Probiotic Breakthrough Slows Coral Disease Spread in Florida Waters

A beneficial probiotic has shown promise in slowing the spread of a deadly coral disease affecting Florida’s reefs, according to new research published in *Frontiers in Marine Science*.

The study, led by scientists at the Smithsonian Marine Station, examined a bacterial strain called MCH1-7, which produces a compound known as tetrabromopyrrole (TPB). Discovered in 2018 on a coral that had naturally resisted stony coral tissue loss disease (SCTLD), the bacteria and its compound are now being tested as a potential treatment.

Researchers applied the probiotic to great star coral (*Montastraea cavernosa*) in two ways: by injecting it into seawater contained in weighted bags around the coral, and by applying a paste directly to disease lesions. The bag method, which treated entire coral colonies, proved far more effective, reducing tissue loss to 7 percent over 2.5 years, compared to 35 percent in untreated corals.

The paste application, however, did not yield similar results, indicating that whole-colony treatment may be necessary for lasting protection.

The study’s authors concluded that while the bag method requires more effort from divers, its effectiveness in slowing disease spread and promoting long-term resistance makes it the preferred approach for probiotic treatment.

Lead author Kelly Pitts emphasized that this is an early step in developing a potential solution. “It’s important to understand that this is the very beginning,” she said in an interview with *Mongabay News*. “This is definitely not a cure-all, but we’re definitely moving in the right direction.”

The research team also confirmed that the probiotic method does not harm other healthy Caribbean coral species, suggesting it could be a viable treatment for full coral colonies affected by SCTLD.

While the findings are encouraging, the authors stressed the need for further research to refine the method and explore additional treatments for other coral species devastated by the disease.

Stony coral tissue loss disease has devastated reefs in Florida and the Caribbean, prompting urgent efforts to find scalable solutions. This study represents a promising advancement in coral conservation, offering a science-based approach to disease mitigation.

Researchers plan to continue testing probiotic applications in real-world conditions, with the goal of developing practical tools for reef restoration.