Pilar Aguayo is a fictional marine biologist, invented for this column because the real people doing this work are too busy keeping things alive to sit for long interviews. But her world is built from theirs: the science is real, the losses are documented, and the questions she can't answer are the ones actual practitioners carry around every day. We made her up. We didn't make up the reef.
The coral nursery at Summerland Key smells like salt and warm PVC. It's 6:40 AM and already 84 degrees, a temperature that a decade ago would have been a July afternoon. Pilar Aguayo is elbow-deep in a fiberglass raceway, adjusting the flow rate over a tray of staghorn fragments no bigger than her thumb. Twenty of these tanks sit in rows behind her, producing somewhere between six and ten thousand fragments a year.1 A whiteboard lists genotype codes in four colors of dry-erase marker. She's explained the color system twice. I still don't follow it.
Aguayo left a postdoc at the University of Miami's Rosenstiel School seven years ago to work in restoration full-time. She grew up in Key West. Her grandfather was a commercial fisherman who described the reef of the 1970s the way some people describe a first love, with a specificity that made her suspicious it had been embellished. Photographs confirmed it hadn't.
She dries her hands on a towel that says MOTE MARINE across it in faded blue letters and sits on an overturned bucket. She does not, at any point during our conversation, sit in a chair.
You've been doing this for over a decade. What does "this" actually look like now?
Pilar: When I started, the pitch was clean. Grow coral fast, plant coral on reefs, reefs recover. Grow, plant, monitor, repeat. CRF had the largest nursery in the world, forty-five thousand corals in the water.2 The logic was volume. Put enough out there, enough survives.
Then 2023 happened.
What broke?
Pilar: Water temperatures in the Keys hit levels we weren't supposed to see for another twenty years. On some of the Mission: Iconic Reefs sites, NOAA found ninety-five percent of the elkhorn dead.3 Ken Nedimyer described going out and seeing white coral everywhere, like a snowstorm. Two weeks later it was all gray. Twenty years of work gone in a week.4
And we lost massive nursery stock too. You can't evacuate forty-five thousand corals. There's nowhere to put them. That infrastructure simply doesn't exist at scale.5
So the whole approach pivoted. Phanor Montoya-Maya at CRF put it clearly: stop outplanting everywhere, go find the survivors, figure out why they survived.6 That's where we are now. Survivor intelligence.
She adjusts a flow valve without looking at it, the way you'd stir coffee.
That shift from volume to selection is essentially choosing which genetic lines get a future.
Pilar: That's exactly what it is. Nobody's fully comfortable with it. We tested two hundred and twenty-nine staghorn strains across South Florida programs, looking for heat tolerance.7 Real variation exists. Some strains handle the heat significantly better. So you propagate those. And the ones that can't take it, you're not actively killing them, but you're not investing in them either.
You're making a triage decision about the genome of a reef system.
Does that feel like playing god?
Pilar: It feels like being a very underfunded god with a budget spreadsheet. We need five million corals to hit the Mission: Iconic Reefs goal by 2040. In the first five years, we planted about forty thousand.8 Do the math on that gap and then come talk to me about guilt.
You've mentioned pivoting to different species entirely. Away from elkhorn and staghorn, toward brain and boulder corals.
Pilar: The massive species handled 2023 much better than the branching corals.9 Which makes sense physiologically. But emotionally it's a whole thing, because elkhorn and staghorn were the species. They built the reef structure. They're what my grandfather described. They're what's on the posters, on the dive shop logos, on every conservation brochure you've ever seen.
And now we're saying, okay, maybe the future reef is mostly boulder coral. Which is fine. It's alive. But it's a different animal. Literally a different animal.
There's also the cross-breeding work. Coral from Honduras, the Cayman Islands.
Pilar: Andrew Baker's program at Rosenstiel. Breeding Florida coral with coral from reefs that already tolerate hotter water.10 And the symbiont work might be even more radical. Richard Karp's team showed that elkhorn hosting a heat-tolerant algae, Durusdinium, could survive temperatures almost twenty degrees Celsius higher than elkhorn with the typical symbiont.11 That's not a marginal improvement. That's a fundamentally different relationship with heat.
Does that trouble you?
Pilar: [Long pause.]
Some days I think this is just evolution, accelerated. We're doing what the reef would do over centuries if it had centuries. Which it doesn't. WMO confirmed ocean heat content hit another record in 2025, warming rate more than doubled since 2005.12 The reef cannot adapt on its own timeline. So we help.
Other days I look at a coral fragment that's been inoculated with a symbiont it would never have encountered in the wild, bred from parents on two different reefs in two different countries, growing in a fiberglass tank in a parking lot in Summerland Key, and I think: What is this? Is this the reef? Or is this something new that we're calling the reef because we need it to be?
What would your grandfather say?
Pilar: He'd say it's not the reef. [Laughs.] Very politely. And then he'd go fishing.
But he watched the decline from the seventies onward. Ninety percent of the coral cover in the Keys, gone.13 He didn't have the luxury of pretending things stay the same. He fished different species in different places. He didn't call it adaptation. He called it Tuesday.
Mote has a gene bank now. A hardened facility twenty miles inland, redundant power, holding over sixteen hundred genotypes from seventeen species.14 What is that, to you?
Pilar: Insurance. That's literally what they call it. An insurance policy. And I'm glad it exists.
But there's something about storing a living reef in a building in Homestead. It's like keeping someone's voicemail after they die. It's them. It's not them.
You mentioned that Mote's restored corals spawned on the reef for the first time. Mountainous star coral reaching maturity in five years instead of decades.15 That seems like unambiguous good news.
Pilar: It is. Genuinely. That's the thing that keeps me in this work. When something you grew in a tank goes out on the reef and makes babies, that's not us anymore. That's the reef doing its own thing with what we gave it. That's the part I can't manufacture or select for.
That's the part that's still wild.
So is it the reef?
Ask me in twenty years. I'll be here.
She gets up from the bucket, pulls on nitrile gloves, and goes back to the raceways. The whiteboard behind her lists a hundred and ninety unique genotypes.16 Each one a bet on a future that hasn't decided yet what it wants to be.
Footnotes
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Mote Marine Laboratory operates land-based coral nurseries including fiberglass "raceways" producing thousands of fragments annually for outplanting. Mote Marine Laboratory, Coral Reef Restoration Program ↩
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NOAA Climate.gov, "The Future of Coral Restoration in the Florida Keys After Unprecedented Marine Heat Wave of 2023," May 2024 ↩
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NPR (Lauren Sommer), "Scientists are using corals from other countries to save Florida's dying reefs," Oct. 1, 2025 ↩
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University of Miami Rosenstiel School, "Scientists publish first large-scale census of coral heat tolerance," Oct. 2021 ↩
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NOAA Fisheries, "NOAA and Partners Launch Next-Generation Coral Restoration," Nov. 2025 ↩
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University of Miami Rosenstiel School, "Heat-tolerant symbionts a critical key to protecting Florida's elkhorn coral," May 2025 ↩
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WMO / Phys.org, "Planet trapped record heat in 2025," March 23, 2026 ↩