DEC 01, 2019 7:11 AM PST

Blue Whales Exhibit 'Extremely Low' Heart Rates When Performing Deep Dives

WRITTEN BY: Anthony Bouchard

Blue whales have a reputation for being massive, and as far as we know, they’re the largest living animal in existence today. Perhaps unsurprisingly, this means that blue whales’ hearts are massive too, and they work incredibly hard to keep blood pumping through the marine mammal’s enormous body.

A conceptual image of a blue whale.

Image Credit: Pixabay

Like most marine mammals, blue whales often go for deep dives below the ocean’s surface in search of food, and this makes conserving oxygen very important. In most cases, marine mammals’ heart rates slow down during these critical deep-diving moments, helping to limit the animal’s blood-oxygen expenditure and enable longer deep dives. But while monitoring one blue whale’s heart rate during deep dives, researchers were particularly fascinated to learn just how low a blue whale’s heart rate can go. Their findings are now published in the journal Proceedings of the National Academy of Sciences (PNAS).

The data, captured with the assistance of a small, but effective GPS-enabled suction cup-based electrode, revealed that a deep-diving blue whale’s heart rate can slow down to as little as two beats per minute. At the highest end of the scale, its heart thumped as rapidly as 37 beats per minute on a deep dive, but on average, it rested between four and eight-and-a-half beats per minute during the deepest part of a deep dive.

Related: Blue whales are good at remembering prey hotspots

The electrode was designed to be non-invasive. The suction cup didn’t harm the blue whale, and as such, it didn’t impact the animal’s stress levels in any way. The findings were particularly astonishing because researchers initially thought that a blue whale’s heart rate would sit at around 11 beats per minute on a deep dive. Learning that the estimations were this far off paints a very different picture of our understanding of blue whales and their bodily limits.

The research also showed that a blue whale’s heart rate can shift somewhat rapidly – sometimes in the span of just one or two minutes. Moreover, these heart rate fluctuations occurred continuously as the blue whale performed various tasks, be it casually swimming along at these depths or actually feeding.

As it would seem, blue whales may push their bodies to the limit when in search of food. The findings also raise some interesting questions about how blue whales’ nervous systems work and whether other whale species exhibit the same or similar heart rate fluctuations while performing the same or similar tasks.

“Sperm whales, beaked whales — some of those species can dive for an hour or more,” elucidated Dr. Jeremy Goldbogen, the lead author of the blue whale deep-diving heart rate study. “We would like to understand what their hearts are doing.”

Related: Most blue whales appear to be 'right-handed'

It should be interesting to see if future research shows similar behavior with other blue whales, and perhaps more importantly, with other whale species. Only time will tell…

Source: New York Times, PNAS

About the Author
  • Fascinated by scientific discoveries and media, Anthony found his way here at LabRoots, where he would be able to dabble in the two. Anthony is a technology junkie that has vast experience in computer systems and automobile mechanics, as opposite as those sound.
You May Also Like
JAN 17, 2020
Cardiology
JAN 17, 2020
Eating Walnuts Reduces Risk for Heart Disease
Walnuts may be more than just a tasty snack. Researchers from the University of Pennsylvania have found that they may also promote healthy gut bacteria, wh
JAN 29, 2020
Earth & The Environment
JAN 29, 2020
New Study Suggests Phytoplankton Will Thrive, not Decline
Based on current Earth models, which project warming seas and nutrient depletion, scientists widely believe that phytoplankton biomass will decline in
FEB 01, 2020
Earth & The Environment
FEB 01, 2020
Cut the ozone, help the plants
Researchers from the University of Exeter report in Nature Climate Change their findings of a new "natural climate solution”: reducing emissions
MAR 01, 2020
Plants & Animals
MAR 01, 2020
Are There Actually Two Distinct Red Panda Species?
Despite their rather conspicuous name, red pandas are nothing like the more widely recognized black and white giant panda. The former are members of the fa
MAR 19, 2020
Earth & The Environment
MAR 19, 2020
What's the Ocean's Oxygen Budget?
Have you heard the statement, “every other breath you take comes from the ocean?” Oxygen-producing phytoplankton are just one part of the oxyge
MAR 22, 2020
Plants & Animals
MAR 22, 2020
These Female Toads May Purposely Mate With Another Species
As a general rule of thumb, most of the world’s wild animals keep their instinctual mating practices within their own species bubble. But if you&rsqu
Loading Comments...