PCB Contamination, Space Flowers, and Python Removal

12:07 minutes

Polychlorinated biphenyls, or PCBs, have been banned worldwide for the past 30 years due to environmental concerns. According to a study in the journal Scientific Reports, high levels of the toxic chemical have been detected in the blubber of whales and dolphins off the coast of Europe. Rachel Feltman from The Washington Post discusses this story and other selected short subjects in science. Then, Craig Pittman of the Tampa Bay Times describes an unusual Floridian contest—the 2016 Python Challenge Burmese Python Removal Competition.

Segment Guests

Rachel Feltman

Rachel Feltman is author of Been There, Done That: A Rousing History of Sex, and is the host of “The Weirdest Thing I Learned This Week.”

Craig Pittman

Craig Pittman is a Staff Writer for the Tampa Bay Times in St. Petersburg, Florida.

Segment Transcript

IRA FLATOW: This is Science Friday. I’m Ira Flatow. Later in the hour we’ll be talking about a new planet, a mysterious planet far out in our solar system. But first the crew of the International Space Station, a little closer to home, woke up to a pleasant surprise last weekend, a bouquet of fresh flowers grown right there in their space garden. Astronaut and gardener Scott Kelly proudly shared a photo of the bright orange zinnia bloom.

But these were not the first flowers to bloom in space. Here with more about what it takes to grow flowers in zero g, as well as other selected short subjects in science, is Rachel Feltman. She writes for the Speaking of Science blog at the Washington Post. Good to see again Rachel.

RACHEL FELTMAN: Good to see you too, Ira.

IRA FLATOW: Tell us about these flowers.

RACHEL FELTMAN: Right. So Scott Kelly was able to bloom some zinnias in the same apparatus that the astronauts have used to grow lettuce now a couple of times, which they’ve actually eaten. And it’s all part of NASA’s initiative to learn how to grow vegetables in space, ideally so that astronauts have a source of fresh food in the long term spaceflight, like with missions to Mars.

It’s not the first flowered bloom in space. It’s not even the first flower grown entirely in space. That was probably at done on the pre-ISS Russian spacecraft.

IRA FLATOW: And we also had Don Pettit, who was on and talked about broccoli he grew in space.

RACHEL FELTMAN: He brought up seeds he had germinated in little plastic baggies, and actually grew a sunflower, though it didn’t do very well. So Kelly was working with this apparatus that’s designed to keep plants properly moistened and anchored in the soil, even in low gravity. And it’s very complicated. It’s easy for them to get over-watered. And there was a lot of rot happening.

And he actually asked the mission team if he could just decide when to water the plants. He said you know, if I was working on a garden at home I would look at it every day and decide what it needed. So they gave him more free reign. And sure enough he was able to nurse the flowers back to health. And we have a bloom.

IRA FLATOW: He had a greener thumb than NASA did.


RACHEL FELTMAN: Yes. And it’s actually great, because it shows that an astronaut working with the plants is probably going to do a pretty decent job of taking care of them. And I think the hope is that they’ll move on to more traditionally edible flowering plants like tomatoes, and just keep working on increasingly complicated stuff.

IRA FLATOW: Next up a really– a troubling story about PCBs. They were banned worldwide in 1986, but they’re showing up again.

RACHEL FELTMAN: Yeah so polychlorinated biphenyls were invented in the ’20s, and were this great technological marvel. They have a lot of applications in plastics, and as cooling liquids for transformers and electronics. And the thing is that they really don’t break down. And they’ve been shown to have a lot of toxic effects across the board for all kinds of animals, including humans.

So they’ve been banned for a long time now, and a lot of clean up after efforts have been made. But they are not water soluble. So they tend to get stuck to sediment, and get kicked back up in the water.

So these researchers examined whales in Europe, and found that killer whales, bottle nosed dolphins, and striped dolphins had some of the highest ever concentrations of PCBs recorded. The reason it’s so dangerous for marine mammals like whales is that because the PCBs are fat soluble they build up in fatty tissues, like blubber, over time. Because whales live so long they have lots of time to accumulate them. And because they’re so high on the food chain they eat lots of other organisms that have PCBs in them.

So basically the whales have it particularly bad. And the concern is that if whale populations are suffering for other reasons, having high levels of PCBs in their system is not going to help them recover. So the concern is that there are certain groups that might even go extinct.

IRA FLATOW: There’s no danger that it’s in the fish that we eat, the kinds of fish?

RACHEL FELTMAN: Well you know it that would be something they would have to look at specifically. Any animal that has a lot of fatty tissue and is in an area that’s contaminated with PCBs is probably not something you want to eat.

IRA FLATOW: Now let’s talk about the world’s longest prime number. How many times are we going to hear another story about a longer prime number?

RACHEL FELTMAN: An infinite number of times.


IRA FLATOW: Good one.

RACHEL FELTMAN: So the University of Central Missouri is now responsible for its fourth record-breaking prime number. It’s 22 million digits long, which is five million digits longer than the last record breaker. And it came from this computer software from the Great Internet Mersenne Prime Project.

Basically any computer can run it in the background. And the only way to find prime numbers at this magnitude is you just go through every number and check if it’s prime. So the University of Central Missouri contributes the most computing time of anyone to this project. So sure enough they keep finding winners.

IRA FLATOW: And they’ll keep repeating this, unlike a prime number.


IRA FLATOW: I had to get that one in there. I was thinking about this, does a prime– does a number exist if it’s not written down? I mean it’s a number.

RACHEL FELTMAN: Right. An interesting– that’s an interesting point because the computer found this number in September, but there was a malfunction and it didn’t alert anyone. So people only saw it in January. So the question is, when was the number discovered? Because obviously numbers always exist, but does that count if a human didn’t observe it? You know, if a tree falls in the woods– if a prime number–

IRA FLATOW: My thought exactly. You know are we just talking about concepts with numbers? They don’t exist until we write them or think them.

RACHEL FELTMAN: It’s pretty mind boggling stuff.

IRA FLATOW: Well my brain is hurting. Let’s move on to something my brain can get around, and that’s the Venus flytrap. I had one as a kid. Doesn’t everybody have one as a kid?

RACHEL FELTMAN: Yeah. They’re really cool and really weird. And they just got weirder. Researchers found that flytraps can kind of count in a weird way. They’re not really sure how this happens. Obviously Venus flytraps don’t have brains.

But they found that the plant can basically keep track of how many times it’s touched. When they touch the Venus flytrap once nothing happens. But it’s like a clock starts.

And if it’s touched again within a certain number of seconds then it traps the thing that’s touching it, but that only partially. It waits for a third touch before closes all the way. And then it’s not until the fifth touch that it starts releasing digestive enzymes, and releases more and more based on how many more times it’s touched.

And it’s really ingenious because that’s allowing it to not waste its time on things that are dead that fall into it, on things that brush past it that it’s not going to be able to capture. And it also allows the plant to really be in charge of how much energy it’s expending. So a really lively big bug is going to touch it more, and is going to get more digestive enzyme. So they really have no idea how it manages this, and it’s pretty cool.

IRA FLATOW: How does it count, basically.

RACHEL FELTMAN: Right. So you know they’re going to sequence its genome and try to figure out what electrical impulses are making this happen.

IRA FLATOW: Wow, that’s– you know the more we learn about plants the more fascinating it is. Thank you, Rachel.


IRA FLATOW: Rachel Feltman writes for the Speaking of Science blog at the Washington Post. Now it’s time to play good thing, bad thing.


Because every story has a flip side. And while many eyes are focused on politics, the real action is occurring in Florida. Last week marked the start of an unusual contest in the Sunshine State, the 2016 Python Challenge Burmese Python Removal Competition. That’s right, for an entry fee of $25, you too can sign up to help rid the Everglades of pythons.

Joining me with the good and the bad and the huh? of this hunt is Craig Pittman. He’s a reporter covering environmental issues for the Tampa Bay Times. Welcome to Science Friday.


IRA FLATOW: Tell us about this. What’s good about this? Why have a python round up? I mean we’re going after wild creatures.

CRAIG PITTMAN: Well you mean besides that it’s more interesting than the presidential race? I guess that the big thing is that pythons are sort of the ultimate example of an invasive species. Florida has more invasive species than any other state, and this is the poster child for it. And so the state Fish and Wildlife Conservation Commission is holding this python challenge to raise awareness of the invasive species problem, and also get rid of a few of the thousands and thousands of pythons that are infesting the Everglades.

IRA FLATOW: Well tell us about– what danger do they pose?

CRAIG PITTMAN: They are voracious eating machines. Scientists have found that everywhere there are pythons, they pretty much wipe out everything else. They found that between 2003 and 2011, the areas where the pythons had proliferated saw a 99% decrease in raccoons, a 98% drop in possums, a 94% drop in white tail deer, 87% drop in bobcats, and no rabbits or foxes period.

IRA FLATOW: Wow. And so– and they’re spreading?

CRAIG PITTMAN: Yes, yes they are. There was a captive breeding experiment involving endangered rats, believe it or not, down in the Florida Keys, where they released some of the captive bred rats with radio monitors. And one researcher tracking one of the rats discovered radio monitor was broadcasting from inside a python, which was their first clue that pythons can swim.

IRA FLATOW: So how many pythons can they hope to eliminate? I mean there have got to be thousands of them. How many– what percentage can they get?

CRAIG PITTMAN: Well let’s put it this way, they had one of these in 2013 and captured all of 68. As of today they have caught 39. So that’s an amount that one female python could pretty much replicate with one clutch of eggs.

IRA FLATOW: So this is really sort of futile, what we’re talking about.

CRAIG PITTMAN: Well the scientists like it though, because it gets them a lot of new information. For instance they said that the pythons captured in the 2013 hunt showed them some different information as far as the diet they’re eating, so that’s been helpful.

IRA FLATOW: So what could be the bad thing about this?

CRAIG PITTMAN: That some people might think this is the be all, end all answer to getting rid of the pythons, when in fact it’s just a drop in the bucket, really. And the thing is they– the people in charge acknowledge that. They say look, we know this isn’t going to eliminate the problem. We’re just– we’re trying to do this as one way to get some of the pythons out of the Everglades.

IRA FLATOW: I understand there are animal rights concerns here.

CRAIG PITTMAN: Well it’s interesting. Yes, so the People for the Ethical Treatment of Animals sent a very sternly worded letter to the Wildlife Commission and said please don’t let the hunters decapitate the pythons with machetes, because then they writhe around in agony for a while. Now you might think PETA would then say please save the pythons. But no, not even PETA likes the pythons. They said instead have them blow their heads off with guns. That’s a better way to kill them.

IRA FLATOW: How many shots– you know, with a wriggling python, how many shots is it going to take? And how much ricocheting is it going to be? How many people are going to get hurt from the buckshot?

CRAIG PITTMAN: Well that’s a good question. You know in Florida we are the Gunshine State. But the guy who is the most successful python hunter in Florida history is a great grandfather with a shotgun, who is employed by one of our state agencies to go around. He says he can actually smell the pythons, their sort of musky odor. And he’s killed more than 300 of them personally.

IRA FLATOW: Wow. He’s a one man python army.

CRAIG PITTMAN: He is, he is.

IRA FLATOW: You need a few more of him and you won’t get more than three dozen pythons.

CRAIG PITTMAN: Well I suggested cloning the guy. I mean that would make sense.

IRA FLATOW: There you go, there you go. Thank you Craig. Well we’ll keep– we’ll stay on this story, OK?

CRAIG PITTMAN: OK, sounds good.

IRA FLATOW: Craig Pickman– Pittman, a reporter covering environmental issues for the Tampa Bay Times. And he has a forthcoming book, Oh, Florida, coming out in July.

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