1. What is SCTLD?
Stony coral tissue loss disease (SCTLD) is a new disease that was first reported in Florida in 2014. The disease affects more than 30 species of stony corals which are the architects of the reef and provide key habitat to many species.
2. What species of corals are affected?
SCTLD follows a natural progression first affecting highly susceptible corals such as pillar corals, maze corals, elliptical star corals, flower corals, and brain corals in their early stages. Starlet corals that develop numerous “blotchy” lesions, as well as diverse brain and star (boulder) corals, are also dying fairly quickly, followed by star corals and other coral species.
3. Where has the SCTLD outbreak been confirmed?
SCTLD has been reported in 17 countries, along the Caribbean off Jamaica, Mexico, Sint Maarten, the US Virgin Islands, Belize, Sint Eustatius, The Bahamas, Puerto Rico, British Virgin Islands, Cayman Islands, Guadeloupe, St. Lucia, Honduras, and Martinique. Currently, only 11 countries are currently doing intervention and 18 countries are monitoring for SCTLD.
4. When was SCTLD first reported in Honduras?
SCTLD was first confirmed at the end of September in Flowers Bay 2020, thanks to a citizen science report. As of now, it is only present on the island of Roatan.
5. What causes the disease and does it have a cure?
Researchers in Florida have been studying the disease since 2014 and have reported a bacterial component but due to the disease complexity, they still do not know the exact pathogen that causes it. Sadly there is no cure for the disease.
6. How does SCTLD look like and how does it spread?
SCTLD causes multiple lesions which leave a white exposed skeleton and it is characterized by a rapid progression and mortality. Corals can lose up to 4cm2 of live tissue per day. It is water borne and can spread via direct contact, ocean currents and ballast water.
7. What is the progression of the disease in Roatan?
8. What is the RMP currently doing to mitigate this disease?
The RMP in the last six months has invested in monitoring and intervention actions. We are using amoxicillin mixed into a non-soluble marine epoxy called Base2B. Every week the team is actively training volunteers on disease identification and how to apply treatments while expanding our citizen science reports and efforts to engage the public in helping us identify diseased coral. We are engaged in regional and international collaboration, and our team has conducted over 1641 treatments.
9. Why is it important to tag and reassess corals?
SCTLD has no known cure, many corals need more than one application of treatment to stop the disease from progressing which is why we reassess the colonies every month. Tags help us identify and find treated corals, data from each coral will help us understand how each colony reacts to the treatment. The treatment efficacy depends on the species and the site.
10. What are the limitations of the treatment?
Currently, Base2b mixed with amoxicillin is the most effective and widely used treatment for SCTLD. However, it is designed to keep a colony alive and stop the disease at the margin, it cannot keep a coral from getting re-infected. Even our most extensive efforts will not stop the spread of the disease or rid the reef of disease. Additionally, in surging/current conditions the treatment does not adhere well, and we cannot properly treat deeper reefs due to time constraints.
11. What can we expect for the future?
SCTLD will likely remain in our reef for an exceptionally long time, in Florida SCTLD is still causing low levels of new infections in surviving corals. That is why our time and efforts need to be focused on priority corals and resilient colonies. Many of the less susceptible species will likely survive partial mortality from the disease and can be expected to recover on their own.
12. Why is the RMP not treating every colony that has SCTLD?
Unfortunately, we do not have the time or resources to treat every coral colony. We are currently focusing on “priority corals”, large colonies of highly susceptible corals which are naturally rare in Roatan, and corals that are important for reproduction, reef structure, and have cultural or touristic value.
Prioritizing is the most cost-effective option to tackle this massive challenge. Additionally, small strategic applications greatly reduce the risk of antibiotic resistance in bacteria which could evolve and enter our food chain and minimizes the input of antibiotics into our reef.
13. How can you help?
Currently, our biggest limitation is trained personnel. We have a small passionate team leading these efforts, and we really need more helping hands. Please consider volunteering your time for intervention, reassessment, monitoring, or data input. The more people we have the more priority corals we can treat! Disinfecting your gear, when diving healthy reefs is key to mitigate the spread of the disease.
Only by working together and collaborating can we try to mitigate the effects of SCTLD.
14. How can I disinfect my gear?
Download Divers Guidelines Here
15. Who do I contact for more information?