WMNF reports on a devastating coral disease that started in the Miami area and has spread to nearly all of the Florida reef tract. The infection known as stony coral tissue loss disease can now be found as far away in the Caribbean as Mexico, Jamaica, the Dominican Republic, the U.S. Virgin Islands and St. Maarten. The article gives an overview of WMNF’s previous reports in 2016 and 2018, and an interview with scientist and manager of the Coral Reef Research Program in St. Petersburg, Rob Ruzicka.

[. . .] When WMNF reported on this coral disease outbreak in 2016, it had spread from nearby a dredging project at PortMiami to Martin County in the north and to the northern part of the Florida Keys National Marine Sanctuary in the south. But now it has spread all the way to Key West and beyond.

Our guest on WMNF is a scientist in St. Petersburg, Rob Ruzicka. He is the Coral Reef Research Program manager at the Fish and Wildlife Research Institute (FWRI), which is a branch of the Florida Fish & Wildlife Conservation Commission (FWC).

“We refer to this disease as the stony coral tissue loss disease, as you introduced. And it’s a necrotic condition that some of the laboratory diagnosis shows that it begins from the inside out of the corals. So it actually begins underneath the skeleton, the initial lesions, where they occur, and then it begins to work its way on the outside of the skeleton. And what can happen is when the lesion moves to the outside of the coral, you begin to see either a banding pattern, or a blotchy white pattern, and this will spread across the coral in a relatively quick amount of time. And if that banding pattern progresses across the coral colony, it actually kills the living tissue as it moves across. And the tissue begins to either slough off — or come off the coral — as it’s being killed by the coral. So what will happen, is you will then see the white bare skeleton that is left behind, that won’t actually have any of the living tissue of the coral left.”

When the coral dies from this disease, what does that do to the reef?

“Well, the problem with it is, in terms of the stony coral tissue loss disease event — just taking one step back in the bigger picture. Coral epidemics and coral diseases have occurred before. We’ve been seeing them occur since the 1980s, and we have seen Caribbean-wide disease events happen. But in the past, they’ve generally targeted one or two species of coral at that time. And the disease event or the epidemic occurs maybe for several months or a year. What’s been different about the stony coral tissue loss disease event is we’ve observed lesions on more than 20 different species of coral. So that’s nearly half of the coral species that actually live on the Florida Reef Tract, and that’s what’s so devastating about this. Now, within those 20 species of coral that are affected by this, many of them are the primary architects and principal reef builders that have created our reefs over thousands of years. And, so, when these corals get these lesions, and the entire colony is actually killed or destroyed, we’re going to lose that framework and that habitat that provides homes and places for all the other fishes, many of the other invertebrates that occur on the reef, so we’re going to lose that habitat complexity and those homes for all the other organisms on the reef.”

How and where did this coral disease begin?

“This disease was first observed and documented by colleagues of ours in 2014 in South Florida, specifically in the Miami-Dade and Broward County area where the first corals with lesions that were documented. And then since then it’s persisted. It’s now a five-year event, and it has moved to about 75% of the Florida Reef Tract.

[. . .] Corals in Florida, in general, are in a perpetual state of stress and have been for decades. There was also some extensive coastal construction activities that were going on at that time. The Port of Miami was performing its dredging to deepen its port for Panamax vessels. So there could have been a confluence of stressors that were occurring either because the water quality conditions, coastal construction activities, thermal stress that was occurring in the water. And it could be a confluence of all these different stresses that could have created the start of this event.

“Now where we are five years later is that the disease has spread northward and encompassed all of the northern portion of the Florida Reef Tract going up to Martin County and our most recent observations and reports have found it off of Key West. That’s why I say that it has encompassed about 75% of the Florida Reef Tract at this time.” [. . .]

For full article and radio program, go to https://www.wmnf.org/floridas-devastating-coral-disease-spread-caribbean-scientist/