Short Wave - The Fish That Conceal Themselves To Hunt

Episode Date: August 11, 2023

All Things Considered host Juana Summers joins Regina G. Barber and Berly McCoy to nerd-out on some of the latest science news buzzing around in our brains. They talk NASA shouting across billions of miles of space to reconnect with Voyager 2, the sneaky tactics trumpetfish use to catch their prey and how climate change is fueling big waves along California's coast. What science story do you want to hear next on Short Wave? Email us at [e-mail] pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Hey, Shortwavers, Regina Barber here. With Burley McCoy. And Juana Summers. Now Wana, you're a host for All Things Considered. And Burley, you're a beloved producer here on Shortwave. And we've gathered you here today to talk through some of the latest science headlines that are giving us joy and tickling our brains. Thanks for coming to play with me.

No problem. I heard we are talking interstellar space shouts. And super sneaky fish. And then we'll learn why waves. are rising off the California coast on this episode of Shortwave from NPR. Okay, Regina, I can definitely identify with this idea of shouting into space a lot of the time, especially when I'm at home. Let's start there. Yeah, me too. So a couple weeks ago, NASA lost contact with Voyager 2.

This is the spacecraft that launched in 1977 and has traveled well beyond our solar system and is still sending back data. And they were worried they'd lost contact for good, but they reconnected to it last week by shouting at it across 12 billion miles or so. Okay. And what exactly do you mean by shouting? Yeah. So NASA periodically sends messages to make sure Voyager 2 is pointing its receiver towards Earth. And a few weeks ago, there was an error in a code that was sent out that resulted in the receiver pointing the wrong way, just two degrees. And that error was kind of like sending an email with the wrong attachment. And because of that slight shift, they lost contact.

The team was in emergency mode, but they were eventually able to send another message using the strongest signal they could, which was over twice as powerful as the original message. Linda Spilker, the Voyager mission scientist I talked to, called it shouting at Voyager 2. And it worked. We shouted Voyager, waded a day and a half, and Voyager came back and said, hi, I'm fine. Everything's great. Well, that sounds like a relief. But wait, there are two Voyager spacecrafts, right? Yeah, so there's Voyager 1 and Voyager 2, and they were both made to study the planet's inner solar system. And Voyager 2 is actually the only spacecraft to study Uranus and Neptune.

But since everything was still working after the initial four-year mission, scientists decided to give them a new mission to study interstellar space. Interstellar. Isn't that a Matthew McConae film? Yes, but in real life, we're talking about the space beyond our solar system, between star systems. a place we haven't really explored. And that's where the Voyager spacecrafts are now. And this makes them the farthest human-made objects from Earth. Also, just in case they encounter intelligent life, Voyager 1 and 2 are carrying golden records.

And these golden records have images, music, and greetings from all over the world. Okay. Now, for our second science story, we are leaving space and we're diving right into the ocean. Burley, tell us about these sneaky fish. Yeah, so this discovery is in trumpet fish, which are these long, stick-like fish, and they do this thing called shadowing when they're hunting other fish, which is basically when one fish follows another fish closely. And there was some mystery as to why they would do that. Maybe they do it because it helps them sneak up on their prey, but they could also do it because they encounter less drag when they swim in the shadow of another fish. Researchers didn't really know.

Okay, so how did the scientists get to the bottom of it all? So this is the really fun part. First, the researchers made these 3D printed models of trumpet fish and the fish they tend to hide behind called parrotfish. Then the lead researcher spent weeks painting them. He said he felt like Bob Ross and then took them out to a coral reef in the Caribbean where divers had seen this trumpet fish shadowing behavior before. And so two researchers would dive down, find a colony of trumpet fish prey,

and then set up two tripods with a nylon line between them. They attached 3D printed trumpet fish and parrot fish to that nylon line, kind of like an underwater clothesline, and then they'd put on this underwater puppet show with the fake fish swimming across the reef and watch how the trumpetfish's prey responded. Okay, so what did the prey do? How did they respond to these decoys when it looked like one fish was hiding behind the other fish? Yeah, so this illusion that the researchers set up with the fake trumpet fish hiding behind the parrotfish, it seemed to trick the prey. The prey didn't dart out of the way as urgently as they did when they encountered the trumpet fish on its own. So it seems these scientists got closer to answering the question of why these fish do this then, right? It seems to help them get closer to their prey while hunting.

Yeah, that's what the researchers concluded, which means this is the first time researchers showed that a predator outside of humans can conceal themselves from their prey by hiding behind another animal. And since coral reefs are disappearing, there's less coral to hide behind. So hiding behind other fish could end up being an even more important strategy for trumpet fish in the future. For our third and final story, we are staying in the ocean. The waves along the California coast are getting bigger over time. And that's due to global warming. Yeah. So our NPR colleague Nate Rot wrote about this recently for NPR.org.

Apparently California's winter waves have gotten about a foot taller on average since 1969. And the number of storms that produce waves greater than 13 feet tall have also become more common off California's coasts. So this is from a study published last week in the Journal of Geophysical Research Oceans. I mean, when you're talking about a foot taller waves, I'm not the best swimmer. That doesn't sound like good news for me. Maybe if you like to surf, it's a good thing. Yeah, I think for the surfers, it might be a better thing than for the rest of us. Surfers in California earlier this year said they saw the best swell in decades.

Yeah, but like Juana said, there are plenty of downsides that come with massive waves like damaged piers, crumbled sea cliffs, flooded coastlines. And when you combine that with rising sea levels, we're talking billions in damage to California's coast within the next few decades. Okay, that's no good. So how did they figure out that California's waves were getting bigger? Peter Bromierski, the study's author, used seismic records going back to 1931. I mean, I feel like when I hear the word seismic thrown around, I'm using. Usually thinking about earthquakes, not waves. Yep, yep, totally.

But it is connected, we swear. So basically when waves ricochet off the coast, they send energy back towards the sea. And when that energy hits incoming waves, it pushes energy downward. That creates a seismic signal that can be detected like earthquakes. So Bromerski was able to use that information to estimate the size of the waves. And this part is actually really cool. So we have data on wave height along the West Coast. from buoys, but they've only been measuring this since 1980. So by using this older seismic

data, Bromierski was able to go back further in time to activity patterns back to the 1930s. Okay, and we mentioned earlier that these higher waves off California are linked to global warming. What's the connection? Well, this new study adds to research suggesting storm activity in the northern Pacific Ocean has increased, as human activities have caused the world's temperatures to warm. That storm activity is the main source. of California's winter swells. Plus, we know that climate change makes storms more powerful and dangerous.

It makes storm surge and inland flooding more severe. So even though this study was focused on a specific region, the concern goes way beyond the California coast. Thank you again, Wana, for hanging out with us. Thank you for having me. Let's do it again and let's bring snacks next time. Definitely.

To see videos of the underwater fish puppet show, check out our episode page. This episode was produced by Gabriel Sanchez and Rachel Carlson. It was edited by our managing producer Rebecca Ramirez and by Viet Le and Christopher Antaliatta. Rachel Carlson checked the facts. Josh Newell and Stu Rushfield were the audio engineers. Beth Donovan is our senior director and Anya Grunman is our senior vice president of programming.

I'm Regina Barber. And I'm Berley McCoy. Thanks for listening to Shortwave from NPR. So, Wana, what is your favorite snack? I mean, there's so many, but I mean, seriously, who can beat a good chips and but the salsa's got to be hot. The salsa's got to be hot, like spicy hot, not to be hot, not warm left in my car hot.