Unexplainable - Why whales get beached

Episode Date: November 3, 2021

Every year, thousands of marine mammals end up trapped on beaches, but it’s often hard to figure out why. It’s even harder to figure out how much humans are to blame. For more, go to http://vox.co...m/unexplainable It’s a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

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Starting point is 00:00:22 For less, give AncestryDNA. Visit Ancestry.ca.C.T.A. today. Offer ends May 10th. Terms apply. It's unexplainable. I'm Noah's Hassanfeld. A few months ago, I called up one of our listeners. Hi there. Nice to meet you. Pao Guevara is a college student in Yucatan, Mexico, who wrote in with an idea for an episode. A while back, a single whale beach around here, and, you know, hearing that whole story made me really interested into why beachings happened in the first place. Every year, thousands of animals like whales and dolphins get stranded or beached. Sometimes it's
Starting point is 00:01:16 just the one. A dead whale has washed up on a local beach. Sometimes it's way more. This week, more than 650 pilot whales beats themselves in two separate mass strandings. According to some studies, strandings have been increasing, though it's not entirely clear why. Which brings us to POW's follow-up question. I was wondering to what extent humans are maybe involved in causing beeches.
Starting point is 00:01:41 You know, maybe human brought climate change or, I don't know, trade. So that's something that I'm very curious about. It turns out it's an incredibly difficult question to answer. Because while we know that humans are affecting the environment in tons of different ways, when it comes to individual species, our effects can be tougher to parse. The example of whale strandings gives us a really clear window
Starting point is 00:02:05 into why this can be so hard. And it also raises a trickier question. How do you protect animals when you're not sure exactly how you're harming them? This week on Unexplanable, three scientists on what makes whale strandings mysterious to begin with, why it's so hard to tease out the role humans play, and how we might be able to help.
Starting point is 00:02:26 Here's what we know for sure. Humans aren't the only cause of strandings. What happens in the modern world has been going on for millions of years. Nick Pionson is the curator of fossil marine mammals at the Smithsonian Museum of Natural History. And in 2011, he examined a group of fossils in Chile dating from well before the existence of humans. It was whale skeleton after whale skeleton after whale skeleton,
Starting point is 00:02:53 complete from nose to tail. Some of them stretched out almost like snow angels that kids make. I could see those stretch out for 40 feet wherever I looked. Nick wanted to figure out why these whales had stranded, and he spent years piecing together clues. You know, are these bailing whales, are they toothed whales? were they all adults? He analyzed how they were positioned,
Starting point is 00:03:18 what the geology of the region was like, and eventually he started closing in on a potential answer. I started moving towards this idea of harmful algal blooms being a cause. An algal bloom is basically what can happen when lots of minerals and nutrients run off from land into water. Algae populations explode, choking off everything around them. And we see this in the modern world. The neurotoxicity of harmful algal blooms,
Starting point is 00:03:44 can cause death almost instantaneously. So for millions of years, natural processes like algal blooms have caused whale strandings. But here's where things get muddy. Events like algal blooms aren't always natural. Today, they're often caused by runoff from human agriculture, which leads to a potentially frustrating conclusion. We can't really draw the line between where our effects dominate and where they don't. The biggest reason it's so hard to figure out what role human,
Starting point is 00:04:17 is because we don't fully understand strandings to begin with. Strandings are typically a mystery. Vanessa Parada is a wildlife scientist, and she says the big problem here is that every stranding involves different animals in different places under different conditions. If there was a silver bullet to go, okay, this is why a wild strand, that would have come out, but there are so many variables at play. Scientists have a great list of reasons that might cause a whale stranding, and sometimes it's pretty obvious what's responsible and how it connects to humans.
Starting point is 00:04:55 I don't know why people release balloons into the air. If your listeners are listening to this, please do not release your balloons into the air, because what goes up comes down. Basically, if you find a whale on a beach and it seems like it's just been hit by a ship or entangled in a net, it's not too hard to see the human effect. But without those obvious signs, it can be complicated to figure out what, killed a whale and what role humans played. Even if you know the actual cause of a stranding,
Starting point is 00:05:21 you still might not be able to figure out whether humans were involved. Take sound, for example. All whales rely on sound to get around the ocean, but different species of whales use sound in different ways. And that means human noises can impact them differently. So you have the toothed whales, which are the ones that use echolocation, and they're the ones that use the high-frequency sounds,
Starting point is 00:05:43 sort of like a... high-frequency pitches. And we also have the sperm whales. They use clicks. These toothed whales mainly use high-pitched sounds to navigate. So it's easy to imagine how sounds made by humans could mess up their whale GPS. They may be swimming along and there may be some misnavigation. They can't see the bottom of the water or they come into land and it gets a bit tricky for them to navigate.
Starting point is 00:06:13 or echolocate, and as a result, they may strand. But there are other types of whales that listen for entirely different types of sound. The Baleen whales, like the humpback whale and the world's biggest animal, the blue whale, and they will use these low-frequency sounds to communicate over long distances. And again, it's easy to imagine humans interfering here. So ships and underwater construction that might be interfering with whales being able to communicate. But the ocean can be a noisy place with or without humans. There also might be times where it's windy on the surface,
Starting point is 00:06:55 and that creates a lot of background noise that the animals find that it's quite tricky to have a conversation. It's like right now we're having a chat, and there's a big garbage or dump truck behind me in my backyard. And we can still have this conversation, but hold on a second. It's really loud. Just let me wait for this truck to pass. Okay, there it is. It's gone.
Starting point is 00:07:15 So given how loud nature can be on its own, when it comes to sound, it can be next to impossible to tease out just how much human noise specifically is interfering with whales. But even if researchers can pinpoint the exact role that human sound is playing, that's still only one possible cause of strandings. There's lots of other reasons whales can end up on the beach, even when they're communicating just fine. Like, they can actually get each other lost. So you might have an individual in the population, or the pod rather, who's not doing too well,
Starting point is 00:07:51 and it's leading the pod astray, and unfortunately it leads them to terrible waters, which is shallow and tricky to navigate. Sometimes the entire pod can be navigating perfectly, but they're actually being hunted. So there might be a killer owl that is trying to get a group of whales or dolphins into an area, and unfortunately the animals are so petrified that they will strand.
Starting point is 00:08:10 Other times, it might just come down to illness. A whale might be too weak to fight the current. These animals are susceptible to disease like we are as humans, they're mammals, they can pass on things to each other. But again, even if you do get proof that a whale died of an illness or got lost, you can't always rule out human involvement. Because as our listener, Pau mentioned at the top, humans are consistently and rapidly changing the environment through climate change.
Starting point is 00:08:35 And that is seeing a reduction in sea ice, which is bad news for animals that rely on food in the Arctic and Antarctic areas. You might see the reduction in homes for Antarctic krill, which is a main food source that the southern hemisphere humpback whales will feed on. Less food leads to hungrier, weaker whales, who might be more susceptible to disease and then get stranded. When a scientist tries to piece together the chain of events that led to a stranding, they need to consider all of these potential variables.
Starting point is 00:09:07 Plus, it can be even harder because whales travel huge distances and can be hard to study and track. And on top of that, strandings can just be hard to witness. It's not a time where you can sort of, oh, okay, we've got so much time to work out what's happening here. It's emotional. People are exhausted. They're working in cold environments, cold conditions. And to see animals die around you, it's awful. It's a really, it's a difficult thing. But there's at least one whale detective who remains unfazed, because she kind of has to. If I start thinking about the animal's suffering and the misery for it, then I lose my,
Starting point is 00:09:48 objectivity and my focus. Darlene Kettin is the person you call if you want to figure out what happened to your beached whale. I don't mean to sound like a cold fish, which a beeched whale would cheerfully eat. But that's how your brain works when you're trying to understand what happened to this animal.
Starting point is 00:10:07 Darlene's focus has led to a ton of whale adventures and some weird phone calls. I have found that if I'm out with friends or something, I shouldn't take a call and say, How long do you think it's been dead? It's actually given her a pretty great nickname. Some people have started referring to me as Dr. Doom because they only see me when something's dead.
Starting point is 00:10:35 After the break, Dr. Doom and a whale investigation. It's all about you. And when you fly with Virgin Atlantic in their upper class cabin, they take the VIP treatment to the next level. With a private wing to check in and your own security channel at London Heathrow, you can glide from your car to their car to their clubhouse, a destination in its own right in 10 minutes or less. On board, you can treat
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Starting point is 00:12:03 You actually sound sick. Unexplainable. We're back. Before the break, we talked about. all the different reasons whales can end up stranded, and why it's really hard to tease out the role that humans play. But to get a sense of why it's so hard to actually solve individual whale strandings, we called up a researcher at the Woods Hole Oceanographic Institution,
Starting point is 00:12:23 Darlene Kettin, aka Dr. Doom. Whenever there is a stranding, there is a team of scientists, and I'm one of them, that they contact, and we have to look at the dead bodies, So it really is a forensics problem. Basically, it's law and order, but for whales. In the aquatic justice system, the dedicated detectives who investigate strandings
Starting point is 00:12:48 are members of an elite squad known as marine biologists. These are their stories. When we look at the dead bodies, they tell us a great deal about the animal. All right, people, what if we learn? So it's really a way to unlock the lives of the animal.
Starting point is 00:13:13 She's definitely going to well on me when she finds out, I told you all this. So we can tell if a female has had calves. She was pregnant. Depending upon the species, we can maybe tell the age. 35 years old, she's a cupcake baker. It can be difficult because while we can indirectly understand from looking at the animal and from checking spinal signs and so on, we don't have a health record. No records, nothing on social.
Starting point is 00:13:43 media. They don't carry medical ID cards with them. No siblings, her father's deceased, her mom's in an assisted living in Boca. Their relatives won't talk to us. It's not on security cameras. And we do the best job we can, but sometimes it's an unsolved case.
Starting point is 00:14:00 And we can only about 50% of the time, if that much, give you a solid answer of why that animal died and why it's stranded. Darlene and other researchers, they'll look at stomach contents, they'll check eyes for cataracts, they'll probe wounds, and sometimes the answer becomes clear. But especially when it comes to trying to figure out the role humans play in strandings, things get really complicated really quickly.
Starting point is 00:14:34 Take one example from 2000. I got a phone call from some people in the Bahamas that had suddenly beak-twale strandings, about 12 animals. all over the beach. If you've never seen a beaked whale, they are wild. Beaked whales are really alien-looking. The males have huge tusks on either side of their jaws, and they have a very long frontal area, what's called a rostrum,
Starting point is 00:15:06 which is like your nose being pulled way out. So Darlene got this phone call, and she went to the Bahamas to check out the whales. Some of them were still on the beach, so she went to see them and smell them. The smell is called cadavering. It's gases that
Starting point is 00:15:22 dead bodies exude. Some of the whales hadn't been discovered right away, so they were pretty decayed. But some of them were ready to be examined. A few of the heads were collected and kept in freezers. So I went, as did some other people, and we dissected those.
Starting point is 00:15:42 Darlene shipped one of the heads back to her lab at Woods Hole in Massachusetts, so it could be put in a CT scanner. And when she dissected some of the heads, she found that the ears on these whales had blood in them. What we found out later was that there was a cooperative Navy exercise using sonars in the area where all these beaked whales stranded. And that blood in the inner ear led some people to say
Starting point is 00:16:11 it was the sound of the sonars. That must have destroyed their ears. But Darlene says that sonar may not have directly harmed the ears. Instead, because of other research she's seen, she thinks this pattern of earblood might have come from the whales experiencing a particular kind of stress. I can't really say panicking and freaking is not quite the right word, but becoming very disturbed by a novel sound.
Starting point is 00:16:42 So Darlene thinks that sonar may have caused, these whales to panic, which caused them to speed off blindly, and that's why they stranded. But she doesn't have definitive proof that's what happened. And even if she had that proof, she'd still only know that sonar caused these specific whales to strand, because other species of whales react completely differently to sonar. Pilot whales, when they hear a Navy sonar, they'll actually try to mimic it. So it's not like sonar always hurts whales. That being said, Darleney Darlene's research has had real effects.
Starting point is 00:17:17 Her work, as well as research from others, has been able to convince people that in certain specific areas, it's better to be safe than sorry, even if we don't have all the answers. And since then, many of the navies, not all, around the world, don't do sonar exercises where beaked whales are. So now, Darlene just needs to keep doing work like this for all the different types of whale strandings.
Starting point is 00:17:42 Painstakingly piecing together clues for who knows how many different mysteries. Every animal is a different story. Every beching might be a different reason. There's nothing more frustrating than a jigsaw puzzle with four pieces that are gone, and you'll never see the whole picture. But you can try digging deeper under the couch
Starting point is 00:18:08 between the cushions, looking for the pictures that are in cases of people like me. that's what keeps us in the lab and on the beach is looking for more and more information. And as many of the pieces of that jigsaw as you can get is the only way you're going to begin to understand what that larger picture could be. In the end, we might never have a complete answer
Starting point is 00:18:34 to our listener Pau's question of how much humans are responsible for whale strandings. And the same could be said for countless other ways that humans affect various species around the world. So scientists will keep digging behind couch cushions for more puzzle pieces. Each one gives us a slightly better sense of the harm that we're causing and how we might be able to respond. We really enjoyed not answering POW's question.
Starting point is 00:19:10 So if you have a question with an unexplainable answer that you think we'd like to dive into, there's a form on our website that we'd love for you to fill out. It's at vox.com slash unexplainable. This episode was produced and co-reported by me, Bird Pinkerton. Noam Hassanfeld wrote the music and edited the episode along with Brian Resnick and Meredith Hodnott. Manning Nguyen, check the facts. Thank you, Mandy.
Starting point is 00:19:37 Christian Ayala did our mixing and sound design, and we had extra help from Catherine Wells and Afim Shapiro. Lauren Ketz heads up our newsletter, and Liz Kelly Nelson is the VP of Vox Audio. If you want more whale content, Nick Pineson wrote one of my all-time favorite books about cetaceans. It's called Spying on Whales. So we'll link to that and to an article about Darlene Kettin's sonar detective work in our newsletter, which you can sign up for at box.com slash unexplainable. And then if you have thoughts, please email them to us. We're at unexplainable at box.com.
Starting point is 00:20:16 And if you feel like leaving, say, a nice review or a rating, I know that we would all really appreciate it. Unexplanable is part of the Vox Media Podcast Network, and we'll be back next week.

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