The Disease Threatening Coral Reefs In Martin County


Just off our shores, not much more than a good swim from the sand, you could, until recently, find the most majestic of creatures, on land or at sea. Scientists named it orbicella faveolata. But a dive boat captain would tell you to look for the mountainous star coral, a name befitting its stature.

It began its life in 1694, one year before the Spanish built the Castillo de San Marcos fort in St. Augustine. For 323 years it grew slowly into a formation of coral the size of a Volkswagen, covered in small ridges and peaks, the color of rich mustard and pockmarked with little holes where it takes in life.

“It was pretty spectacular and impossible to replace,” says Martin County Commissioner Doug Smith. “We’re talking about a coral, a living creature, that was more than 300 years old. That’s extremely unique.”

Scientists first noticed a lesion on it in October two years ago. They hoped they could cut the infection off, like amputating a gangrenous limb to save a soldier. By the time they went back for another inspection two months later, the entire thing was infected.
Coral tissue loss disease
Photo courtesy of the Florida Keys National Marine Sanctuary

It died in January 2017.

How we lost this mountainous star coral has stumped scientists. They first discovered a mysterious illness killing coral off the coast of Florida in 2014. Since then, at least a quarter, and maybe as much as two-thirds, of the reef coral from Martin County to Key West has died off.

“The smartest minds in coral around are working on this,” says Kathy Fitzpatrick, coastal engineer for Martin County. She’s part of a taskforce set up to track and try to prevent the disease from spreading. “But yet, we haven’t been able to figure out how to stop it.”

The disease began three years ago during a time when ocean waters over the world warmed, causing coral to die from Australia to the Caribbean. The scientists called it coral bleaching, and when the ocean cooled months later, the disease stopped.

But Florida’s coral continued to die. Scientists figured it was something worse than the bleaching. They called it white plague or white blotch. As it spreads, it leaves the coral looking like ghostly skeletons, devoid of color and turning quickly to crumbly limestone. In Martin County, the northern tip of Florida’s reef, scientists first spotted the white plague in summer 2017, according to the Florida Department of Environmental Protection. At least 50 to 60 percent of the coral in Martin County appears susceptible to the disease, Fitzpatrick says.

The largest known colony of mountainous star coral in southeast Florida dead.
Photo courtesy of Florida Department of Environmental Protection

In response, the state set up an advisory taskforce to study the problem, and Smith was one of the founders. The taskforce went to the Florida Legislature in 2016 to ask for $1 million to study the disease. “We got like a gnat hair away from getting that passed,” Smith recalls.

A year later the committee finally convinced lawmakers to approve the funds, and the state’s budget included it again in 2018. The money in part paid for more than 100 monitoring devices on coral near the inlets along South Florida, Smith says. Mostly, the devices have tracked the deaths of ancient coral. For instance, scientists tracked 65 colonies of rare pillar coral, which look like upturned cucumbers; all but one died.

The loss of coral is far more important than simply an offshore attraction, Smith says. The coral not only serves as a headliner for the $8 billion ocean-related industry in Florida, but it also creates a breeding ground for thousands of species, from tiny microorganisms, to schools of fish, to the predators that circle the reef. Perhaps most important for Florida, the coral also acts as a natural buffer to break up powerful storms before they carry waves ashore. Without the coral, South Florida could be more susceptible to hurricanes and even just regular ocean currents, causing more flooding and erosion.

The mountainous star coral when it was alive.
Photo courtesy of Dr. Dave Gilliam Nova Southeastern University

At first it seemed like the disease affected only limited types of coral, and so scientists hoped it would be contained to just a couple species. Since then, the disease has affected at least 20 types of coral. By the time the disease is done ravaging the coast, nearly all of Florida’s coral might be lost.

It might seem easy to blame the disease on things that can negatively impact coral, including sunscreen, global warming, beach renourishment projects, Lake Okeechobee water discharges and sewage that’s pumped straight out to sea in South Florida. But Fitzpatrick says there’s no proof that any one of those things is the culprit. Instead, they likely combined to make the reef more susceptible to disease.

“It’s like having a cold or getting rundown from being overworked and stressed out and not eating well. It makes you more susceptible to colds,” Fitzpatrick says. “Once you have the corals in such a frail condition, they become more susceptible to whatever it is affecting them.”

Tissue loss on this large colony of great star coral is nearly total.
Photo courtesy of Florida Department of Environmental Protection

It’s possible the disease was something that’s always been here, just not able to spread until the coral became weakened. Or perhaps a ship heading into one of South Florida’s ports illegally dumped its ballast water at sea, releasing a disease imported from some faraway reef. Or maybe it was a microorganism that traveled on the flippers of scuba gear someone used on an infected reef elsewhere, unknowingly carrying it to Florida’s shores.

What scientists have been able to determine is that it’s likely bacterial, says Valerie Paul, head scientist with the Smithsonian Marine Station in Fort Pierce. They figure that’s true because treating the coral with antibiotics seems to help stop the spread of the disease, she says. The problem is that the logistics and cost of treating hundreds of miles of coral with antibiotics make that solution unlikely to stop the spread.

A close-up of an active disease lesion

Early last year, the Smithsonian lab began dropping infected pieces of coral into five-liter tanks. Then they would add coral bought from aquarium supply companies. Paul’s team learned that it takes the disease four to five days to spread when the coral is touching. It can also spread simply in the sea water, although that takes longer.

In July of last year, Paul’s team also began tagging coral, 20 in total, to track their progress. Since then, three have died.

“We still don’t know the organism that’s causing the problem, but luckily we do know some treatments,” Paul says.

Nova Southeastern University researchers have had success using a technique. They’ve been acting like fire jumpers who parachute into wildfires and dig trenches to create firebreaks that the blaze can’t cross. Similarly, the NSU team bores a channel into affected coral, separating a good side from the bad, filling the gap with chlorine powder. The powder kills the coral, giving the disease nowhere to spread. The disease, however, can also spread through the water, so scientists use this method knowing there’s a chance the firebreak method will still not save the coral.

A close-up of healthy tissue and polyps

With the disease spreading so fast and remedies limited, scientists have begun planning for catastrophe. At the Keys Marine Lab, deputy director Cindy Lewis has filled her lab with 230-gallon fiberglass tanks that look like giant feeding troughs. Inside are 200 samples of coral about the size of a dinner plate. Twice a week, Lewis’ team feeds the coral brined shrimp and vitamins. “Coral is a living, breathing animal, so we have to feed them and make sure they have oxygen and all the things they need to survive,” Lewis says.

The samples will eventually, hopefully, represent every species of Florida coral. If all our coral dies, scientists may be able to use this coral bank to repopulate the reef. For now, the lab is the coral’s temporary home, but eventually scientists hope to create a permanent home where they can store the coral, perhaps for years, Lewis says. Maybe then, disease will have wiped out all the coral and then the disease itself will die. Perhaps over the course of decades or centuries, scientists can regrow the coral from the samples saved.

Close-up of diseased polyps
Courtesy of Valerie Paul, head scientist with the Smithsonian Marine Station in Fort Pierce

For Smith, the Martin County commissioner, the hope is that a solution can be found before that happens. He knows, though, that far more resources and attention need to be directed toward a solution.

“It’s awful out there right now,” Smith says. “Time is of the essence, and if we don’t do things with a sense of urgency, it will be catastrophic.”

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