Short Wave - Seaweed is piling up on beaches. This robot might be its match

Episode Date: October 2, 2023

A new robot is designed to sink sargassum before the stinky seaweed comes ashore. Blooms of sargassum, a leafy brown seaweed, have increased in size and number over the past decade. As the blooms have grown, so too has their impact on coastal communities. The stinky seaweed can wreck local economies and ecosystems — and even threaten human health, some research suggests. But the creators of the AlgaRay say that their robot might do more than halt this damage. It could also fight climate change.This week NPR is doing something new — dedicating an entire week to stories and conversations about the search for climate solutions. Head to npr.org/climateweek for more stories of solutions.Have a science query? Email us at [e-mail] — we'd love to know!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

You're listening to Shortwave from NPR. Hey there, shortwavers, Aaron Scott here, and this week, MPR is doing something new. We're dedicating an entire week to stories and conversations about the search for climate solutions. And we're kicking the week off with our colleague reporter Emily Olson. Hey there, Emily. Hey, Erin. So what do you have for us today? I want to take you to a laboratory.

It's on the outskirts of Glasgow, Scotland. It's a rainy September morning, and there's a few engineers standing around an above-ground swimming pool. You know, like the hard plastic kind you might find in someone's backyard. All along the top of the water are rubber duckies. You mean like the bath toys? Yeah, absolutely. They're an important part of what's about to happen. See, the team is testing out an aquatic robot.

The Al Gore-A is our submersible, and it's designed to be a fully independent glider. That's Patty Estridge. She's the CEO of Seaweed Generation and the woman who had the idea to create this thing. Right now, the Al Gore-A, you can picture it, it's just a wire-framed metal box, but one day it'll have wings on the side, hence the name Al-Guray, it'll be in the shape of a Manta ray, and it'll be over 30 feet long. Right now, it's so heavy that the team has to use ropes and pulleys to heave it into the water. But once it's in the water, they can take it through a series of tests. So I'm just going to test the operation of the thrusters now. Most importantly, they're checking that it can slowly scoop up those rubber duckeys and sink them. Like, take them

all the way down to the bottom of the pool. Right, because cleaning up rubber duckeys is a significant global issue in need of a fix. Although, I guess that's not actually a joke. Is she working on the Great Pacific Garbage Patch? Right. No, these rubber ducies are just a stand-in for what's going to be the Al-Garay's eventual target. So the potential for the Algaray, we think, is to be able to massively reduce the sargasm in fluxes in the whole of the Great Atlantic Sargazum belt. Sargasm. That is the giant floating blobs of seaweed that are washing up on beaches and making a stinking mess, correct? Yeah, exactly. It's a type of algae. It kind of looks like a bunch of grass with a few pepods of air thrown in. Those keep it buoyant. And this algae clumps up

together and it floats around the North Atlantic and the Caribbean Sea in these little rafts, like these little patches. And we covered this earlier this year. I mean, this is an annual phenomenon that comes and goes every year. The Sargazem grows really big in the spring and then it dies off in the winter. Yeah, true. There's nothing new about Sargazem. It's been around forever.

But since 2011, the overall amount of Sargazm has been increasing. Look at this year's bloom, for example. At its peak, it weighed 13 million tons. It snaked from West Africa to the Gulf of Mexico over 5,500 miles long. I mean, that's bigger than the width of the United States. Holy moly. Talk about a super bloom. So is this bad?

Yeah, I mean, this is a relatively new phenomenon, and there's a lot we don't know. But in the open ocean, Sargazem appears to be kind of harmless. I mean, it might even be a net good for the environment. It seems to be a great habitat for fish and birds. But when it comes to... close to the shore like it's been doing often in the Caribbean islands at Florida, I mean, it can wreck local economies, absolutely destroy local ecosystems, and maybe even threaten human health. So today on the show, why an aquatic robot might be a solution to this toxic menace.

And why the company that built it thinks there might be an added benefit, fighting climate change. You're listening to Shortwave from NPR. Okay, Emily, let's take a step back to beginning. begin. Why is sarcasm taking over the Atlantic Ocean now? Well, Aaron, we don't know. I mean, these monster blooms are relatively new, so it's still early days for zeroing in on the causes. But what we do know is that as more sarcasm grows, more of it is washing ashore. And so more and more people are wondering, you know, what can we do about it? Right, because it is inundating coastal ecosystems and communities. Definitely. I mean, when sarcasm comes into shallow waters, it starts

to smother local coral reefs, mangroves, seagrasses, it can alter pH levels in the water, and that can suffocate marine life. You know, and that's not all. Like, if you're a human on a boat, algae might get into your motor or your propeller, you might get stuck for a while, and if you fish for a living, you could lose a lot of money. Okay. And in some places, it's even mucked up basic life necessities. Once Sargazim clogged a desalination plant in the U.S. Virgin Islands, and people didn't have safe drinking water. And then I've seen photos and videos of what it's like when it actually washes the shore and it piles up in the beach and starts to decay and looks truly disgusting. Yeah.

When it decays, it releases hydrogen sulfide. So you're saying the beach smells like rotten eggs. Uh-huh. And what happens when the beaches smell like that? Tourists stay away and that wrecks the economy. But, you know, it's more serious. We're also learning that Sargazm might pose a danger to human health. Interesting.

Like from the fumes? Yeah, it could be the fumes or, you know, more studies are showing that sargasm might contain heavy metals like arsenic. And some researchers say that that might be leaching into the groundwater. Back in 2018, there was one period of intense buildup on the islands of Guadalupe and Marnik. And doctors said there were over 8,000 cases of something they were calling acute sargasm toxicity. I mean, here's how one teacher describes sargasm season in St. Lucia and what it does for her students. fidgeting, and many, if not all of them, become very unsettled, making complaints that they're not feeling well, that they have headaches. Some even say that they have to throw up. Wow. She was one of dozens of people who came to a sargasm conference this year to raise awareness about what it's doing. And other speakers mentioned that they were losing sleep, feeling dizzy, developing rashes. It's bad. Emily, yeah, this, it sounds horrible. Our community's able to clean the sargasm up when it's piling up on the beach.

to prevent all these problems then? Yeah, a lot of them try to. But remember, this is thick and clumpy. It's not easy to move. So that means they usually have to bring in heavy equipment, and that costs a lot of money. And some places can't afford to get, you know, a dozen bulldozers for a month,

let alone every year again and again. Yeah, and beaches probably aren't the best place to be driving bulldozers around anyway. Exactly. They can worsen shoreline erosion, plus, you know, they can squash turtle nests. Poor turtles. Okay, so Emily, we have established the problem.

Is this where our rubber-ducky scooping robot comes in? Bingo. The company making this robot says, you know, maybe the best option for Sargazum is just to sink it. Uh-huh. The idea is the Algaray, this solar-powered, autonomous submersible. It would intercept the patches of seaweed before they come ashore. Then it would take it back out into the open ocean,

dive down to depths of 150 or 200 meters and pop the AirPods that keep the Sargazum afloat. Very cool. And as Patty puts it, the Al Gorey is a bit like a Pac-Man meets a Roomba for Sargazum. I love that image. Sold. So I guess the next question is, who's going to pay for this? I mean, you mentioned earlier that the cost of cleaning Sargazum isn't cheap, so somebody's got to pay for these robots. Yeah. Right now, seaweed generation, it's a startup. So it's funded by venture capitalists.

And the company says they've seen a lot of interest from local governments and hotel groups that might want to buy and operate their own algorithms in the future. But Patty told me, you know, there's also another stream of revenue that they could see working out in the long term future. We are selling carbon dioxide removal credit for sinking salgatum to corporations with net zero goals. Right, right, right, carbon credits. This, of course, is one way that some corporations are trying to limit the warming of our atmosphere to 1.5 degrees Celsius above pre-industrial levels in order to avoid the most catastrophic effects of climate change. Yeah, some corporations, they try to offset their own emissions by buying credits that fund projects to remove carbon from the atmosphere. So, you know, a company could pay to protect part of a forest. And the idea is that sort of cancels out some of their own polluting emissions. And of course, this is an entire can of worms.

There are critics who say that a lot of these carbon credits are failing to deliver on what they promise. But that controversy aside, is the idea here that the Alga Ray will sink the sargasm and the then that is basically pulling all the carbon inside of that algae down to the bottom of the ocean and leaving it there. Yeah, that's the idea. I wanted to know if it would actually work. So I talked to Ajit Sopermanian. He's an oceanographer with Columbia University.

And he says already the ocean is pretty good at storing carbon. Our current models of ocean circulation basically tell us that if you go below about 2,000 meters, then you are not going to come back to the atmosphere. at least 100 years. So in theory, seaweed looks like a pretty reliable vessel for carbon storage. I mean, you can compare it to, say, planting a bunch of trees, which might burn down. But there's still two questions here. One is, will it actually sink sargasm that naturally wouldn't sink on its own?

And scientists aren't sure about that. Like, they're not sure how deep sargasm sinks when it dies in the wild. They still need more studies. The second question is, you know, can this robot actually do enough to make a meaningful difference? Right. Like how much sargazim can one algaeray sink? So the company says when it's fully up and running, if one Algaray is working three months out of the year, 12 hours every day, that alone could sink about 80,000 tons of sarcasm a year. And that translates to 8,000 tons of carbon dioxide. And is that a lot? Well, let's compare it to the world's largest direct carbon capture facility. That's in Iceland. It's still being built. But right now,

when it's up and running, that facility is only capturing about half of what this company is saying that the Al-Gray could potentially do. Which is not bad for one little Sargazim Rumba. Yeah, totally. But let's level set here. I mean, even that big fancy Iceland facility, that will just capture one 10,000th of one percent of what humans emit annually. Wow. I mean, one Al-GRA can't reverse climate change. But of course, there could be more Al-GRAs working together, but we don't know what could happen if we start sinking, you know, half or even one-tenth of all the sarcasm that's in the wild, that much might start to be harmful to all the marine life that's starting to take up a home, you know, there in those patches. Right, right. So still a lot of questions unresolved. Yeah. And to be

fair, I think seaweed generation is very clear-eyed about the unknowns, and they're fine with being a test case. They want to see this as a window into researching, sinking biomass as a whole. But when I asked Patty about the Al Gray's potential, she phrased it this way. To help us understand whether seaweed as a larger concept can be viable for large-scale carbon dioxide removal, but we're pretty excited about just being able to alleviate the problems on the coast and solve some of the ecological problems that are being caused by the influxes at the moment. And they still got some time. I mean, she thinks it'll be about 18 months until this prototype will be even ready to work reliably in the wild. So like everything else in this climate

emergency, even figuring out the solutions, it takes time. Thank you for bringing us this story on one climate solution, Emily. No problem. Emily's reporting on the Al Gorey Robot is part of MPR's Climate Week, and you can head to mpr.org slash climate week for more stories exploring solutions like this one. This episode was produced by Burley McCoy and Rachel Carlson, edited by our managing producer, Rebecca Ramirez and Andrea Kisick and fact-checked by Emily. The audio engineer was Robert Rodriguez. Beth Donovan is our senior director and Anya Grundman is our senior vice president of programming. I'm Aaron Scott. Thanks for listening to Shortwave from NPR.