average depth of 300 to 500 meters for an average of about 30 minutes. In comparison, the dives were deeper and longer, reaching a depth of about 1460 meters and lasting an average of about 60 minutes, the researchers said.
Although researchers don’t know for sure what whales do in the ocean depths when they’re not hunting, they could develop the ability to linger in deeper (and dark) waters to avoid predators such as killer whales that hunt visually, Fast said.
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Diving mammals can stay underwater after they deplete accumulated oxygen by switching to anaerobic respiration, which lactic acid accumulate in body tissues, contributing to muscle fatigue. Previous studies of other deep-sea mammal divers have shown that they perform about 95% of the dives before they need to switch to anaerobic respiration, according to the study. When the researchers applied this formula to their data, they estimated that Cuvier’s beaked whales could hold their breath for about 78 minutes before anaerobic respiration began.
And some whale dives were much, much longer than that.
Earlier, in 2014, another group of researchers reported a record dive of Cuvier whales with their beaks, which lasted 2 hours 17.5 minutes. However, when the authors of the new study examined the data from 2017, they found a pair of extreme dives made by one whale, which destroyed existing records. The first dive lasted 2 hours and 53 minutes, and this new record quickly surpassed an even longer dive by 3 hours and 42 minutes, according to the study.
“It goes against what we think mammals should do,” Quick said.
Even more surprising was the discovery that the recovery time of whales that dived deep and long was not necessarily longer than that of whales that performed shorter and shallow dives. Extreme loads are costly for most mammals, and they usually require a long period of rest and recovery. Data from thousands of whale dives show that these too long dives have pushed the whale’s endurance limit, “so we really expected that these long dives would increase recovery time,” Quick said.
Instead, the researchers found no clear pattern during whale rest. One whale was submerged for 78 minutes, after which it lasted almost 4 hours, during which it made smaller dives mixed with surface breaks. Another whale completed a 2-hour dive and resumed a deep dive for 20 minutes.
One possible explanation is that whales have metabolically untied the mechanisms that provide them with oxygen and eliminate muscle fatigue – even if they are tired after these extreme dives, Quick said.
On the other hand, “perhaps what we consider extreme for these guys, based on what we know at the moment, is simply not extreme for them,” she added.
The findings were published online today (September 23) Journal of Experimental Biology.
Originally published on Live Science.