Short Wave - Invasive Species: We Asked, You Answered

Episode Date: December 12, 2019

We couldn't stop at the spotted lanternfly! (We covered that invasive species in an earlier episode.) We wanted to hear about the invasives where you live. You wrote us about cane toads in Australia, zebra mussels in Nevada; borers, beetles, adelgids, stinkbugs, and so many more. From your emails, we picked three invaders to talk about with NPR science correspondent Dan Charles. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at [e-mail]. See 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

Hey-yo, Maddie here. You're about to hear a fun little episode that exists because of you. It was inspired by emails we got from Shortwave listeners from all over. In real talk, we feel extremely lucky to have listeners like you who listen to the show so much, write us with your own stories and episode ideas. So to keep episodes like this one coming your way, help us out. Support your local public radio station today. Go to donate.mpr.org slash short.

Not shortwave, just short. We can't even afford both words. Again, that's donate.npr.org slash short. And thanks. You're listening to Shortwave from NPR. Maddie Safaya here with NPR science correspondent, Dan Charles. Hey, Dan. Hi.

So, Dan, recently on the show, you brought to us a story of a bug called the spotted lanternfly. Spotted lanternfly. It's an insect, an invasive one that has been spreading across. eastern Pennsylvania and into surrounding states. They're pretty big, a little bit like cicadas. They jump more than they fly. Not dangerous to people, but definitely dangerous to some things like vineyards and trees. So at the end of that episode, we said,

if anybody listening has an interesting invasive species where they live, they should write us about it. And a lot of people did, Dan. Indeed. We heard about cane toads in Australia. Do not eat. Not good. zebra mussels in Nevada, Lake Mead, how in the world did they get there?

Stowaway bivalves, native to Russia. We heard about Asian carp, Brazilian pepper trees, hemlock woolly adelgids. So many plants and critters in so many places they should not be, Dan. That's right. So today, straight from our inbox, we're going to talk about three of them, three invasive species, all which reveal how delicate and complicated ecosystems can be. So, Dan, we've got a bunch of emails from people all over the country. about invasive species where they live.

We picked three to talk about in a little bit more detail, because it's a 10-minute podcast, people. We're just doing three. We are sorry if we did not get to your little invader in your hometown. So, Dan, let's get started. Okay. The first species on our list is the lionfish. We heard about it from a few of you, including Eric at the Florida Keys National Marine Sanctuary, who wrote, down here in the Florida Keys, we've got issues with invasive Indo-Pacific lionfish.

There's a lot of different efforts to eradicate or manage them, and they fortunately taste good, I will say they do, iPad phone, and can be fun to spearfish for. Now, different teams are looking at into automated drones with shock paddles, traps, and we, of course, have a lot of derbies for collecting them in mass. Dan, derbies and shock paddles. Here we go. The lionfish, first of all, it just looks wild. It looks like something out of a Dr. Seuss book. It's got spines coming out of its back. It's got fans for fins sort of spreading out. It's kind of sort of this reddish brown.

It's kind of pretty. It normally lives in coastal areas in the Indian Ocean or along sort of the Southeast Asian coast. Somehow it got to North Carolina and Florida. The speculation is people had it in an aquarium and like dumped it in the ocean. Yeah, sure. Sounds like stuff people would do. And it is now basically. scarfing up the ecosystem. It's eating

all kinds of native fish. It's got an incredible appetite. And there's a little bit of a mystery here because nobody knows exactly what keeps it under control in Asia in its native habitat. Apparently, you know, it's got predators there. The native fish, even like big fish, here off the eastern coast in the southeastern United States, don't seem to like to eat this creature. Yeah.

There is this one idea that basically humans, you know, we've got to step in. We've got to be the top predator here. So they've, you know, as you mentioned, they organized these hunting parties basically like spear the lionfish. Because the idea is, even if you can't eradicate the lionfish, if you can just like push their numbers down, it'll give more room for the native species to thrive. Okay. The second invasive species we want to talk about today is, I'm just going to read this email from Megan in South Florida. She wrote, although I studied entomology, amazing, in college, and found your episode on the lanternfly interesting, it doesn't hold a candle to the invasive species that has taken over the

Everglades. It's the python. Well, let's not compete out here, you know, but fine. I've seen pictures. I mean, so Burmese pythons are native to southern and southeast Asia. There's the suggestion that Hurricane Andrew had a breeding facility for Burmese pythons in 92, releasing a bunch of animals. But one of the experts, I talked to about this. His name is Matthew McCallister, says pythons were around way before that. He works for Big Cypress Natural Preserve in Florida right next to the Everglades National Park, and they've got pythons there too. He says the main source of the problem is that people are buying pet pythons and then realizing that they can't take care of them or don't want them and releasing them into the wild. So then a few pythons turn into many, many pythons. Yeah, exactly. And it's actually really hard to say how many are in the Everglades.

So Jill Gossimovich, who is with the U.S. Geological Survey, told me that if you're out there trying to find a python, Dan, like if you and I were walking around python hunting, we have about a 1% chance of finding them. So they're both simultaneously all over the place and also really well hidden. Yeah, really difficult to find. But the pythons that are out there are doing some serious damage. So there's this big 2012 study that showed that small mammals started disappearing in areas where the pythons kind of moved in. So we're talking like roughly 99% of raccoons and opossums disappear. And then there was this one other study from a group led by Bob McLeary that was kind of cool where they put radio transmitters in rabbits. So the researchers could track them.

And in 11 months, 77% of those rabbits were found in the stomachs of Burmese pythons. They actually tracked the rabbits into the python. Yes, yeah. So it's pretty sure, we're pretty clear that these pythons are making moves in this area and problems. And they're eating a lot of prey animals, but not a lot of things are eating them. Yeah. And it's really, you know, it's making a dent on that ecosystem. I have heard that there's some pretty extraordinary efforts going on to basically find them, track them down and kill them.

Yeah. I mean, it's a huge collaborative effort. We're talking like local, state, federal levels, community scientists, volunteers, academics. And some of those efforts include hiring contractors to go in and hunt them. At one point, using trained dogs to try to sniff out the snakes, even releasing radio-tagged male or female pythons to basically snitch on other snakes. So they would follow those snakes hoping that they would be looking to reproduce and then find a bunch of males around a female. Wow. Like take me to your leader. Yeah, they're snitches for sure, unwillingly.

And my favorite part of this is that they sometimes, because the areas are so large, they're looking at track those snakes using planes. What? Like flying over head and monitoring the pythons down below? Yes, and then sending people in by foot. So they are looking at snakes from a plane. It sounds like a military-style operation. Did you miss my snakes on a plane, Dan? Oh, no, I totally missed it. I mean, a snake's on a plane joke, Dan. Okay. Here we go. So the deal is, the sad truth is that they are not finding enough snakes. They're not taking enough snakes out of this area.

Matt McAllister, the big Cyprus guy I talked about earlier, told me that none of the tools we have right now are effective enough to curb the problem. And, you know, they're trying to keep the kind of the numbers down. Same with the lionfish, trying to keep the numbers down the best they can. And hopefully we'll learn enough about them that we can more effectively take them out of the ecosystem. Find some new balance. Yeah. All right. Final invasive species we are going to talk about today comes from another Dan in Colorado. Yes. Why don't you take it away, Dan? So this Dan wrote, I just listened to your episode on the lanternfly and it brought to mind a back. with the invasive tamarisk tree in the desert southwest.

One of the major impacts is their water consumption in the Colorado basin. The interesting piece is there's already been implementation of a biological warfare solution with the introduction of the tamarisk beetle. Jeez, okay, Dan in Colorado, one-two punch, tamarist tree, tamarisk beetle. Dan Charles Go. This is a super interesting story. Starts with the tree. It's more like a, it's a very small tree, like a shrub.

which was actually brought to this country more than a century ago from kind of the Asian, Central Asian region. Because this thing is very hardy, has deep roots. And the idea was it could help control soil erosion or be windbreak. But the thing has become kind of a monster in the west and the southwest. It's taken over riverbanks, replaced native willows and cottonwoods. There is that concern about it, you know, using up long. lots of water, although there's, I got to say, some controversy over exactly how much water it does use. There's no controversy over the fact. It burns like crazy.

Oh, no. Yeah, the leaves burn really hot and they just sort of catch fire and it's become, you know, instead of the native vegetation being kind of a fire break. Right. The tamarisk is like a fire spreader. Okay. So enter this beetle. Right. Which they brought in, again, from Asia.

The thing only eats tamarisks. It only eats the tamarisk leaves. And it has been in some ways amazingly successful. You know, they thought it would spread very slowly, like a couple of miles a year. Some cases it's spreading like 30 or 40 miles a year. But here's the twist. It's actually kind of been too successful. Because you have this situation where the tamarisks have filled an ecological niche that maybe needed to be filled.

Because some of these rivers, because we humans and agriculture and everything, have used so much water from these rivers, the water table has fallen so low that the native vegetation actually can't survive in some areas. So you get back to the original problem, which is the state of the rivers. Right, right, right. That's kind of the key to the whole thing, you know, in this sort of ecological situation that humans have actually originally disrupted in like one, two, three, many ways. Wow. So, Dan, just to wrap up here, we've been talking about invasive species that are kind of imported here to North America, where we are. But obviously, we also export them too. So what's a good example of that?

Well, right, because, you know, we always, everybody wants to be the victim, right? And so it's always the invaders coming this way. But, you know, the Americas have sent invaders other places, too. And like right now, there is an insect called the Fall Army Worm, which is a voracious pest. And it somehow got first to Africa and now to Asia, and it is like eating its way now into China, devouring important food crops, their own invasive species sent by us here. NPR science correspondent Dan Charles. And if you were one of the listeners who wrote us about invasive species, thank you for sharing your story. You can always write us with your thoughts or feelings about the show, ideas for what you'd like us to cover at shortwave at npr.org.

That's shortwave, one word, at npr.org. This episode was produced by Brent Bachman and edited by Viet Le. I'm Maddie Safaya, and we're back tomorrow with a look at a polar expedition to the top of the world. Until then, thanks for listening to Shortwave from NPR.