There’s a Silver Lining to the Reflecting Pool Fiasco

On June 5, workers began refilling the newly renovated Lincoln Memorial Reflecting Pool. By June 15, the water had been taken over by algae. You know the story: The pool got greener and greener. President Donald Trump, who had made the clarity of the Reflecting Pool a cornerstone of his summer plans, got madder and madder.

As Euan Reavie followed the news, he found himself put out, too—for a different reason. “I was so frustrated that no one had actually analyzed a sample,” he says. Reavie is a senior research associate at the University of Minnesota whose work centers around “algae as indicators of environmental changes.” While the Department of the Interior has said that they are testing the water, they haven’t publicly shared the results. So Reavie deputized a friend of a friend in D.C. to dip a vial into the green water and ship it to him overnight. Then he put it under a microscope, he says, “just to see what was in there.” The answer, for that sample, was: mostly Desmodesmus, a green algae that gobbles up phosphorus and nitrogen.

In the weeks since the Reflecting Pool’s makeover went south, many have seized what is a rich and slimy opportunity for metaphor. Commentators draw parallels with other intractable conflicts, and count the taxpayer money they say has spiraled down the drain. Protesters hold signs supporting “Team Algae.” A thousand memes have bloomed.

But one group is staying literal: the algae fans. They’re looking at the algae and seeing algae. And they’re hoping we can see it, too.

Although algae is rarely in the spotlight, it’s pretty much everywhere else. Worldwide, “there are probably over a million species,” says Reavie. The term is less taxonomically specific and more of a catchall, used to refer to any photosynthesizing organism that isn’t a plant. Where we might see unwelcome green goo, the Reavies of the world see “really interesting organisms” that are omnipresent, important, and full of information.

Algae can powerfully impact their surroundings, for good or ill. Reavie usually studies algae in the Great Lakes, where they make up the base of the freshwater food web, supporting an ecosystem that in turn supports a $5 billion fishing economy. The kelp that form vast underwater forests (and which manufacturers use to make fertilizer, and as a component of toothpaste and shampoo) are algae. So are the numerous organisms that create harmful algal blooms (or HABs), which can poison wildlife and humans.

But not all algae is like that. “People were making assumptions about it being toxic,” said Reavie about the Reflecting Pool algae. Desmodesmus is “not a dangerous thing,” he says, although in such large amounts, “it can be unsightly for sure,” as well as stinky.

He posted his microscope photos in a few places online, titling them “the people’s algae.” Algae-heads have flocked to the posts to share their own photos, hazard species-level identifications, and talk trash.

Some engaged in educated schadenfreude: “WAIT WAIT WAIT. It’s a [Desmodesmus] bloom??? Green algae is not … susceptible to hydrogen peroxide as a control method,” one redditor pointed out, referring to an attempt made to fight the algae. (In fact, according to the Atlantic, the hydrogen peroxide may have simply killed off blue-green algae, leaving room for Desmodesmus and related kinds of green algae to thrive.) Others were pulled back to their lab days: “Considering volunteering my services as I have unintentionally killed Desmodesmus cultures many times,” one scientist reminisced on Bluesky.

Others, it seems, wanted merch. When Annie Talley heard about the algae in the Reflecting Pool, she decided to honor it the best way she knew how: by creating a commemorative suncatcher that looks like a little Desmodesmus. She shared a photo in the Amateur Microscopy Facebook group she frequents, noting it’s “the most famous algae in the world right now!!”

Talley, an artist and retired college biology teacher, has—prior to the Reflecting Pool situation—made dozens of algae-themed suncatchers out of UV resin. While some of these creations have been commissioned by researchers, most hang in the window of her house. (Phycology, or the study of algae, is “really not that big of a field,” she says.) But her Desmodesmus photo has over 1,000 likes. “People are emailing me,” she says. “They want to buy them.”

Talley’s suncatchers dangle in the air and catch the light, an homage to algae’s most impactful contribution: producing over half of the world’s oxygen, which they do using energy from the sun.

“People think, ‘Oh, algae, it’s poison,’ ” she says. “But some algaes are good and some are bad.” Plus, up close, “they’re just beautiful,” she says.

Alongside the curiosity and wholehearted appreciation, these fans see another benefit of focusing on the algae: It leads to the truth. Trump has asserted that the algae’s pool takeover must be an act of vandalism. But anyone who knows about algae will realize that it didn’t need any help, Talley says. The seeds of this algae bloom could have come from the air, the rain, or the piped-in replacement water. And “if they fertilize the lawn around the pool, all that water that’s running in there is adding nitrogen and phosphorus,” she says. “That’s what they love.”

Reavie was careful to say that without ongoing monitoring, he could only guess why the algae arrived, and what might happen to it next. But the coat of dark paint certainly doesn’t help, he says: “The pool is going to be much warmer now throughout the summer, which is going to promote, potentially, blooms of algae that you really don’t want.”

Sign up for Slate's evening newsletter.