Coral Disease Outbreak

Stony coral tissue loss disease

Stony coral tissue loss disease (SCTLD) is a new lethal disease first reported in Florida in 2014. The cause of the disease is unknown but it is affecting >30 species of corals especially brain, pillar, star and starlet corals. The disease spreads quickly causing high coral mortality. Since then, outbreaks of SCTLD have been confirmed in 28 countries/territories throughout the Caribbean off Antigua and Barbuda, Aruba, Barbados, Belize, Bonaire, British Virgin Islands, Cayman Islands, Colombia, Curaçao, Dominica, Dominican Republic, Florida, Grenada, Guadeloupe, Honduras, Jamaica, Martinique, Mexico, Puerto Rico, Saba, Saint Barthélemy, Saint-Martin, Sint Eustatius, Sint Maarten, St. Kitts & Nevis, St. Lucia, St. Vincent & the Grenadines, The Bahamas, Turks and Caicos Islands, and U.S. Virgin Islands. For full up to date information, see the Caribbean SCTLD Dashboard discussed below.

Characteristic of this disease is that sick colonies display multiple lesions and quickly die. Highly susceptible species are the meandroid corals–i.e., pillar corals (Dendrogyra cylindrus), elliptical star corals (Dichocoenia stokesii), smooth flower corals (Eusmilia fastigiata) and maze corals (Meandrina spp.). 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 (Orbicella spp., Montastraea cavernosa) and other coral species.

Tracking the Disease

Map of Stony Coral Tissue Loss Disease recorded throughout the Caribbean – The SCTLD Tracking Map is an interactive map that shows where SCTLD has been confirmed in the Caribbean. Sightings are submitted through the Online SCTLD Survey Form which then appears on the map as purple markers while the information is being thoroughly reviewed. Once reviewed, the markers turn green if SCTLD is not present/confirmed or Red if presence of SCTLD is confirmed. As SCTLD, bleaching, and other disease and mortality data are collect in these forms, please be aware that photos attached and displayed in the map below may include instances of any one or more of these conditions. Florida data is provided by FWC’s Florida Fish & Wildlife Research Institute.

To submit a sighting or survey in the Caribbean, please see the “Report Sightings of SCTLD” section of this page or contact us at

Mapa – Enfermedad de pérdida de tejido en corales durosversión en español

If your browser fails to download this map, we suggest you try another browser. For Mac users: use latest Safari; Firefox or Chrome.

To cite or use this map in a report or publication: Kramer, P.R., Roth, L., and Lang, J. 2019. Map of Stony Coral Tissue Loss Disease Outbreak in the Caribbean. ArcGIS Online. [access date]. Check back frequently for updates.

(From Kramer et al 2022, FIELD GUIDE for Monitoring Coral Disease Outbreaks in the Mesoamerican Region).  FIGURE 6. Location of countries/territories where SCTLD has been confirmed in Wider Caribbean Region as of July 2022. (Map designed by AGRRA). For recent updates, see the AGRRA SCTLD Tracking Map.


Report Sightings of SCTLD

Reef researchers, managers and sport divers should continue to be on the lookout for sites with an unusually high percentage of diseased and very recently dead corals. If you see see any instances of disease, please submit your findings via the survey form below. Thanks to everyone who has responded so far.


We have improved and simplified the survey forms into a Basic and Detailed form (see below for descriptions). New to the form is the ability to add data on Coral Bleaching. The main difference between the two forms is the Basic form is simple and includes estimates of corals affected, versus the detailed form allows actual coral colony counts and more site information. 

All data are still shown on the SCTLD Tracking map above and the new coral bleach map (  All information collected from previous surveys is still available in the map. Check out the videos for how to use the new forms. Any questions, please contact us at Thank you for contributing to this collaborative effort to monitor and protect Caribbean coral reefs.

This simple survey form allows you to enter presence/absence data on corals affected by SCTLD and bleaching by coral species and estimates of corals affected, photos and site information. You can identify survey method used such as rover diver, bar drop, general observation etc.

NEW combined SCTLD / coral bleaching survey data sheet can be used for basic or detailed surveys. This corresponds to the online data entry tool and tracking map. Click here or image below to access.

This detailed survey form allows you to input more detailed quantitative data on the number of coral colonies affected by stony coral tissue loss disease and/or coral bleaching (fully bleached, partly bleached, pale), recent coral mortality, photos and site information. You can identify the method used such as rover diver, bar drop, etc.

Watch this Video tutorial on the new Detailed Survey form. Click on image below.

If you have any questions related to diseased coral outbreaks please contact

Caribbean SCTLD Dashboard

The Caribbean SCTLD Dashboard below provides summary information on the outbreak of SCTLD in the Caribbean and the regional efforts to respond to the disease. At the MPAConnect regional peer-to-peer learning exchange on SCTLD held in August 2019, Caribbean coral reef managers recommended the development of a regional dashboard to indicate the status of SCTLD and show the spread of the disease in the Caribbean. This dashboard is a direct response to that request. The dashboard was developed by AGRRA, in collaboration with MPAConnect, GCFI, and NOAA and is updated biweekly to monthly.

Dashboard features include statistics on countries affected and management response activities.

Upper Right Map shows:

– Presence/absence of SCTLD

– Response activities (training, education, monitoring, treatment)

Bottom Left Map shows a time-lapse of how SCTLD has been reported to occur through the region.

Lower Right Graph shows the coral species affected by SCTLD by number of countries reporting diseased corals.

To cite or use this dashboard in a report or publication: Roth, L., Kramer, P.R., Doyle, E., and O’Sullivan, C. 2020. Caribbean SCTLD Dashboard. ArcGIS Online. [access date]. Check back frequently for updates to the dashboard.

How do I identify it?

Click on the image to the right to view the presentation from Andy Bruckner, NOAA, September 2020, “How do you recognize and describe Stony Coral Tissue Loss Disease (SCTLD) lesions?”

How is this disease different?

While disease outbreaks are not uncommon, the Stony Coral Tissue Loss Disease Outbreak event has never previously been recorded. See Case definition (Oct 2, 2018).

This is how the disease was characterized in Florida in 2018.

Key factors of the SCTLD outbreak are*:

  •  Many coral species affected -Unlike other coral diseases, SCTLD has affected >20 species of approximately 45 Caribbean reef-building coral species. Certain species are highly susceptible to SCTLD. Other species, like acroporids, have not been affected.
  •  High prevalence – SCTLD disease is seen in many to all colonies of highly susceptible species. In Florida, 66-100 out of every 100 colonies surveyed were infected.
  •  Rapid mortality – Once a coral is infected, it begins to rapidly lose living tissue and the colony dies within weeks to months.
  • High rates of disease transmission –When SCTLD is present on a reef, it spreads rapidly. Recent studies have suggested the disease is caused by a bacterial pathogen which can be transmitted via direct contact or through the water column.
  • Large geographic range – SCTLD outbreaks occur over large spatial scales. Over half of the Florida Reef Tract has been affected: > 96,000 acres since 2014. SCTLD is now found along the entire Mexican Caribbean coast and has affected >30% of all corals.
  • Long duration of the outbreak. SCTLD has continued to spread for more than four years in Florida.

*Information adapted from the Florida Disease Advisory Committee and Florida Department of Environmental Protection

Which Corals Are Affected?

Highly Susceptible Species*: Early onset (the species first affected during an outbreak), with rapid progression, and total mortality ranging from one week for smaller colonies to complete mortality over 1-2 months for larger colonies. Typically, M. meandrites and D. stokesii are the first to become affected at a site, followed by C. natans, and then the others show disease signs shortly thereafter.

Intermediately and Low Susceptible Species: a comprehensive list of other species that are less susceptible are found on the Coral Disease Identification Page. *Information adapted from the Florida Disease Advisory Committee and Florida Department of Environmental Protection

Colpophyllia natans (CNAT or boulder brain coral)

Dendrogyra cylindrus (DCYL or pillar coral)

Dichocoenia stokesii (DSTO or elliptical star coral)

Diploria labyrinthiformis (DLAB or grooved brain coral)

Eusmilia fastigiata (EFAS or smooth flower coral)

Meandrina meandrites (MMEA or maze coral)

Pseudodiploria strigosa (PSTR or symmetrical brain coral)

Pseudodiploria clivosa (PCLI or knobby brain coral)

What Does it Look Like in Florida?

Click on the image to the right to see how to identify the appearance of Stony Coral Tissue Loss Disease (SCTLD) on susceptible corals in Florida. Presentation provided by Karen Neely.

To view/download the complete presentation PDF, click here.

Susceptible Coral Species

Many different coral species are susceptible to the stony coral tissue loss disease. This interactive map allows the user to view the coral cover (recorded in AGRRA benthic surveys) of these susceptible species in different groupings/layers including:

  • Percent Coral Cover of 20 susceptible spp
  • ORBI spp: Orbicella species
  • 8 SCTLD spp: 8 of the most common SCTLD susceptible species (Colpophyllia natans, Dendrogyra cylindrus, Dichocoenia stokesii, Diploria labyrinthiformis, Eusmilia fastigiata, Meandrina meandrites, Pseudodiploria clivosa, Pseudodiploria strigosa)
  • AGAR spp: Agaricia species
  • SSID: Siderastrea siderea
  • DCYL: Dendrogyra cylindrus

Mapa de especies susceptibles versión en español

To cite or use this map in a report or publication: Kramer, P.R., Roth, L., and Lang, J. 2020. Map of Coral Cover of Susceptible Coral Species to SCTLD. ArcGIS Online. [access date]. Check back frequently for updates.


Actions to monitor and prevent the spread of the disease.


See Field Guides, Training Materials, Infographics, Action plans and more.


View SCTLD webinars, related presentations and videos.