News & Blog

A mysterious coral disease is ravaging Caribbean reefs

Story published in ScienceNews by Cassie Martin, July 9, 2019

Off St. Thomas, the disease is moving faster and killing more corals than any disease before.

CORAL KILLER Lesions (white) eat into the tissue of maze corals on Flat Cay reef, near St. Thomas in the U.S. Virgin Islands. The lesions are caused by a new and deadly disease that’s spreading through the Caribbean.

Divers monitoring coral reefs off St. Thomas in the U.S. Virgin Islands in January noticed something alarming: Big white lesions were eating into the colorful tissues of hundreds of stony corals. Some corals were dead by the next day — only their stark white skeletons remained. Others languished for up to two weeks. Within four months, more than half of the reef suffered the same demise.

What’s killing the corals is far from clear, but the prime suspect is stony coral tissue loss disease, sometimes referred to by its initials SCTLD or by the nickname “skittle-D.” This infection, discovered off Florida in 2014, is responsible for what some scientists consider one of the deadliest coral disease outbreaks on record.

Mapping cases of stony coral tissue loss disease
Source: P.R. Kramer, L. Roth and J. Lang/AGRRA 2019 (Data source: AGRRA)

Click to read more of this story.

Update of SCTLD in Southeast Florida

Update of SCTLD In Southeast Florida, May 22, 2019.
Submitted by Brian Walker, Nova Southeastern University, Florida

M. cavernosa with expanding SCTLD lesion that has crossed its firebreak.
Photo by  © Brian Walker 2019

Over the last few weeks in Southeast Florida, we may be seeing the SCTLD disease on Montastraea cavernosa (MCAV) spreading more rapidly than before, and now large Orbicella are getting reinfections and needing more re-treatments. We have many firebreak margins with amoxicillin treatments that have lost a lot of tissue within a week. The good news is the firebreaks are holding at the early (two weeks) stage.

On many of our MCAV, the tissue is sloughing off rapidly without a bleached tissue margin. See attached example in which the disease crossed our firebreak and spread over this coral in about 5 weeks. Also notice several single, new disease spots way ahead of the margin. Anecdotally, the overall disease prevalence in areas our strike teams have been diving (nearshore northern Miami-Dade) is still relatively low.

This seems to be following the same pattern as last year when more treatments were required in May and June, and once again seems to correspond to the onset of the rainy season (we had a very rainy end of April). 

Reef Resilience Network Webinar, May 8 – Stony Coral Tissue Loss Disease: Lessons Learned & Resources from Florida

On May 8 at 11 a.m. EST, Reef Resilience Network is hosting a webinar – Stony Coral Tissue Loss Disease: Lessons Learned & Resources from Florida. Registration is required. 

Florida’s corals reefs have been experiencing devastating effects of a multi-year outbreak of Stony Coral Tissue Loss Disease (SCTLD). This disease has now been observed and reported in several other Caribbean locations. In response, experts from Florida have been compiling their knowledge, resources, and lessons learned to share with others. Join us to hear from Dana Wusinich-Mendez (National Oceanic and Atmospheric Administration), Maurizio Martinelli (Florida Sea Grant), and Dr. Andrew Bruckner (Florida Keys National Marine Sanctuary) as they discuss our current knowledge of SCTLD, Florida’s response to this disease outbreak, the status of SCTLD in the Caribbean, and current resources available on the disease. Presentations will be followed by a Question & Answer session with these experts

Register Here:

As Disease Batters Florida Reefs, Scientists and Community Fight Back

Published in TheScientist, Carolyn Wilke, April 4, 2019

A reef off the coast of Florida that suffers from stony coral tissue loss disease.

Stony coral tissue loss disease has already affected 80 percent of Florida’s coastal reef system. Now, a huge team of responders is working to slow its spread and prepare for future restoration efforts.

A brutal disease is ravaging Florida’s reefs. Stony coral tissue loss disease first cropped up in 2014 in the shallow waters near Miami, before spreading north along the coast as well as south and west into the Keys. Roughly 80 percent of Florida Reef Tract, a system similar to a barrier reef, is now affected. In response, scientists studying the disease are teaming up with institutions and the public in a massive coordinated effort to stem the spread of stony coral tissue loss disease and look ahead to someday restoring the reefs that have already been damaged.

Read more about the various Restoration efforts.

Glimmers of Hope- A collaborative effort is helping the Florida Reef Tract cope with a coral disease outbreak.

Glimmers of Hope

Story published in Alert Diver Online . Written by Andrew Bruckner, Research coordinator for the Florida Keys National Marine Sanctuary.

Through an unprecedented collaborative effort, a dedicated response to stony coral tissue loss disease is underway within the Florida Reef Tract. By advancing understanding of the disease and developing options to manage it, the project offers glimmers of hope for a threatened coral reef ecosystem.

Read the full story here.

First report of Stony Coral Tissue Loss Disease in the Dominican Republic

Authors: Iker Irazabal, Reef Check Dominican Republic and Manuel Alejandro Rodriguez, Maguá Ecological Foundation, Sosúa, Dominican Republic.

This report documents the first known instance of the Stony Coral Tissue Loss Disease (SCTLD) in the north coast of the Dominican Republic. The disease, which currently affects a number of territories in the Caribbean, appears to be spreading and is a cause of concern to the scientific community and area managers across the region. The disease was observed on 3rd March 2019 in and around the reef of Cayo Arena, near the town of Punta Rucia, Puerto Plata. The species infected, and the pattern of infection follows what has been previously reported for the disease.

Read full report here : First report of Stony Coral Tissue Loss Disease in the Dominican Republic

Save the Date – March 11, Mesoamerican Reef Data Explorer Platform Launch

Press Release March 11, 2019

In commemoration of the Mesoamerican Reef Day, the Healthy Reefs for Healthy People Initiative (HRI) is launching the brand-new Mesoamerican Reef Data Explorer Platform in collaboration with Atlantic and Gulf Rapid Reef Assessment (AGRRA) where users will be able to visualize over 10 years of reef health data collected, through interactive maps and pictures.

The Mesoamerican Reef (MAR) spans more than 1,000 km along the coasts of Mexico, Belize, Guatemala and Honduras and supports the local economies and culturally rich livelihoods of over two million people. The Healthy Reefs Initiative (HRI), through a precedent-setting conservation partnership of over 70 partner organizations, is working to improve the health of this diverse ecosystem through science-based management recommendations.

Over the past 12 years, the Healthy Reefs Initiative (HRI) collectively and quantitatively assesses reef health and informs science-based management recommendations every 2 years. Today we are launching our Mesoamerican Reef Data Explorer Platform in collaboration with Atlantic and Gulf Rapid Reef Assessment (AGRRA) where users will be able to visualize the change on reef health data collected over 10 years, between 2006 and 2016, through interactive maps and pictures. Data is accessible by site and by indicator used to determine the Reef Health Index: coral cover, macroalgae cover, herbivorous and commercial fish biomass.

Our reliable measures of reef condition allow us to identify the most urgent threats and responses. HRI training workshops continue to strengthen scientific capacity. Our partners are scaling-up and improving management in 47 MPAs spanning almost 60,000 km2. Through our Regional Coral BleachWatch Network, we have quickly mobilized and supported teams of partners across the region to monitor coral bleaching.

The major threats such as coral bleaching events as well as the new rapid coral tissue loss disease detected since summer 2018 in Mexico, are also available in the Mesoamerican Reef Data Explorer Platform.

In the last 2018 Report Card on the Health of the Mesoamerican Reef, we showed an improvement on 3 of 4 indicators over the decade, including coral cover (18%), herbivorous fish (2,731g/100m2) and commercial fish (909g/100m2). The only indicator with no improvement was fleshy macroalgae, almost doubled from 12% in 2006 to 23% in 2016. Overall, the Reef Health Index improved from 2.3 to 2.8 over the past decade. Compared to global trends of widespread reef decline, these encouraging results of recovery are a testament to the benefits of collaborative management.

Each country’s unique history and management efforts affect the status of the four reef indicators. These trends are an urgent Call to Action for country specific management responses. The platform shows a 10-year perspective on reef health and conservation aimed to ensure our reefs will endure and thrive into the future.

Learn more at: /

For more information contact us at:

New fish species discovered: Striped Hamlet

Striped Hamlet (Hypoplectus liberte), Fort Liberte Bay, Haiti, © Ken Marks 2018Striped Hamlet (Hypoplectus liberte), Fort Liberte Bay, Haiti, © Ken Marks 2018

In the fall of 2018,   AGRRA Database Manager Ken Marks helped Benjamin Victor describe a new fish species, Striped Hamlet (Hypoplectus liberte) in Fort Liberte Bay on the northern coast of Haiti that had been initially discovered in 2015.

While surveying with our partners, The Nature Conservancy, AGRRA fish surveyors Dave Grenda and Ken Marks, also the AGRRA Database Manager, noticed this unusual Striped hamlet in Fort Liberte Bay on Haiti’s northern coast. Striped Hamlet (Hypoplectus liberte), the newest member of the fascinating hamlet family as photographed in the muddy sponge-dominated bay where this species was discovered in 2015, was finally described in 2018.

Initially thought to be an novel hybrid (hybrids are common in this genus), the sightings of many individuals soon made it apparent that this was a new species endemic to just that bay.

For more information on this discovery, see Journal of the Ocean Science Foundation,  and Reef Builders.

See the 2016 report from the work conducted in Haiti:  Haiti Three Bays National Park Ecological Baseline . This report is also accessible from the Resources page.

Seasons Greetings 2018

Black Grouper, Eleuthera, The Bahamas. ‘Train The Trainers’ workshop, May 2018. (c)  Ken Marks


Thank you to all our partners for your continued support and inspiration to help conserve Caribbean coral reef ecosystems.

With your collaboration and participation, our collective 2018 accomplishments included:

AGRRA Database Manager Kenneth Marks helped Benjamin Victor describe a new fish species, Striped Hamlet (Hypoplectus liberte) in Fort Liberte Bay on the northern coast of Haiti that had been initially discovered during an AGRRA survey in 2015.

The completion of 356 surveys in eleven countries including Jamaica, Grenada, Saint Vincent, Antigua, Dominican Republic, Haiti, Turks & Caicos, Mexico, Honduras, Belize and Guatemala.

An updated AGRRA database that now includes 2859 total surveys from 29 countries.

Twelve new AGRRA trainers, representing nine organizations across five countries, were certified at a “Train the Trainers” workshop at the Cape Eleuthera Institute in The Bahamas.

The development of new interactive ARC GIS StoryMaps and tools for Healthy Reefs Initiative and GCFI MPA Connect.

Training young scientists of SCUBAnauts International and conducting coral disease surveys in the Lower Florida Keys.


Challenging this year was the increased incidence of coral disease. Thank you to everyone who has responded so far, and please continue to send us observations and photographs of diseased coral outbreaks.

The year ended on an encouraging note through our participation in the Reef Futures 2018  conference in December, where nearly 500 practitioners and scientists gathered to share innovative approaches to coral restoration.

We look forward to continuing our partnerships with you to expand stewardship and understanding of our coral reefs in the Caribbean in 2019.

Happy Holidays! 
Philip Kramer, Patricia Kramer, Judith Lang, Kenneth Marks
Shirley Gun, Lynnette Roth