Seemingly healthy gray whales tend to strand themselves more often when the sun has blemishes known as sunspots or high solar radio frequency noise—two signs of a stormy atmosphere—according to a study published earlier this week (February 24) in Current Biology. The results hint at the possibility that whales have a magnetic sense and that solar weather is influencing magnetic field–based navigation.
“The study convinced me there is a relationship between solar activity and whale strandings,” Kenneth Lohmann, a biologist at the University of North Carolina, Chapel Hill, who did not participate in the research, tells The New York Times.
Duke University biologist Sönke Johnsen’s group teamed up with astronomer Lucianne Walkowicz of Chicago’s Adler Planetarium to gather the solar data. Johnsen’s graduate student Jesse Granger used a list of 31 years’ worth of gray whale strandings from the National Oceanic and Atmospheric Administration (NOAA) to identify 186 that likely represented strandings of healthy animals—they were alive and some even recovered and were released. Comparing the stranding data with the solar data revealed a tight overlap.
Sunspot activity, which waxed and waned over an 11-year period, “showed the exact same cycle” as the whale strandings, Granger tells the Times. When there were a lot of sunspots, whales were twice as likely to beach themselves. And solar radio frequency noise, which intensifies when the sun is storming, correlated with strandings even more strongly. When radio waves were especially intense, whales were four times more likely to end up on land.
Whether or not that solar noise is interfering with some sort of magnetoreception in the whales remains to be seen. Data on how distorted the Earth’s magnetic field was didn’t seem to coincide with gray whale strandings. Rather than affecting any sort of magneto-navigation, solar weather could influence whale physiology in some other way, perhaps by harming the animals’ health, Lohmann tells The Atlantic. “It is conceivable that the effect on the whales involves something that does not directly tie into navigation.”
John Calambokidis, a biologist at the nonprofit Cascadia Research who helped NOAA collect the data used in the study, says that the team’s approach to identifying live strandings was not foolproof and likely included some unhealthy animals. For example, a mass starving event in 1999 and 2000 occurred during a time of high solar activity and could be driving the correlations the researchers identified, Calambokidis tells the Times.
Jef Akst is managing editor of The Scientist. Email her at email@example.com.