MONTEREY BAY—For the first time, researchers have measured the heart rate of the world’s largest animal, the blue whale.
The details were published Nov. 25 in Proceedings of the National Academy of Sciences.
Researchers had previously trialed the sensor tag in small, captive whales, and it succeeded. Scientists from Stanford University and Scripps Institution of Oceanography, from a large inflatable boat in Monterey Bay, California, attached heart rate monitors to a single blue whale, held in place by suction cups.
“We had no idea that this would work and we were skeptical even when we saw the initial data. With a very keen eye, Paul Ponganis — our collaborator from the Scripps Institution of Oceanography — found the first heart beats in the data,” lead study author Jeremy Goldbogen, assistant professor of biology at Stanford University, said in a released statement. “There were a lot of high fives and victory laps around the lab.”
Analysis of the data suggests that a blue whale’s heart is already working at its limit, which may explain why blue whales have never evolved to be bigger. When diving, the whale’s heart slowed to 4–8 beats per minute and a minimum of two beats per minute. When the whale was at the bottom of the ocean feeding, that heartbeat raised 2.5 times more than the minimum, and then gradually slowed again.
Now, the researchers are hard at work adding more capabilities to the tag, including an accelerometer, which could help them better understand how different activities affect heart rate. They also want to try their tag on other members of the rorqual whale group, such as fin whales, humpbacks and minke whales.