Freshwater Quality, Fungus-Farming Ants, And A Shrimp That Kills With Sound
A recent study indicates that the nation’s waterways are contaminated with human-made chemicals that water treatment facilities often don’t remove. Researchers took water samples from 35 different rivers and streams and tested for the presence of 719 different chemical compounds—and found over 400 of the materials they tested for, including pesticides and pharmaceuticals. Another study found that runoff from roadway ice treatment is increasing the salt level in lakes. Sophie Bushwick, senior editor at Popular Science, joins Ira to talk about freshwater quality and other stories from the week in science, including a look at how much sleep you really need, the history of ants farming fungus, and a shrimp named for Pink Floyd that uses sound as a weapon.
Sophie Bushwick is technology editor at Scientific American in New York, New York. Previously, she was a senior editor at Popular Science.
IRA FLATOW: This is Science Friday. I’m Ira Flatow. You know you should try to get more sleep. You know that. Right? But it’s hard. There’s so much to do, so many things to binge on TV. So maybe it wouldn’t hurt to stay up just a little bit while longer. Huh? Joining me now to talk about just how much sleep you need to stay sharp, and other selected short subjects in science is Sophie Bushwick, senior editor at Popular Science. Welcome back, Sophie.
SOPHIE BUSHWICK: Thanks for having me.
IRA FLATOW: Do you know anybody who gets eight hours of sleep?
SOPHIE BUSHWICK: I don’t. But it turns out, we all should be aiming for that. In the study you mentioned– so the researchers had a group of people. They all got eight hours of sleep, and then went and did a bunch of cognitive tests. And then for two weeks after that, they restricted their sleep schedules. So one group for a few days got zero hours of sleep at night. And the following day after that sleepless night, they took the same cognitive tests again, and they did much, much worse on them. It was almost as if they were taking the tests while drunk.
IRA FLATOW: Wow.
SOPHIE BUSHWICK: And even the groups that got a little more sleep also had cumulative problems. So after three days where they only got four hours of sleep a night, a different group of test subjects also reached the same level as the group that wasn’t sleeping at all. And for the people who were getting six hours a night, it took them 10 nights to reach the same stage. But the thing is that while they were all performing poorly on these tests, they thought they were doing fine.
IRA FLATOW: So that one hour or two hours really makes the difference, between six and eight.
SOPHIE BUSHWICK: It’s definitely does, especially over time. So if you’re getting six hours a night for night after night after night, that’s going to have a cumulative effect for you.
IRA FLATOW: Explains a lot of things in my life.
IRA FLATOW: You have two stories about freshwater in the US lakes and rivers and such, and one looked at human-made chemicals in water. It was astounding.
SOPHIE BUSHWICK: Yeah, it was really upsetting. They tested for over 700 different human-made chemicals. And they found more than half of the chemicals they tested for were present in the water, and we’re able to have an effect on cells, which is really disturbing news. When you consider that 85,000 different chemical compounds are actually manufactured in the US, and so the number that they tested for was a fraction of what could be out there.
IRA FLATOW: What kinds of things did they test for– are we talking about here?
SOPHIE BUSHWICK: Well, the top 10 items that they would find were– eight of them were pesticides, and then two of them were pharmaceutical compounds, one of them was everybody’s favorite, caffeine, and the other was a compound that’s used to treat Type 2 Diabetes.
IRA FLATOW: So if, you know, I’m just thinking out loud now, so if you think you’re getting organic food and it has no pesticides or whatever, if it’s in the water that they’re using to process the food, then maybe you’re getting the stuff in there anyhow.
SOPHIE BUSHWICK: That’s a really interesting point. And then another thing is that water treatment plants don’t filter out every single one of those chemicals. So some of them could be getting through in the drinking water, as well.
IRA FLATOW: And so this is– in how many places did they say– 35 bodies of water?
SOPHIE BUSHWICK: Right.
IRA FLATOW: And so it’s all over the place.
SOPHIE BUSHWICK: Yeah, Yeah. They were testing a bunch of different bodies of water, and some of them in rural areas, some of them in urban areas, and then some of them farther away from human habitation. And they found–
IRA FLATOW: And there must be stuff they didn’t test for that’s out there?
SOPHIE BUSHWICK: Absolutely. There’s thousands of chemicals that they didn’t test for that could be present.
IRA FLATOW: Wow. You also have a related story that’s quite interesting about road salt.
SOPHIE BUSHWICK: Mm-hmm. So this was another study where they tested the water in lakes. And in this case, they were looking at lakes to see if they were getting saltier over time. And they found that if the lake– if 1% of the area around that lake had been paved, it was very likely that it was getting saltier. And the problem is, when it’s winter, people put salt on the roads to prevent ice from forming, and that’s getting washed into these lakes, and it could be causing problems because at a certain level of saltiness, plants and animals– native plants and animals to those lakes might not be able to survive.
IRA FLATOW: Not to mention what the salt is doing to your lawn, but that’s a different–
SOPHIE BUSHWICK: Yeah.
IRA FLATOW: In your garden, that’s a different situation. Let’s move on to there’s new work on ants as farmers.
SOPHIE BUSHWICK: The story is actually really cool. So it turns out ants have been farming fungus. They bring fungus into the nest, and they feed it on things like leaves, and then they eat the fungus when it’s grown. And they’ve been doing this for 65 million years. And researchers knew at some point, in that 65 million years, the fungus and the ants began evolving. So that in some species, the ants require a chemical– they require an amino acid that only the fungus makes. And the fungus can’t live without the ants to feed them. So researchers wanted to find out where and when did this happen, and they traced it back to a point 30 million years ago when ants and the fungus were living in a desert environment.
So for the fungus being above ground in the dry desert air was not very– was not a friendly environment for them. So they were thriving underground in the ants’ burrows where it was more moist, and where the ants could tend them. And that’s where they think the evolutionary change happened that made the ants and the fungus dependent on each other. And then the ants probably went back to their jungle environment, brought the fungus with them, and now they have this symbiotic relationship.
IRA FLATOW: Maybe that’s where the term, “there’s a fungus among us” came from, living with the ant.
SOPHIE BUSHWICK: Yeah. The ants could definitely say to each other that they have “a fungus among us.”
IRA FLATOW: Sorry, it’s the weekend. Finally, you have a story about a newly discovered shrimp that’s definitely not silent, but deadly.
SOPHIE BUSHWICK: This is an amazing animal. It’s a type of pistol shrimp, so it’s kind of like a cousin to the mantis shrimp, which is the shrimp that can punch really hard. But this shrimp has one very large pink claw, and it uses this claw to make a noise that can beat 210 decibels. That’s loud enough to stun or even kill fish. Compare it to a rock concert– rock concerts will get up to about 120 decibels, so this can make noise so much louder than that. And because of the noise, and because of the pink claw, researchers have named it after Pink Floyd.
IRA FLATOW: Is that really– it’s the name of the shrimp?
SOPHIE BUSHWICK: It’s– they have it– there’s the genus name, and then the species name is pinkfloydi.
IRA FLATOW: Pinkfloydi. Any other shrimp or animals that come like that?
SOPHIE BUSHWICK: I mean there’s–
IRA FLATOW: Rockstars or?
SOPHIE BUSHWICK: There’s definitely other shrimp that can make really loud noises underwater. I mentioned the mantis shrimp. Because they punch so fast, it changes the pressure in the fluid around them, and then it creates these sort of pockets that implode. And so the mantis shrimp also makes a really loud noise. I don’t know that you’d want to rock along to it but–
IRA FLATOW: I actually used to have a little aquarium– I used to have a little reef aquarium in my living room. And I used to have a mantis shrimp in it, and you could hear it. It would– it was really– like when you don’t know, it’s clicking and whatever, in nighttime, the lights are out, it turns out it’s the shrimp that’s, I think, almost breaking the sound barrier.
IRA FLATOW: Yeah. Thank you. Thank you. Sophie Bushwick, senior editor at Popular Science. Thanks for being with us today.
SOPHIE BUSHWICK: Thanks for having me.