Science Friday - Fishing For—And Saving—Sharks | Scientists Identify ‘ManhattAnt’ Spreading Across NYC

Episode Date: September 10, 2024

Shark fishing is alive and well, but the fishermen who do it are increasingly prioritizing conservation. And, an unknown ant was spotted in Manhattan in 2011, and it quickly spread through New York City. We now know what it is.Fishing For—And Saving—Sharks off the Jersey ShoreAt an undisclosed beach at 5:30 p.m. in New Jersey, shark fisherman AJ Rotondella and two clients wait for beachgoers to leave. Once the beach is empty, Rotondella cuts up some chunks of fish as bait, and casts lines into the water.“I shark fish, shark fish, shark fish, eat pizza, and shark fish … that’s pretty much it,” Rotondella said. “Waking up in the morning … wide open ocean, anything could be anywhere at any time. And I think that’s fascinating. No matter how long you’ve done this, you’ve never seen it all.”He has always loved fishing, and got into shark fishing 13 years ago, when his brother told him they could catch sharks from the beach. They caught two on their first day and could not catch another shark for the rest of the year.“That really got me interested because I knew it was possible, but I couldn’t do it again,” he said. “I … absolutely obsessed over this.”But Rotondella had a steep learning curve ahead of him. By trial and error, sometimes staying on a beach for multiple days, he learned how to read the tides, water temperatures, currents, and even phases of the moon to figure out how to track the sharks.Read the full story at sciencefriday.com.Scientists Identify The ‘ManhattAnt’ Spreading Across NYCNew York City is home to more than 8 million people. But there’s another massive population below their feet: ants.In 2011, when surveying ant populations on Broadway and Times Square, researchers got quite a surprise: an unidentified species of ant, which was soon dubbed the “ManhattAnt.” Since then, it has become the second-most populous ant species in New York City.Earlier this year, the first study on this unidentified species was released. It concluded that this species, Lasius emarginatus, likely hitchhiked from Europe to the US. Though their populations have grown tremendously, it’s unclear how the ants are interacting with New York’s native ants.Joining guest host Sophie Bushwick to discuss this ant species is Dr. Clint Penick, assistant professor of insect ecology at Auburn University in Auburn, Alabama.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Invasive species are thriving in the heart of Manhattan. So now we have this sort of mix of species that, you know, from all over the world that are coming together. And I guess, you know, much like humans are sharing their culinary culture and exchanging foods. It's Tuesday, September 10th. And of course, it's also Science Friday. I'm SciFri producer Kathleen Davis. In 2011, researchers doing an Ant Census in New York City found something interesting, a species that was a species that was. was new to the country. And they found it in an unexpected place, in flower beds, and in sidewalk

cracks, in Times Square, and on Broadway. We're now learning more about what this species is and how it interacts with other urban insects. But first, we're bringing you a story about conservation-oriented shark fishing. Here's guest host Sophie Bushwick. Sharks face a lot of challenges in our modern world. There's climate change, of course, and then there's overfishing. Unless you live on a coast, it might surprise you to learn that shark fishing is alive and well. But it's not always a bad thing. An increasing number of shark fishermen are chasing sharks with the goal of conservation. My next guest tagged along with a conservation-oriented shark fisherman in New Jersey.

He joins me now to talk about it. Alan Yu, reporter for W. H.Y. and the Pulse, based in Philadelphia, Pennsylvania. Welcome back to Science Friday. Thank you very much having me on. Alan, you got to go on a trip chasing sharks at the Jersey shore. Tell me about that experience. What was it like? So one shark fisherman told me beforehand, and I think it captures it perfectly,

is that for a long time, nothing happens. And then everything happens at once in the space of a few minutes. So we waited for everyone to clear the beach first, so there was no one in the water, no one on the boat, so no humans in the water. And then there was a lot of setup because they need to have a really sturdy fishing rods that can handle a shark because sharks can weigh hundreds of pounds. And then there are some lines that the shark fisherman AJ manually cast. And then there are some lines that he actually uses a drone to fly offshore so you can cast them further out.

And then once those are set up, you basically just wait. Every time you see a line shaking, AJ will sprint across the sand to see if there's something at the other end. And we got a few bites every now and then. Sometimes a shark would bite half of fish and then leave the other half. But it took more than three hours before we caused a shark. But once we had a bite, then it made for like an action-packed one minute. And to me, it just seems a little counterintuitive that fishermen are catching sharks with the intent to save them. So can you explain that to me?

Yeah. So the fisherman I went out with, AJ, says that he likes to catch sharks because of the challenge. and he likes to do it from a beach because he can get right up next to a shark, whereas if he did it from a boat, he will be looking down on them. And he says that that contact makes him appreciate and respect sharks more because it's so hard to catch one. When he was starting out more than 10 years ago, he said that he would spend multiple days on a beach before he could catch a shark. And so he really respects these as apex predators that are not easy to catch.

he's very committed to doing catch and release fishing. So he says that he does everything he can to make sure that the sharks are not harmed and that they experience the least stress possible. And we have a clip of him saying that. You just want the fish to survive. The end of the story. The point is for this to be a sustainable fishery,

you need to have fish swimming off and living a happy life after the encounter. And the other thing is that shark Anglers like AJ, they also work with shark researchers because the people who are fishing for sharks are often out there far more often than the researchers are. And so it's a convenient way to get sharks and then the researchers can tag them, sample them, and then release the sharks back out again. And AJ does work regularly with a shark researcher at Monmouth University in New Jersey. A.J. said that it's good to have the sharks living a happy life after the encounter.

So how are our shark populations doing in that region? The research shows that shark populations are rebounding in the northeastern U.S. and in the Atlantic Ocean, but quite a few species are still endangered. So they're not quite as endangered, but that they are making a bit of a comeback, at least in the Atlantic. And what about conservation biologists? Do they have any thoughts about this new twist on shark fishing? Yes, they do. So first of all, it's certainly an improvement over the past when people would fish for sharks like it was a trophy hunt. I talked to a professor of fish conservation, Andy Danochuk, who remembers going out to peers in the 1970s and seeing dead bodies of sharks being hung up as actual trophies. That has long past now, and most people who fish for sharks do catch and release like AJ does.

So Andy Dano Chuck, he likes shark fishing himself, and he became interested in conservation, partly because he liked shark fishing. Here's some tape of him. But then the more that I fished and then the more that I was observant of what was going on in the environment, I started to realize that in order for us to have a future for being able to fish for these, animals, we need to think about how we can use science to better inform their conservation and management. So the research focus now is actually working with the shark anglers to make sure that they

do what they can to make sure that sharks can survive being caught and that they're not harmed by it because even though people like AJ will do whatever they can to minimize the stress, it is still stressful for a shark to be yanked out of the water for a minute before they get put back in. I know a lot of people who like to fish, but not everyone is fishing for sharks. And then you have recreational activities like diving where people do want to see sharks and then surfing where they don't, which is to say that there's a lot of interaction between people and sharks, whether it's wanted or not or intentional or not. Do scientists think we could all live in harmony? I think yes, but it's a complicated way to reach that. Andy Nanocuk talked about this.

speak. He said that because you have people with these competing and overlapping interests, and you can't control the sharks, right? All you can do is control the people. And so that's why he says that he sees his work in fish conservation as much as a social science as it is a science, because he can study the sharks, he can see where they are. But then at the end of the day, it's about figuring out how do you work with the people who are interacting with the sharks in one way or the other so that you can protect the shark populations, but then people can also still get to do the fishing that they like to do. Alan Yu, reporter for W.H.Y.Y. and the Pulse, based in Philadelphia, Pennsylvania. Thanks for

joining us. Thank you. It's a pleasure to be on, as always. New York City is home to more than 8 million people, but below our feet, there's another massive population. Ants. They're in our sidewalk cracks, our flower beds, even our apartment. Despite the many ants going about their business in urban areas, they've remained pretty understudied. So scientists got a big surprise in 2011 when they discovered a new ant in town, and on Broadway, no less, lovingly dubbed the Manhattan. Insect ecologists finally know more about this little ant in the big city, thanks to my next guest, Dr. Clint Pennick, assistant professor of insect ecology at Auburn University in Alabama.

Welcome to Science Friday. Hi, Sophie. Happy to be here. You've recently identified this ant, and it's not a brand new species. So what do we know about it? Well, we found out that the Manhattan ant traveled to New York City via Europe. Like several of the other ant species that we have in Manhattan, there are immigrants just like many of the immigrants that came to the city through multiple waves.

And how unusual is it to discover a new type of insect in an urban area like this? It might not be as unexpected as you would think. we actually have a better handle in a lot of natural spaces that scientists have been working in for many years than we do with our own cities. Our group was actually the first around, you know, over a decade ago to study the biodiversity of ants in New York City. No one in the history of the city had ever thought to do that before. But people have actually, you know, looked at natural places and stuff outside the city. And I've seen pictures of you collecting data in the city. and I have to ask about your method.

It kind of looks like you're sucking up ants with a straw. So tell me more about that. Yeah, so, yeah, we have this special device that we call it an aspirator, which is basically a mouth vacuum. So it has a tube that you put in your mouth, and then it's attached to a vial with a little filter in it, so the ants don't go in your mouth. And then we point it like a little gun at ants on the sidewalk and then inhale,

and that's how it works. And what have we learned about New York's ants from this? So I originally began working in New York City to understand what ants are eating. How do they survive and thrive in a habitat that basically looks like a concrete jungle? And what I found is that the main ants that we see in the sidewalk, the most common ones, survive because we're sloppy, basically. So we drop food, we spill things, and the ants clean it up. They're basically the unpaid garbage workers of New York City.

But the new ant that showed up, the Manhattan ant, is different. And so that's one of the questions that my lab is trying to figure out now is how they are able to survive on these sidewalks because what we do know is that they don't seem to be eating human foods. Give me an example of some of the human foods they're eating. Oh, well, I mean, the classic one we always go to is hot dogs because it's New York City, there's hot dog stands. And we've actually done some sort of back-of-the-envelope calculations to figure out how many hot dogs the ants just living on Broadway in New York City eat every year. and it's 60,000. The ants eats the equivalent of 60,000 hot dogs a year. That's wild. But the Manhattan's aren't doing this. So how are they establishing themselves? Yeah, we don't exactly know yet what the Manhattan ants are doing to survive. But what we seem to think

that they're doing is that when we see them foraging, they're climbing up trees that are planted along the sidewalk. And so whatever they're eating is in the canopy of these trees. And so there's bugs and other insects that are up there. And some of them produce this substance, the sugary substance that's called honeydew. And so these are insects that feed on plant fluids. And then basically their poop is sugar. And that's what the ants we think are eating. So the insects that do that, this is reminding me of another invasive species, the spotted lanternfly. Is that something that produces honeydew? Yes, exactly. So New Yorkers now are pretty familiar with the sight of these pink and purple lantern flies, which are really beautiful,

but are really troubling invasive. And so lanternflies, yeah, they do. They feed on plant tissues and they produce honeydew. And we've actually seen Manhattan ants interacting with them. So now we have this sort of mix of species that, you know, from all over the world that are coming together. And I guess, you know, much like humans are sharing their culinary culture and exchanging foods. Hopefully it turns out good for the human residents in New York. But yeah, they definitely interact with lanternflies. Yeah, I'm kind of curious about what you think the result would be of this kind of interaction. This is something that ants have evolved to do in a number of different contexts. But when they feed on honeydew produced by something like lanternflies, the ants obviously

are getting food from this mutualism. What they give back to the insects is protection. So ants can basically serve as the bouncers and bodyguards for honeydew producing insects like lanternflies. So if this continues, and especially if the Manhattan ants spreads out of New York City as it's already starting to do and makes it into agricultural areas where lanternflies are more of a pest, it's possible that these ants could be protecting lanternflies and helping them develop larger populations. So that's not good. We're supposed to be stomping on lanternflies, not helping them. So, I mean, is there anything we can do to prevent Manhattan's from doing that? Well, right now, we're just trying to keep an eye on them. When we discovered them, they were pretty rare.

We found them in a couple kind of deep forested areas of parks in New York City, kind of tucked in dark parts of Central Park. But what we found is that they're actually thriving. They're able to move into the most urban areas of the city. And so we really don't know how their populations are going to impact native species or other invasive species like lanternflies. So over time, we've realized that they've become more prominent than we would have guessed at the beginning. And my lab is focused on tracking their populations and trying to tease apart what their effects could be.

And one way people could help is that we actually created a project through eye naturalist called Project Manhattan. And on that site, you can take pictures of ants that you think are Manhattan ants and upload them. And then that helps us track their populations and see where they are. What do they look like for people who are going on a hunt for this kind of ant? Yeah, to me, I always tell people that they're kind of big, but they're not really that big. To an ant person, they're bigger than a lot of ants, but they're kind of a medium-sized ant, but the characteristic that can help someone ID them is that they're red and black. And they're the only ant of that size in New York City, and really through much of the northeast,

that you'll commonly see that's red and black. They have a black head and a black abdomen, and then their thorax is red. And you've also mentioned the native species of ant that was found in Manhattan before these ants moved in. So what is the most common ant in the city? Yeah, so Manhattan is quite diverse. There's a lot of ant species there. We've actually documented over 40 different species of ants just in Manhattan alone, which is more than has been found in the nearest protected area outside the city. So by all measures, New York City is quite diverse when it comes to ants. The most common ant in New York is like the Manhattan is not native. It's called the pavement ant. They're also from Europe, but they've been there much, much longer. So the pavement ants probably came to New York City. in some of the early waves of immigrants. They've at least been there 100 years, potentially longer.

But they've kind of been adopted as naturalized residents, like many New Yorkers, like many different people who come to New York. They live mostly on the sidewalks. They're not a huge pest. They don't get in people's homes. But they're the ones up until the last 10 years or so that have dominated the sidewalks of New York City. And how are these species interacting?

Do they seem to get along okay? We don't know that yet, but we do know is that when they do meet each other, they sometimes fight. So we've seen the Manhattan ant tearing apart some pavement ants and probably the opposite happens as well. So right now it could just be, you know, a battle for the for the streets to see which ant comes on top. And learning about this overlooked activity is making me think of a great line from your paper about these ants. You wrote, often the only visual non-humans in Times Square are humans dressed as Disney animals. And yet hidden in this flower pot, was a whole society of animal beings.

Yeah. So this is something that really surprised me. I mean, I've been working in New York City on ants for the better part of a decade. And where we work tends to be in the Upper West Side or in some of the park habitats. But I went with my students, Samantha Kennett, and we decided to look in the most dense, the most urban part of the city, which is Times Square. And sure enough, all we had to do was peek inside a flower pot and we found a full colony of the Manhattan thriving.

you know, in the midst of, you know, thousands of people who were probably there already. And, yeah, and like what we wrote in the paper as sort of, you know, a tongue-in-cheek joke, but, you know, there's all these characters dressed up as animals in Times Square. But the only animal besides us, humans, were the Manhattan's, and they seemed to be doing quite well. And I wanted to get back to the citizen science aspect of this. We know that we want to stop invasive species, so that involves stomping on lanternflies. We know that we want to learn more about the Manhattan. and you've got that project on i naturalist. Do you have any other advice for folks who might want to

get involved in ant hunting? Yeah, I mean, ants are one of the easiest things to find. I mean, whether you want to find them or not, they end up in your kitchen. They end up, you know, on our sidewalks. And so, yeah, I do ask people, just pay attention. There's a lot of species. We have, you know, something like 800 species of ants that are native to the United States. And like I said, 40 of them are in our biggest and densest city. So if you can get out there and take some photos of them and upload them to eye naturalists, we would certainly appreciate it. That's all the time we have for now.

I'd like to thank my guest, Dr. Clint Pennock, Assistant Professor of Insect Ecology at Auburn University in Alabama. Thank you for joining us. Yeah, thank you. And that's all the time that we have for today. A lot of folks don't make the show happen, including John Denkosky. Annie Niro. Jason Rosenberg

Rasha Aireti Shoshana Bugsdown And many more Tomorrow a look into the unexpected neuroscience of cows But for now I'm SciFry producer Kathleen Davis

We'll catch you then