Toxic algae season is back — and Trump has cut safeguards

Last August, I was standing on Lake Erie’s Ohio shore, shielding my eyes from the sun while talking to a middle-aged guy wearing swimming trunks and a shell necklace. He had to be Toledo’s only surfer. 

“Are you worried about the algae at all?” I asked him.

“No. I was out Monday, and I didn’t see any algae. If it’s bad, it looks like pea soup.” He pulled a couple of windsurfing boards from the back of a pickup and began explaining the finer points of a northward versus a westward wind. That day, a breeze smelling a little earthy and mulchy was coming from the west, which wasn’t as good for surfing. 

Wind direction seemed like his biggest worry at the time — even though the entire lake had turned light green. Slime was gently lapping ashore just a few feet away. 

“So, this isn’t toxic algae?” I said.

“Nah, that’s just the sun,” he said, implying, I guessed, that this was just regular algae. 

But I wasn’t so sure. A huge wooden sign was staked into the sand that warned people to:

BE ALERT! AVOID WATER THAT:

• Looks like spilled paint.
• Has surface scums, mats, or films.
• Is discolored or has colored streaks.
• Has green globs floating below the surface.

AVOID SWALLOWING LAKE WATER.

Below these warnings were eight images of various waterborne funk and deformity, each about as pleasant as an autopsy photo.

“There’s no danger of getting sick from the algae?” I asked, a little wary.

He laughed. “We’re gonna find out.” 

This year, things on Lake Erie aren’t any better. And chances are, if you live near a body of fresh water, you might be experiencing that same strange seasonal sight that is fast becoming as normalized as orange leaves in October and pink flowers in April: Neon green toxic algae. Despite what your local windsurfer might say, global warming, pollution and government inaction have combined to create this dangerous — even deadly — threat to our drinking supply and recreational spots. If you are lucky enough that this cyanobacteria, or kale-colored gak, has not yet infected your local lakes, bays, rivers or creeks — well, it probably will be soon.

Recently, this sleepy, rural part of Ohio I was raised in has been receiving global attention as ground-zero for an eye-popping upheaval of nature. But it’s also quietly becoming the unlikely home of a Hail Mary opportunity to reverse this ecological disaster. 

I spent the last five years researching this phenomenon for my upcoming book, “The Great Black Swamp: Toxic Algae, Toxic Relationships, and The Most Interesting Place in America Nobody’s Ever Heard Of.” So I was not surprised when The Toledo Blade reported that only four days into August, this green cyanobacteria bloom was already 160 square miles in size — that’s over half as large as New York City — and getting bigger. “The main part of the algal bloom can be seen from outer space,” the article read.

Believe it or not, this is far from Lake Erie’s biggest or most dangerous bloom. In August 2014, Toledo’s shoreline turned margarita green. Dead fish began washing ashore in clumps, all tangled in thick mats of toxic algae. Overnight, the plume spread to the city’s drinking water intakes, and 400,000 Toledoans were told to not drink or cook with tap water, or even bathe with it. 

The lake’s microcystin levels registered a whopping 2.5 parts per billion. (Microcystins are toxins produced by the algae.) According to the World Health Organization, just one part per billion is considered unsafe to drink. One scientist noted that the town’s drinking water was currently “more toxic than cyanide.” If ingested, it could cause nausea, vomiting or diarrhea, and drinking a single glass could result in liver failure. Death was uncommon, but it had been known to happen. A herd of rare elephants in Botswana died from drinking from toxic algae puddles, 50 people in Brazil died after microcystin-laced water was used in their hospital IVs and an entire family and their dog were found dead on a Yellowstone hiking trail after swimming in an algae-plagued creek. 

By the end of the third day of the water ban, using a $4 million mix of aluminum and chlorine, Lake Erie was shocked like a pool back to safe levels. Now, because bright green algae keeps reappearing every year around this time, Toledo must always be prepared for such outbreaks. 

The city’s harrowing crisis was one of the first times toxic algae took center stage in the media cycle. But the way things are trending, it won’t be the last. Earlier this year, an “unprecedented” toxic algae bloom along the coast of Southern California caused hundreds of marine mammals to become sick or die. The problem has become so widespread that the U.S. National Office for Harmful Algal Blooms estimated that the United States spends upwards of $50 million annually in costs related to health, fisheries, recreation, tourism and monitoring. The EPA reported 15,000 bodies of water with algae-like nutrient problems in 2023 alone, and all 50 states have had a toxic algae outbreak, usually more than one. 

Harmful algal blooms have been reported on every continent except Antarctica. According to Scientific American, in the last two decades algal blooms have increased in size by about 13% worldwide, which means if you cobbled them all together, the blob would take up about as many square miles as the entire nation of India. 

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All indications seem to imply it’s only going to get worse. That’s because the source of this growing threat is ubiquitous around the globe. In the case of Lake Erie and many other bodies of water, toxic algae forms due to a combination of phosphorus-rich farm runoff meeting rising water temperatures due to climate change. (Water temperatures usually peak in August.) Since 2014, Ohio’s efforts to curb these yearly explosions have proven depressingly insufficient. Farmers have scaled back on phosphorus-rich fertilizer usage, and after Toledo established the Lake Erie Bill of Rights in 2019, the body of water was even briefly granted the same rights as a human being, which made polluting its waters a crime along the lines of attempted manslaughter. (The bill was quickly struck down in court.) 

Yet toxic algae keeps returning. Ecologists have begun ringing alarm bells after the Trump administration drastically scaled back environmental safeguards and regulations, like the Department of Government Efficiency’s proposed cuts, which include slashing 65% of Environmental Protection Agency spending and a proposed 25% cut to the National Oceanic and Atmospheric Administration, the agency responsible for monitoring and warning people about toxic algae blooms. 

By now, you might be feeling pretty frustrated and more than a little leery about what’s pouring out of your kitchen faucet. (To be clear, most drinking water is monitored by municipal treatment professionals, who do a great job of keeping people safe, but they are fighting an increasingly uphill battle.) I felt the same way when I went to Toledo last year and left feeling pretty helpless. Then, I discovered Lake Erie’s last hope. 

Several groups in Northwest Ohio are eschewing legal and chemical methods and are, instead, trying to save the lake by going back to the dark ages — literally. The region was once known as the Great Black Swamp, a one million acre wetland the size of Connecticut so densely filled with trees that some explorers claimed they couldn’t see their hand in front of their face during the day, hence the name. According to these organizations, the answer to reversing toxic algae lies in Ohio’s swampy past. 

Organizations like The Black Swamp Conservancy and H2Ohio, which is run by the state, are purchasing tracts of farmland near freshwater bodies and rewilding these places. By removing the drainage tiles buried underground and replanting native trees, wildflowers and grasses, they are strategically turning these parcels back into wetlands. The theory, as a conservation manager told me at one rewilding site last year, is that wetlands act as a set of kidneys for the land, naturally filtering out much of the phosphorus from farm runoff, which causes toxic algae. Between the two organizations alone, nearly 35,000 acres of land have already been restored. But to truly make an impact on Lake Erie, they will need to expand their efforts.

The odds of improving the lake’s toxic algae problem are good if they can keep growing. That’s because rewilding works. A similar effort has already shown great success. In 2024, a team of Bowling Green State University biology students recorded a significant reduction in cyanobacteria in Northwest Ohio’s Sandusky Bay thanks to the removal of an upstream dam. While this is only a small victory, it is proof there is still hope for Lake Erie’s water, and also for the water near you. 

I don’t know what happened to the windsurfer on Lake Erie last year. I didn’t stick around to watch him cruise the westward winds. He could have been totally fine, or he could have gotten deathly ill. All I know is that I don’t want to think like him. Sure, it would be a lot easier to treat these ecological horrors like the new normal, but we need to take matters into our own hands. If governments and the legal system won’t nurture these waters, we must seek out and support rewilding efforts on our own. The way things are going, that will likely be the only way to keep from one day pouring a cool glass of cyanide from our sinks.