CNN Exclusive: Scientists make major breakthrough in race to save Caribbean coral

Sep 5, 2022, 7:00 AM

Just as other vital coral ecosystems are degrading around the world, elkhorn are now rarely seen al...

Just as other vital coral ecosystems are degrading around the world, elkhorn are now rarely seen alive in the wild (CNN).


(CNN) — Scientists at the Florida Aquarium have made a breakthrough in the race to save Caribbean coral: For the first time, marine biologists have successfully reproduced elkhorn coral, a critical species, using aquarium technology.

It’s a historic step forward, and one they hope could help revitalize Caribbean ecosystems and could pay humans back by offering extra protection from the fury of hurricanes.

Elkhorn coral once dominated the Caribbean. But, just as other vital coral ecosystems are degrading around the world, elkhorn are now rarely seen alive in the wild. This species — so important because it provides the building blocks for reefs to flourish — has been until now notoriously difficult to grow in aquariums.

Which is why scientists were thrilled when they saw their reproductive experiment was a success.

“When it finally happened, the first sense is just sheer relief.” said Keri O’Neil, the senior scientist that oversees the Tampa aquarium’s spawning lab. “This is a critical step to preventing elkhorn coral from going extinct in the state of Florida.”

O’Neil’s colleagues call her the “coral whisperer” because she has managed to spawn so many varieties of coral. Elkhorn marks the aquarium’s 14th species spawned inside the Apollo Beach lab, but the team ranks it as its most important yet.

O’Neil estimates there are only about 300 elkhorn coral left in the Florida Keys Reef Tract — but the spawning experiment produced thousands of baby coral. She expects up to 100 of them could survive into adulthood.

Named for its resemblance to elk antlers, the coral thrives at the top of reefs, typically growing in water depths of less than 20 feet. This makes their colonies crucial for breaking up large waves. During peak hurricane season, reefs are a silent but powerful ally that protects Florida’s coastlines from storm surges, which are growing larger as sea levels rise.

“As these reefs die, they begin to erode away and we lose that coastal protection as well as all of the habitat that these reefs provide for fish and other species,” O’Neil said. “Now there are so few left, there’s just a few scattered colonies. But we’re really focusing on restoring the elkhorn coral population for coastal protection.”

The Florida Aquarium’s news comes after scientists reported in early August that the Great Barrier Reef was showing the largest extent of coral cover in 36 years. But the outlook for coral around the world is grim — studies have shown that the climate crisis could kill all of Earth’s coral reefs by the end of the century.

Elkhorn coral was listed as federally threatened under the US Endangered Species Act in 2006 after scientists found that disease cut the population by 97% since the 1980s. And ocean warming is its largest threat. As ocean temperature rises, coral expels the symbiotic algae that lives inside it and produces nutrients. This is the process of coral bleaching, and it typically ends in death for the coral.

“They’re dying around the world,” O’Neil told CNN. “We are at a point now where they may never be the same. You can’t have the ocean running a fever every summer and not expect there to be impacts.”

‘You know that’s impossible’

Elkhorn coral seem to have something analogous to a fertility problem. Its reproduction is sporadic in the wild, making it difficult to sustain a much-needed increase in population. Because of its low reproductive rate, genetic diversity can also be very low, making them more susceptible to disease.

“You could say they’re successfully having sex, but they’re not successfully making babies [in the wild],” O’Neil said. “Terrestrial animals do this all the time. When you have an endangered panda or chimpanzee, the first thing you do is start a breeding program, but coral reproduction is super weird.”

The most challenging part for O’Neil’s team was doing the unprecedented — getting the coral to spawn in a lab. O’Neil said other researchers doubted they could pull it off.

“We faced a lot of criticism from people,” she said. They would say “‘you can’t keep those in an aquarium. You know that’s impossible!'”

They were right. At first.

Elkhorn coral only spawn once a year. In the lab’s 2021 experiment, the environment was strictly controlled to imitate natural conditions. Using LED lights, they accurately mimicked sunrise, sunset and moon cycles. But the coral didn’t spawn.

We “realized that the timing of moonrise was off by about three hours,” O’Neil said.

After that frustrating failure, the aquarium’s scientists knew they had a much better shot this year. And, with support from the National Oceanic and Atmospheric Administration Restoration Center and the National Fish and Wildlife Foundation, the Florida Aquarium did in August what was thought impossible by some peers.

The spawning could be a game-changer, according to Thomas Frazer, the dean of the College of Marine Science at the University of South Florida, and it could lead to a future where coral is more resilient to the dramatic changes brought by the climate crisis.

“This type of work really matters,” Frazer told CNN. “Corals selected for restoration might, for example, be more resistant to warmer ocean temperatures and bleaching, exhibit skeletal properties that are able to withstand more intense wave energy, or traits that might make them more resistant to disease or other environmental stressors.”

Margeret W. Miller is a coral ecologist who has focused on restoration research for more than two decades. Miller co-authored a study in 2020 that found the elkhorn rate of reproduction in the Upper Florida Keys was so low, it would indicate the species was already “functionally extinct” and could be wiped out in six to 12 years.

Miller said the Florida Aquarium’s breakthrough will open new doors to tackle the larger restoration effort.

“Because this species is an important restoration target, the capacity for spawning under human care opens lots of research opportunities to develop interventions that might make restoration efforts more resilient to climate change and other environmental threats,” Miller told CNN.

Miller said more research needs to be done to make sure lab-spawning elkhorn coral is reasonably safe and effective, to be used in species conservation.

“This sort of captive spawning is not a tool that directly addresses widespread coral restoration at the global scale that would match the scale of the need. Indeed, no current coral restoration efforts meet that scale, and none will truly succeed unless we can take serious action to ensure that coral reef habitats can remain in a viable condition where corals can thrive,” Miller told CNN.

The climate crisis is the ultimate problem that needs to be solved, Miller said. The rapid increase in ocean temperature needs to be addressed, along with threats to water quality. Still, she said, the ability to grow elkhorn in a lab is an important tool in the restoration effort.

“The research on coral propagation and interventions that can be enabled by captive spawning efforts can, however, buy time for us to make such changes effectively before corals disappear from our reefs completely,” Miller said.

Buying time

Elkhorn branches can grow as much as five inches per year, making it one of the fastest-growing coral species, according to NOAA. And based on observations from the Florida Aquarium scientists, their new elkhorn coral babies will take three to five years to become sexually mature.

Within a year or two, scientists intend to replant these lab-grown corals in the Florida Keys National Marine Sanctuary.

In the race to restore the reefs, scientists agree this breakthrough is only a first step.

“We are really buying time,” O’Neil said. “We’re buying time for the reef. We’re buying time for the corals.”

The ultimate goal is a breeding program where scientists could select for genetic diversity and breed more resilient coral capable of withstanding threats like pollution, warming ocean waters and disease.

Then nature can take the wheel.

“There is hope for coral reefs,” O’Neil said. “Don’t give up hope. It’s all not lost. However, we need to make serious changes in our behavior to save this planet.”


We want to hear from you.

Have a story idea or tip? Send it to the KSL NewsRadio team here.


Senate Minority Leader Mitch McConnell (R-KY) heads to the floor of the Senate for a vote on Capito...

Clare Foran, Morgan Rimmer and Ted Barrett, CNN

Mitch McConnell to step down from GOP leadership position in the Senate

Mitch McConnell will step down as GOP leader in November, the Kentucky Republican announced on the Senate floor Wednesday.

5 days ago

Soldiers carry the coffin of Ukrainian poet and serviceman Maksym Kryvtsov who was killed in action...

Stephanie Halasz and Ivana Kottasová, CNN

Zelensky warns ‘millions will be killed’ without US aid to Kyiv, as Ukrainian troop deaths reach at least 31,000

“Millions” could die in Ukraine’s war with Russia if US lawmakers don’t approve President Joe Biden’s $60 billion aid request.

8 days ago

Kathy Brandel and her husband of 27 years, Ralph Hendry...

Sharif Paget, Chris Boyette and Polo Sandoval, CNN

Family of Americans believed dead after yacht allegedly hijacked in Grenada describe scene of violence

The family of two Americans who may have been killed in an alleged yacht high jacking in Granada hope the couple might be found alive.

8 days ago

Police tape drapes the crime scene on a trail behind Lake Herrick at the University of Georgia in A...

Ashley R. Williams, Raja Razek, Priscilla Alvarez, Isabel Rosales and Jaide Timm-Garcia, CNN

Questions remain in investigation of death of Augusta University student found on UGA campus

As the investigation continues into the death of an Augusta University student, officials confirmed the immigration status of a suspect.

8 days ago

Kenneth Mitchell, here in 2018, has died....

Megan Thomas, CNN

Kenneth Mitchell, ‘Star Trek’ and ‘Marvel’ actor, dead at 49

A native of Canada, Mitchell acquired more than 50 film and television credits over the course of his acting career. He was diagnosed with ALS in 2019.

9 days ago

Charles E. Escalera, 21...

Michelle Watson and Maria Sole Campinoti, CNN

Kentucky man arrested in connection with death of Campbellsville University student

A man has been arrested in connection with the death of a student at Campbellsville University in Kentucky.

9 days ago

Sponsored Articles

Mother and cute toddler child in a little fancy wooden cottage, reading a book, drinking tea and en...

Visit Bear Lake

How to find the best winter lodging in Bear Lake, Utah

Winter lodging in Bear Lake can be more limited than in the summer, but with some careful planning you can easily book your next winter trip.

Happy family in winter clothing at the ski resort, winter time, watching at mountains in front of t...

Visit Bear Lake

Ski more for less: Affordable ski resorts near Bear Lake, Utah

Plan your perfect ski getaway in Bear Lake this winter, with pristine slopes, affordable tickets, and breathtaking scenery.

front of the Butch Cassidy museum with a man in a cowboy hat standing in the doorway...

Bear Lake Convention and Visitors Bureau

Looking Back: The History of Bear Lake

The history of Bear Lake is full of fascinating stories. At over 250,000 years old, the lake has seen generations of people visit its shores.

silhouette of a family looking over a lake with a bird in the top corner flying...

Bear Lake Convention and Visitors Bureau

8 Fun Activities To Do in Bear Lake Without Getting in the Water

Bear Lake offers plenty of activities for the whole family to enjoy without having to get in the water. Catch 8 of our favorite activities.

Wellsville Mountains in the spring with a pond in the foreground...

Wasatch Property Management

Advantages of Renting Over Owning a Home

Renting allows you to enjoy luxury amenities and low maintenance without the long-term commitment and responsibilities of owning a home.

Clouds over a red rock vista in Hurricane, Utah...

Wasatch Property Management

Why Southern Utah is a Retirement Paradise

Retirement in southern Utah offers plenty of cultural and recreational opportunities. Find out all that this region has to offer.

CNN Exclusive: Scientists make major breakthrough in race to save Caribbean coral