Florida's coral reefs are critical to the state's economy. They protect beaches and are vitally important for thriving fisheries.
But you may not have much time to see some types of live coral in the Florida Keys.
A severe heat wave killed many species in the summer of 2023, and stony coral tissue loss disease has also been particularly wiping out Atlantic pillar coral.
The pillar coral has decreased by 97% in Florida’s Coral Reef over the past decade with only 24 living colonies remaining.
Keri O'Neil, the director and a scientist for Florida Aquarium's coral conservation program, said it's the most threatened coral species in the state.
"Between disease and bleaching, we've had a lot of coral mortality over the past 10 to 15 years," she said.
So now, O’Neil is teaming up with researchers from around the globe — Mexico, Australia, Hawaii, and a scientist from the University of South Florida — to freeze, or “cryopreserve,” pillar corals in their larval stage, using liquid nitrogen in hopes of preventing their extinction.
"If we freeze those by tens of thousands, that's potentially tens of thousands of corals that can be thawed out and then grown," O’Neil said.
"We can go plant corals back on the reefs now, but we don't know what's going to happen in the next five, 10, 20 years, and a lot of the corals that get planted back out on the reef, they might not make it. And by freezing these larvae, they can be held for literally hundreds of years."
And generations from now, she said, she’s hopeful they can be thawed, grown in the lab and planted on the reefs. The big goal is to create a frozen gene bank.
“By freezing the larvae, we're really preventing extinction. And you know, that's critical for future coral restoration.”Keri O'Neil, Florida Aquarium
This freezing method has really only been commonly used on coral sperm or a pieces of tissue.
“But for corals, this the cryopreservation science is really in its very early stages,” O’Neil said.
The team has been trying to prevent ice crystals from forming inside the larvae, which would effectively ruin the process, by using chemicals called “cryoprotectants.” They’ve been using pipettes to transfer the larvae into petri dishes and inserting a stainless-steel mesh that allows the larvae to warm much more rapidly after they're frozen.
Then they get dipped into the liquid nitrogen.
“Which of course, makes this plume of what looks like smoke, and then trying to warm them up again and see if they're swimming. So, it's really been a team of about eight or nine of us huddled around a massive table, like looking on the microscope, pipetting larvae, trying to freeze them, testing the different chemicals, certain people, taking notes,” said O’Neil.
The next step for this project, she said, is to figure out how to scale up the process since the international coral problem is so immense.
The group of scientists hope to publish the results from the past weeks, but also continue experimenting the next couple years through a grant received from the Coral Research and Development Accelerator Program.
“By freezing the larvae, we're really preventing extinction. And you know, that's critical for future coral restoration,” said O’Neil.
