6 April 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 Middle and North Caicos.
Scientists in Florida have been dealing with this disease since 2014 and through a great deal of 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. Obviously this is a time consuming and expensive way to deal with the disease, but doing nothing would result in severely damaged reefs. For example, the School for Field Studies on South Caicos reports that their reefs have lost approximately 60% of live coral coverage since the disease outbreak in early 2019.
Although there was some resistance from the TCI Government to the use of antibiotics in the marine environment, they agreed that we needed 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 in early 2020 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 – three on Provo reefs, two on Grand Turk’s reef and one on Salt Cay’s reef. The results clearly demonstrated that the treatment was nearly 90% effective in stopping disease progression on infected corals. All the control colonies that were not treated died within a few days or weeks. The treatment was very effective across all coral species treated. No untoward effects were observed – fish would occasionally nibble on the ointment, but seemed to ignore it after the first nibble.
“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.
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.
“No one is crazy about using 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 Ms. 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 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.