Whales and solar storms: a surprising link
Every year, hundreds of whales get stranded on beaches - many of them still alive, healthy, and with seemingly no reason to be there. But there’s a bizarre correlation between these strandings and the activity of the sun. And now, biologists from Duke University think they might have uncovered the specific connection, and it's to radio noise that comes from solar storms. They’re suggesting that whales might be using the Earth’s magnetic field to navigate, and their magnetic sense gets thrown off by this radio noise. Phil Sansom heard more from lead author Jesse Granger…
Jesse - We have discovered that there seems to be this really strange correlation, between grey whale strandings and things that are happening on the Sun. It seems as though there is a pattern between how active the Sun is, how much it's spewing out radiation, and how often these grey whales seem to be stranding.
Phil - I have to say, it sounds kind of like a 2012 style movie plot, that something going on with the Sun is making whales wash up on beaches. I mean what's the connection there?
Jesse - I know it's a bit crazy. I'm still a bit shook, and I'm still not sure I believe it, but what we really think is, so there are many animals on the planet that have the ability to sense the Earth's magnetic field, and they use that as essentially their own internal GPS system, while they're making these really long distance migrations. Perhaps these whales are magneto-receptive. They're also using the Earth's magnetic field when they're making this navigational trek. And the Sun might actually be disrupting the information that they're getting. And that's why we're seeing this pattern.
Phil - Is that something that's dangerous for whales?
Jesse - It is. It can potentially be deadly for many of them. A lot of whales that strand, actually strand dead, but we actually didn't look at any of those strandings. We only looked at these standings where the whales were alive, and there didn't seem to be a really obvious reason for them to be stranding. And we said, well, perhaps they're making a navigational mistake, and that's how they ended up washing onto the beach.
Phil - In that case, what's going on with the Sun that could disrupt the Earth's magnetic field?
Jesse - So we kind of came up with two hypotheses for what could be happening. Option one, the Sun could be pushing around the Earth's magnetic field. If you've ever had your GPS, like, jump over a couple of streets and it tells you you're not where you are, maybe that's what's happening.
Phil - It's like they're reading the magnetic field like a map, but all the contour lines have been pushed weirdly to the left or something.
Jesse - Yeah, exactly.
Phil - Okay. That's theory one. What's theory two?
Jesse - So theory two, the Sun does create a lot of radio frequency noise. Radio frequency noise can prevent an animal from sensing magnetic signals. There's radio frequency noise coming off the Sun during these solar storms, so perhaps it's actually turning off the whale's sensor altogether. So the whales using this GPS to navigate and all of a sudden it just turns off.
Phil - And what did you do to distinguish between whether it's solar storms disrupting the Earth's magnetic field, or it's the radio frequency noise that's messing with the whale's ability to read the magnetic field.
Jesse - So we can actually distinguish between those two things using some variables we measure here on the Earth. One of them is going to be looking at how much the Earth's field is wiggling around, and we measure that using a variable called the Ap-index.
Phil - What's Ap stand for?
Jesse - I don't know.
Phil - Okay, it's wiggling.
Jesse - It's wiggling. It's wiggling around, we look to see, do the whales seem to be stranding when the Ap-index is really high? So the Earth's field is wiggling around a whole lot, and the answer was no. I sat and got very frustrated and I was like, what the heck? What's going on? I'm so angry. Why didn't this work? I went back to the drawing board and we started to ask, okay, so what is the second option? That's where we came across this radio frequency noise, or RF noise for short. And our actual strandings were all happening so much more frequently when the RF noise was really, really high. However, you have to be really, really careful with stats like this. It's so easy to look at a correlation and try and say, well, obviously this must be affecting a magnetic sensor. But with correlation studies like this, all you can say is we see a pattern. Maybe this is an explanation.
Phil - If this is the case, what might this mean for whales?
Jesse - So one of the things about this study that I think has a lot of really great potential, is regardless of what the mechanism is behind this correlation, we see it. Whales strand alive more often when the Sun is really active, and whether or not this is actually an effect on a magnetic sense, we can predict when the Sun is going to be really active fairly well. Potentially, this could be used as another way of predicting when we need to be more active about looking for live strandings happening. So perhaps we can save one more live whale from dying on the beach.