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Silent Killer: The Deadly Spread of Stony Coral Tissue Loss Disease

Lily Haines
March 31, 2021

We made headlines this month for our ongoing efforts to stop the spread of Stony Coral Tissue Loss Disease (SCTLD). This ‘silent killer’ is a disease that has plagued our country’s popsicle-blue waters for over a year, traveling up to 50 meters (55 yards) per day and killing hundreds of corals in its wake.

“The reality is, the disease is spreading and it’s spreading very fast,” said Dr Valeria Pizarro, our senior coral reef scientist. “If we lose those species which build up coral reefs, we might lose coral reefs in the long term with profound ecological impacts,” she said.

Healthy symmetrical brain coral, *Pseudodiploria strigosa* (left), in waters off New Providence. The same brain coral was affected by Stony Coral Tissue Loss Disease (right) approximately one month later. The white area of the coral is already dead as the disease advances.

PIMS is a key member of the Bahamas Stony Coral Tissue Loss Disease Task Force, and has already confirmed the presence of SCTLD on reefs off Grand Bahama, New Providence and North Eleuthera. Our early assessments also show some species are more susceptible than others; brain corals, for example, are particularly susceptible to infection and often die within weeks.

‍SCTLD has also been reported but not verified in Abaco and the Exumas. Worse still, the disease affects more than 20 hard coral species in the Caribbean.

“I’ve been diving since I was a teenager and I’m now in my 30s, and I’ve never seen so much coral death,” said Dr. Krista Sherman, a fellow senior scientist at PIMS. “It’s depressing.”