I recently published a story about coral disease in Yale Environment 360, and I’ve had a lot of follow-up through social media. One of the top questions/comments I’ve received concerns Killer Pillar, a Grand Cayman dive site mentioned in the article. I wanted to take a moment here and give folks a little more detail based on my discussion with Tammi Warrender, the individual I mentioned in the story who reported the disease at Killer Pillar to Dr. William Precht.
Killer Pillar is a popular dive site located in the Seven Mile Beach Marine Park on the west coast of Grand Cayman. According to Warrender, who is a visiting scientist and has been diving with the Department of Environment (DOE) in the Cayman Islands since 2013, it the busiest area for dive tourism in Grand Cayman. It is also, she told me, the only known site on the west coast of Grand Cayman where pillar coral (Dendrogyra cylindrus) can be found.
For those of you who have never seen a pillar coral colony, it is truly a spectacular thing to behold. Rising up in majestic, cylindrical columns from the bottom, the namesake pillars can reach two to three meters in height, dwarfing the surrounding coralscape. Grey-brown in color, filtered sunlight paints the pillars a golden hue, accentuating the animal’s uncharacteristic hair-like texture. These “hairs” are actually the individual coral polyps feeding, an unusual sight for many divers, as most corals feed largely at night.
While never the dominant species in the western Atlantic, pillar corals find themselves in an ever more precarious situation. Now listed as “threatened” under the Endangered Species Act, pillar corals became a focus of scientists responding to the 2014 disease outbreak in Florida. A monitoring program that stretched along the Florida Reef Tract from central Miami-Dade County to southern Palm Beach County tracked 65 individual colonies. Despite some efforts to mitigate the ravages of the disease, within three years, all but one of those 65 colonies had turned from a vibrant focal point of reef life to a ghost white skeleton soon overgrown with algae. Today, it’s estimated that 96 to 99 percent of Florida’s pillar corals have been lost to disease earning the few surviving colonies the epitaph “the last unicorns.”
Within this context, the discovery of disease at the Killer Pillar dive site off Grand Cayman in June of 2018 raised serious alarm bells for Warrender. She says she’s always observed some degree of coral disease on Cayman Island reefs since she started diving with DOE some eight years ago, but now she’s seeing more. “Unfortunately, this is the common trend around the world, and coral disease outbreaks are becoming more frequent, severe, and widespread.”
The disease at Killer Pillar was reported to DOE by a local dive company called Cayman Ecodivers. “The disease outbreak at Killer Pillar was already well underway,” Warrender recalls, “and several colonies were highly infected by the disease.” Given that other pillar coral colonies in the Cayman Islands were also showing signs of disease, she was thinking worst case scenario: local extinction.
Warrender led the disease intervention effort, working with individuals from the DOE Research Unit, Operations Unit, and other external associates such as Precht, Cayman Ecodivers and Dr. Karen Neely (who was also featured in the Yale E360 story). “It was a challenging project using several intervention methods, some of which have never been tried before on this specific species,” says Warrender. “I was very driven to carry out this research, knowing that if we did not intervene, it is highly likely that entire pillar colonies, hundreds of years old, would die.”
As I described in the Yale E360 article, Warrender and her team salvaged healthy parts of colonies by sawing them off and transplanting them on other reefs. They used chlorinated epoxy to try to stop the spread of the disease, and they treated healthy tissue fragments with a povidone iodine and seawater solution before moving them to a nursery in hopes of preserving them.
“So far some of our methods have been successful,” she says, “but only time will tell whether our treatments and the pillar coral colonies at Killer Pillar will survive this outbreak.” She says research officers at DOE are continuing to monitor the results of the experiments. Recently Warrender et al. published preliminary results of the experiment at a poster session presented at Reef Futures 2018 (see below).
“The best thing about this experience was working together with other coral disease researchers to figure out solutions to save this charismatic and rare species,” Warrender says. “This research gives hope that we can assist the survival of corals, which are highly infected by disease, however, our interventions are only buying time for the corals–we are treating the symptoms, not the underlying cause. These interventions should be used only in conjunction with large scale efforts to minimize our environmental impact and reducing carbon emissions.”
The effort to save Killer Pillar, like the effort Neely discusses in the Yale E360 article to save the last remaining high-density stand of pillar coral in the Florida Keys, may seem futile to some. In fact, I received a lot of feedback from readers of the article who expressed concern about overly-hyped optimism in the media regarding these types of interventions. Critical readers worried these interventions are experimental, expensive and not scalable. In many ways, I agree with those criticisms, but I think we must talk about context. If the goal is “Save the Reefs,” then I think we need to be having a very different conversation than the one which continually (and optimistically) profiles high-tech, experimental interventions. But if we’re talking about saving a reef or a legacy coral colony then these interventions–the efforts by scientists like Wallender–should be front-and-center.
The oceans are warming and annual severe bleaching events may increasingly occur. Coral diseases are reported with more frequency and over a broader area, and, in places like Florida, the anthropogenic stressors are not going away anytime soon. We likely can’t save the reefs–we likely can’t even return them to a severely shifted baseline–but perhaps we can create “systems in waiting.” These systems in waiting, beyond the importance of being a genetic repository of biodiversity, may be the tools that help inspire future generations to develop the political will and scientific interventions to return the oceans to a state where coral reefs will once again thrive.
To learn about scientists working to save the last remaining high-density stand of pillar coral on the Florida Reef Tract, read my full article “As Disease Ravages Coral Reefs, Scientists Scramble for Solutions” in Yale E360. You can follow Tammi Warrender on Instagram at @coralreefwarrior.