On any given day, aquarist Sara Stevens whips up a slurry of plankton, amino acids and other powdered nutrients to feed a voracious group of rescued corals. Using a turkey baster, she blasts the cloudy concoction over each colony made up of thousands of individual organisms called polyps, watching as their tiny tentacles slowly extend and envelop the meal. For the especially carnivorous ones housed at the Butterfly Pavilion in Westminster, Colo., she hand-feeds them full-bodied krill.
This ritual is just one part of the painstaking care Stevens and other aquarists across the country have been giving to a group of corals rescued from disease-ridden waters in Florida. Their future depends on it.
Since 2014, a mysterious illness known as stony coral tissue loss disease has plagued Florida’s reef tract, killing off nearly half the state’s hard corals, whose rigid limestone skeletons provide the architectural backbone of the largest bank reef in the continental United States. By 2018, it became clear that without drastic intervention, these corals would face imminent localized extinction.
“We couldn’t sit back and watch these corals disappear,” said Stephanie Schopmeyer, a coral ecologist from the Florida Fish and Wildlife Conservation Commission.
To save them, scientists devised a plan to remove the most vulnerable species from their natural habitat and create a land-based gene bank that would serve as a modern day ark for the animals. They knew that to succeed, time was of the essence and collaboration was key. What followed was an unprecedented effort, in which dozens of federal and state organizations, universities, zoos and aquariums joined forces to rescue thousands of Florida’s endangered corals.
Around 40 percent of Florida’s rescued corals remain local at the Florida Coral Rescue Center, a state-of-the-art facility created solely for the purpose of housing and restoring populations affected by stony coral tissue loss. But before the facility opened last year, rescued corals were flown across the country to be rehomed. To date, around 2,000 corals have been placed at more than 20 facilities in at least 14 states.
“This is the first time an aquatic species has been rescued in this manner,” said Beth Firchau, Florida Reef Tract Rescue Project coordinator.
Unlike other coral diseases, which typically affect about 2 to 3 percent of corals on a reef and fluctuate seasonally, stony coral tissue loss targets more than 20 species and kills its host within a few months — sometimes even weeks.
No one knows what causes the waterborne disease or what sparked its initial outbreak. Climate change, however, has made such events increasingly common.
“Anytime you’ve got warm temperatures and increases in nutrients, it kind of creates this environment that can breed bacteria and increase things like viruses in the water,” said Schopmeyer.
Recently, the U.S. Geological Survey’s National Wildlife Health Center released data suggesting a virus is probably triggering the disease, according to Maurizio Martinelli, Florida Sea Grant’s coral disease response coordinator. A bacterial infection may also be involved. But without knowing for sure, little can be done to stop it.
Since it was first detected near a Port of Miami dredging project, the disease has continued to spread north and south along Florida’s 360-mile-long reef tract, which is valued at $8.5 million for the jobs it creates and the income it brings in from tourism. Corals in more than 17 countries and territories throughout the Caribbean are now being impacted.
“To have something like this last this long and affect this number of species has really never been seen before,” said Jennifer Moore, Threatened Coral Recovery Coordinator for the National Marine Fisheries Service.
No one institution was equipped to manage such a crisis. In 2018, NOAA and the Florida Fish and Wildlife Conservation Commission created the Florida Coral Rescue Team, which would oversee all efforts to collect vulnerable corals, hold them for safekeeping and breed them so that one day their offspring might restore the reef.
The team then sent a plea for additional help to the Association of Zoos and Aquariums. Thousands of soon-to-be-rescued corals needed homes and expert caretakers.
“It is recognized that AZA is the only entity that has the suite of expertise, resources and professionalism to take on this significant conservation challenge,” Florida Fish and Wildlife Research Institute Director Gil McRae wrote in a formal request for assistance.
“The stark reality is that if the Rescue Team cannot fully develop and execute the Rescue Plan within a very short time frame, one third of the coral species that are found in Florida will become ecologically extinct,” he continued.
But there was no blueprint for how to get this done, said Firchau. Few corals from Florida have been held in captivity since the state prohibited the collection of them as a strategic conservation measure in 1976. Most corals seen at aquariums are Indo-Pacific corals. The association began surveying its member facilities across the country, gauging their interest and capacity for joining this rescue mission. Everyone was on board.
The unanimous response, Firchau said, was “What do you need?”
Pulling from their existing conservation budgets and back aisles of surplus equipment, zoos and aquariums began volunteering anything they could — staff time, unused tanks, hallway space, closets and basements. The urgency of the matter was clear, said Stevens, aquatics manager at the Butterfly Pavilion. “We need to basically be triaging these corals out of the ocean,” she remembers thinking upon first learning about the rescue effort.
Over the next few months, facilities in Iowa, Nebraska, Michigan, Ohio, Texas, Tennessee and more scrambled to prepare aquariums with live rock sent from Florida, along with algae-eating critters like snails, hermit crabs and peppermint shrimp.
Meanwhile, small groups of scuba divers embarked on day-long rescue missions throughout the lower Florida Keys, at the time deemed a “preinvasion zone” — meaning the disease had not yet reached the area. Their goal was to collect 200 of the healthiest coral colonies they could find for each of the 19 most disease-susceptible species, for future propagation purposes.
Equipped with two-pound sledge hammers and chisels, the rescue divers searched for stony corals — including brain corals, pillar, star and starlet corals — usually between 30 and 60 feet below the water’s surface. They had to be of reproductive size, have good coloration and show no signs of stress, damage or predation.
“We wanted these corals to have the best chance that they were going to have for kind of being the next generation of corals for Florida,” said Schopmeyer, who was part of the rescue team.
Once located, they methodically photographed each coral in its original location before using their hand tools to carefully chip away at its base on the reef until it eventually popped off. Then they placed it in a zip-top bag with an identification tag before swimming it back to the boat where it was stored on board in a temporary holding tank until it could be transferred to a land-based facility.
As the disease boundary continued to expand further down the Florida Keys, the pressure mounted to collect more corals faster. Larger teams of rescue divers were sent out on a live-aboard cruise vessel named the M/V Makai to conduct seven multi-day rescue missions in the Marquesas Keys and in Dry Tortugas National Park.
By spring 2019, the first rescued corals to leave Florida arrived at the National Mississippi River Museum & Aquarium in Dubuque, Iowa.
The landlocked museum, whose primary exhibits focus on local wetlands, waterways and wildlife, had never cared for the animals before. But it had an aquarist able to learn how, along with an empty basement room big enough to hold two tanks and 25 rescued corals. While the museum’s coral rescue lab is off limits to the general public, small behind-the-scenes tours are arranged upon request. For many of the visitors, Aquarist Amanda Erlandson-Lee says, it’s the first time they’ve seen corals in person — or realized they are in fact animals.
“They think of them as pretty rocks or plants,” says Stevens, the aquarist at the Butterfly Pavilion in Colorado.
Stevens has been tending to 19 rescued corals since February 2020 — just about a month before the zoo closed its doors to the public as a result of coronavirus. She spent months of the nationwide closures giving “TLC” to the new arrivals, she said. Some had been damaged in transit. Some bleached in their new home. Others showed signs of tissue sloughing off, an ominous indication of the disease they were being rescued from.
She tended to each coral, submerging ailing ones in baths of iodine or other antibiotic treatments that have proved effective in stopping the disease spread. Using a toothbrush, she scraped away algae and other pests from each colony. She experimented with placing them in different positions in her 300-gallon stair-stepped aquarium. And sometimes she had to break up fights between corals trying to bully others, using their tentacles to claim more space.
“Real estate is a hot commodity on a reef,” she said.
Gradually, she began to see the corals plump up from all her feeding, their natural green and purple colors becoming more vibrant. But keeping them that way still requires much of her attention. She checks on them several times a day, testing the water quality and looking for any indication one might need extra food.
“There’s a lot of nuances to their care. They can really tell you if they’re happy or not,” she said. And the pressure to help them thrive is great. “We are protecting a national treasure.”
The disease is now assumed to be endemic throughout Florida’s waters. The rescue team is now preparing to launch the next phase of its restoration effort: propagation. Researchers are studying the genetic makeup of all of the rescued corals to determine how to breed them to optimize genetic diversity of any offspring produced.
They’re also collecting and studying corals that have survived in the wild. “There’s a reason that these corals made it through the disease event,” says Martinelli from Florida Sea Grant. Their genetics could be key to creating a new generation of resilient corals that will one day help restore the Florida Reef Tract.
“They really are going to be the parents and the grandparents and then great-grandparents of the corals we’re putting back out onto the reef.”