To protect Gulf coral, disinfect before diving

Officials seek to prevent the spread of mysterious disease damaging reefs

The dead husks of coral colonies first were spotted off the coast of Miami, Fla., in 2014. Their once-vibrant hues now the brownish color characteristic of dead leaves.

At first, researchers weren’t sure what they were seeing. But then, the disease began racing up and down the coastline with unprecedented speed, leaving millions of dead coral colonies in its wake.

It’s been four years, but scientists still don’t know what caused the disease or how to stop it. Concerned that it might be contagious, Texas officials now are asking divers to disinfect before splashing into the Gulf of Mexico, where 56 square miles of coral are federally protected from overfishing and harassment but not from a disease with no name or known origin.

“There’s a high concern that it could be transmitted by divers on their equipment,” said G.P. Schmahl, superintendent of the Flower Garden Banks National Marine Sanctuary located about 100 miles off the coast of Galveston.

Though there haven’t been any traces of the dis-

“There’s a high concern it could be transmitted by divers on their equipment.” G.P. Schmahl, Flower Garden Banks National Marine Sanctuary

ease spotted in the sanctuary, its protectors are desperate to keep it that way: At a time when a quarter of coral reefs worldwide are considered damaged beyond repair, the sanctuary’s three reef systems are, mostly, in good shape.

Devastating disease

It’s not exactly unusual to find dead corals off the coast of Florida: Severe bleaching events have left the Florida Keys Reef Tract with less than 10 percent living coral along the sandy, shallow bottom.

But researchers soon realized this time was different — and they’ve spent the last four years trying to bring their knowledge up to a speed that matches the disease’s rate of travel.

They haven’t been successful thus far.

“It’s a mystery,” said Abigail Clark, who recently was hired to study the disease at the Elizabeth Moore International Center for Coral Reef Research & Restoration in Summerland Key, Fla. “We don’t know what caused it, why it’s spreading so fast or why it’s affecting so many species.”

In 2015, just a year after the disease first was discovered, it had attacked 55 linear miles of reef. It continued to spread from there. As of this year, the Florida

Department of Environmental Protection estimates the disease has spread 205 linear miles up and down the Florida Keys.

And it’s killing almost everything it touches.

For the foreseeable future, Clark will be working to identify the pathogen responsible for the disease, using diseased coral tissue samples and water samples to pinpoint the cause or, at the very least, find species that are resistant to it.

The Moore center’s claim to fame is their coral restoration work, in which they grow new coral in a lab from harvested fragments and plant them on the depleted Florida Keys reef. They’ve planted more than 35,000 coral thus far.

If Clark can find species of coral resistant to the disease, scientists can focus more on planting those species on the reef and, potentially, breeding those species with others for a more resilient hybrid.

But that work still is a while away. Scientists still are trying to figure out what type of disease it is: they think it’s bacterial, she said, but they’re not even 100 percent sure about that.

“We really don’t know much,” she added.

They do know, however, that it appears to only impact large boulder coral, which typically line the bottom of reefs and act as building blocks for the whole ecosystem. Researchers

have tried to infect branching coral — which, as their name suggests, have many branchlike offshoots from their base — without success, she said.

“That’s a minor triumph,” Clark said. “It won’t get every coral colony, which is good.”

But so far, it appears that 20 different species can and are contracting the disease — many of which are also found in the Flower Garden Banks.

Potential source

The about 3,000 divers that visit the Gulf of Mexico’s sanctuary each year is an exciting number in economic terms but terrifying if the coral disease turns out to be contagious.

That’s because the dive to Flower Gardens is not for

the inexperienced. At 70 to 115 miles off shore and 55 to 160 feet deep, divers need to know what they’re doing and likely have done dives across the globe with their own diving equipment.

So, sanctuary officials are working with Fling Charters, the only recreational dive boat that travels specifically to Flower Gardens, to ensure that each divers’ equipment is disinfected before they enter the Gulf, Schmahl said.

Sanctuary officials provided the dive company disinfectant six weeks ago, and Sharon Cain, the company’s office manager, said they’ve been asking customers to dip their gear in the solution.

But they can’t force them to do it until an official edict comes down from the National Oceanic and Atmospheric

Administration’s National Marine Sanctuary Office, she said.

“If they don’t want to do it, we have no recourse to make them do it,” she added.

Responses to the request have been mixed. Some people have no problem sanitizing to help protect the reef, Cain said, but others are leery that the solution might harm their gear.

But they have to try to keep the coral disease out of the Gulf, Schmahl said.

“When it gets established on coral, over the course of a year or two, there is complete mortality,” he said. “The least we can do is enhance awareness about it and try to prevent it from spreading.”