TCRF Reports Successful Trial in Treating Stony Coral Tissue Loss Disease

#TurksandCaicos, April 8, 2021 – Stony Coral Tissue Loss Disease (SCTLD) is a highly deadly, fast moving disease that affects approximately 30 species of hard corals on the reefs of the TCI.  First observed on the reefs of South Caicos and West Caicos in early 2019, the disease spread quickly to reefs off NW Point, Grace Bay and continues to spread eastward past Pine Cay recently being observed on the reefs off North, Middle and East Caicos.

Scientists in Florida have been dealing with this disease since 2014 and through extensive research identified the antibiotic, amoxicillin, mixed with a specially developed, proprietary ointment base was the most effective option for stopping the progression of this disease.  The antibiotic paste is pressed into the coral tissue at the edge of a disease lesion.  The ointment base expands in sea water to fill the ridges and valleys of the coral skeleton slowly releasing the antibiotic into the coral tissue and minimizing the amount of antibiotic leaching into sea water. 

This is an incredibly labour-intensive, time-consuming and expensive way to deal with the disease but with Florida still seeing infection spread 7 years later, doing nothing is not an option. This disease has the power to severely reduce the populations of live stony coral cover. A recent paper from the School for Field Studies on South Caicos reports an approximate 60% reduction in live coral coverage since the disease outbreak in early 2019[1]. In 2020 TCRF were granted a permit by the TCI Government to test this treatment to determine its effectiveness on TCI reefs and to watch for any untoward effects on the marine environment.  TCRF began trials of the antibiotic treatment and recently completed and filed its final report of those treatment trials with DECR.

The treatment trials were conducted at six locations around the TCI – 3 on the reefs of Providenciales, 2 on those of Grand Turk and 1 on the reefs of Salt Cay. With up to 8 months of monitoring on 122 assessed colonies we are seeing a 93% success rate. Most of the control colonies that were not treated died within a few days or weeks, some of them continue to display slow disease progression. Species specific efficacy ranged from 50% to 100% with most species seeing 67%++ efficacy. To this date no untoward effects have been observed – fish would occasionally nibble on the ointment during treatment, but seemed to ignore it after the first nibble. There are more studies on this happening regionally and TCRF hope to help the studies in any capacity that we can.

“We are very excited to see such a high efficacy rate for our treatment program,” said Alizée Zimmermann, Executive Director of the TCRF.  “Our results are consistent to slightly better than seen in other parts of the Caribbean where this treatment is being used.  It is now considered to be the standard of care for treating SCTLD by the scientists studying the disease.”

These results are very encouraging and the Department of Environment and Coastal Resources has recently granted TCRF a research permit to expand the treatment effort.  The treatment effort with the antibiotic ointment will continue and will target large colonies.  They will be tagged with special tags instructing any divers observing these colonies to take photos of the colony and send them to TCRF at SCTLD@tcreef.org.  This will assist in our ongoing monitoring effort of the treatment program. The goal with the expanded treatment effort is to target and save old, reproductive colonies of the most susceptible species so as to preserve the reef’s genetic diversity and ability to repopulate.

In addition, TCRF is teaming up with Ocean Alchemists, the company that developed the special ointment base for the amoxicillin, to test a new, non-antibiotic treatment.  This treatment option utilizes a proprietary formulation of naturally occurring products and it is impregnated into hemp rope which is then applied around the edge of a lesion.  TCRF will be comparing the effectiveness of this new treatment option to the current standard of care, the amoxicillin ointment.  Testing of the new treatment should begin within the next month.

“None of us want to use antibiotics in the marine environment, but the alternative would result in the loss of many decades to hundreds of years old coral colonies on the reefs that protect our islands from storm surge and wave action,” said Mrs. Zimmermann. “So we are excited to be involved in conducting research on potential alternative therapies that don’t involve antibiotics.”

About TCRF

Founded in 2010, the Turks & Caicos Reef Fund is the only active environmental advocacy organization in the TCI. It is an organization that provides funding for education, research and conservation programs to individuals, organizations and agencies that help to preserve and protect the environment of the Turks & Caicos Islands. Our goal is to have at least 85% of all funds raised through voluntary contributions from divers and snorkelers visiting the Turks & Caicos Islands directed to the Fund’s programs.

Anyone wishing to donate or assist the TCRF in any way can contact them through their website, www.TCReef.org. Scuba divers visiting the islands are encouraged to make a $10 donation through the purchase of a dive tag that can be attached to their dive gear to show their support. Snorkelers visiting the islands can show their support through the $5 purchase of a pink or blue silicone wristband. Visitors can also support TCRF by purchasing a $40 spf50 rash guard designed each year by a different local artist. A complete list of outlets for TCRF merchandise can be found on the organization’s website.