New research results, expanded restoration efforts target stony coral tissue loss outbreak

Florida’s coral reefs are facing an unprecedented, deadly and rapidly spreading coral disease outbreak — putting them at risk of functional extinction — and Mote Marine Laboratory scientists are accelerating their innovative efforts to secure the reefs’ future.

As of March 2019, stony coral tissue loss disease is plaguing nearly half the coral species on the Florida Reef Tract, with mortality rates frequently exceeding 80 percent. The outbreak stretches from Martin County to Key West, with potentially similar disease signs being investigated at other Caribbean reefs. Susceptible corals include maze, brain, boulder and other species groups that form the essential foundations of the Florida Reef Tract, an economic engine worth $8.5 billion and supporting 70,400 jobs.

Recognizing these high stakes, scientists at Mote — an independent, nonprofit institution — are raising the bar on disease research and responsive reef restoration, as leaders within a state-federal-nongovernment Disease Advisory Committee of more than three dozen partners focused on the outbreak. As of March 2019, Mote is: undertaking the first year of its new Florida Keys Coral Disease Response & Restoration Initiative; taking care of rescued coral fragments from sites ahead of the disease front and initiating longer-term coral gene banking efforts; reporting its new research results on bacterial changes in the infected corals; and implementing and evaluating science-based coral restoration as a key recovery strategy, with Mote co-leading a multi-institutionRestoration Trials Team.

  • On April 13, the public can meet Mote scientists on the front lines of the disease response effort during Mote’s Ocean Fest: A Community Celebration in Key West. Details:

Below are updates from Mote’s Elizabeth Moore International Center for Coral Reef Research & Restoration (IC2R3) from 2018 into early 2019. In each effort, Mote is coordinating with the Florida Fish and Wildlife Conservation Commission (FWC), Florida Department of Environmental Protection (DEP), National Oceanic and Atmospheric Administration (NOAA) and others.

“There is no stopping this coral plague from running its course — it is highly unlikely that our devastated coral populations will be able to execute a natural recovery on their own,” said Mote President & CEO Dr. Michael P. Crosby. “That means conservation strategies alone cannot solve this dilemma. Mote has proposed a bold science-based coral disease response and restoration initiative that is essential to actively assist the recovery of this ecosystem. The Florida Legislature is currently considering a $2 million request for launching our proposed collaborative initiative, and Senator Marco Rubio was instrumental in recently shepherding a Congressional $5 million addition to NOAA’s budget to help support our initiative to respond to this environmental disaster.”

“Mote is one of several dedicated organizations in Florida taking the lead in ensuring the Florida Reef Tract will be enjoyed by future generations,” said Senator Rubio. “Floridians are grateful for the expertise and passion Mote researchers bring to their work, and I know Mote will make a meaningful difference with the unprecedented federal resources for the restoration of our reefs that I secured as a member of the Senate Appropriations Committee. South Florida’s economy depends on it.”

“Our reefs are a vital resource for many of our Florida communities and we must take bold steps to respond to coral disease and protect this vital ecosystem,” said State Representative Holly Raschein, District 120. “Mote’s valuable work has never been more important in ensuring that we use sound science-based solutions to ensure that we can restore and protect our reefs, for our residents, tourists and future generations.”

Dr. Erinn Muller, IC2R3 Science Director and Manger of Mote’s Coral Health & Disease Research Program, is leading Mote’s pursuit of those science-based solutions.  “We are screening our native coral genotypes for resistance to stressors, and we have some genotypes highly resistant to stony coral tissue loss disease,” Muller said.  “Through restoration, we now have the power to incorporate that trait within our population, along with genetic diversity to ensure resistance to a variety of stressors. Now is a critical time. Either we’re going to lose our coral reefs in the next decade, or were going to make sure they survive and continue the functions that are so critical for our livelihoods and our wellbeing.”

Mote’s Dr. Erinn Muller discusses coral health and disease with Sen. Marco Rubio in February 2019. Credit: Conor Goulding/Mote Marine Laboratory

Progress so far

  • In pursuit of the pathogen(s):
    Scientists suspect that stony coral tissue loss disease is bacterial and waterborne, but confirming the pathogen(s) and understanding the disease process remain important challenges. Now, a collaborative study funded by the Environmental Protection Agency and conducted by Mote, NOAA’s Atlantic Oceanographic and Meteorological Laboratory, and FWC, is chipping away at those challenges.

    “Some of the new research coming out of our lab, that’s hot off the press, suggests that there is a unique bacterial signature of these corals after they are sick,” Muller said, noting that corals normally carry bacteria, but bacteria are diverse and can be helpful or harmful. “Even corals that have survived the event but were exposed to the disease have a certain bacterial signature that’s different from those of corals from reefs that haven’t been exposed.”

    Project partners collected 75 coral tissue samples and 90 samples apiece of water and sediment, from three site types: healthy, diseased and previously diseased but without active disease still present. From the samples, they isolated and analyzed a specific stretch of DNA that varies among different bacteria. They found that bacterial groups of the corals differed significantly among the healthy, diseased and previously diseased sites, and the bacteria in the scientific orders known as Rhodobacterales and Rhizobiales may play an important role in the stony coral tissue loss disease.

    “So we know there are a few different groups of bacteria associated with this disease,” Muller said. “Whether they represent primary pathogens or a secondary response to something else that is the primary pathogen, we don’t know yet.”

    The project also tested how bacterial communities of the sediments and water differed among the same sites to try and identify potential reservoirs of putative pathogens. Water in diseased sites had greater numbers of bacteria in the orders Rhodobacterales, similar to the bacteria found within the diseased corals. These results indicate that diseased reefs may have a specific bacterial signature within the water column.

    This year, project partners are leading disease-transmission experiments in the lab to study the bacterial changes in more detail, observing how bacterial markers shift as the coral gets exposed, sickens, and dies or recovers.

  • Resilience and restoration
    Several years ago, the future of coral ecosystems was dismal — that has now changed dramatically,   Crosby said: “While many coral scientists and environmental activists around the world saw coral bleaching events and devastating coral diseases of recent years and concluded that it’s impossible to replace a dead 50- or 100-year old coral in a decade, I contend that now is not the time for scientists to throw in the towel. Investing time and resources, and conducting world-class research into restoring coral reefs is not a choice, it is a necessity. Mote scientists have developed a novel micro-fragmentation and re-skinning technique that can bring back to life the massive and slow growing corals that are vital reef building structure — and we can do this in just one or two years instead of hundreds of years it would take nature to rebuild a reef on its own. This is something of a Coral Lazarus Effect.

    Muller explained, “We take fragments of these corals, chop them into tiny microfragments, and allow genetically identical microfragments to fuse and then re-skin the skeletons of larger corals. Microfragmentation accelerates their growth rate by 40-50 times what you’d see in nature.”

    This method is especially powerful when scientists choose genetically diverse corals — which, as a group, have a larger assortment of stress-resistant traits — and promote their best traits through controlled sexual reproduction efforts.

    Over the years, Mote scientists have raised and restored more than 43,000 corals to depleted reefs in the Florida Keys. In lab studies, some of the Mote-raised coral genotypes (genetic varieties) show resistance to tissue loss disease carried in the water, only becoming sick after directly touching infected corals. At least one Mote-tested genotype of mountainous star coral appears to resist the disease altogether.

    Now, Mote is investigating whether lab-tested corals will continue thriving once planted on the reef. This is one of many efforts overseen by a Restoration Trials Team co-led by Mote and DEP, with members from NOAA, FWC, U.S. Geological Survey, Nova Southeastern University, Florida Aquarium, Coral Restoration Foundation, The National Park Service, The Nature Conservancy and Coral Restoration Consortium.

    In late 2018 Mote outplanted about 2,500 coral colonies of three species susceptible to tissue loss disease — about half into the diseased zone and the other half into the vulnerable zone that showed no disease signs. Findings will inform best practices for future restoration. Early results show that less than 1 percent of corals planted in the disease zone and none of the corals planted in the vulnerable zone show signs of the disease.

  • Caring for rescued corals
    This month, Mote Aquarium in Sarasota received 107 coral colonies rescued from vulnerable areas yet to show signs of stony coral tissue loss disease. This effort, led by FWC and NOAA, involves distributing corals to qualified caregivers, with the goal of restoring them to reefs when and where disease conditions permit restoration.

    Muller said: “As part of the Restoration Trials team, we will help guide the Coral Rescue project by helping them determine when it may be safe for these corals to return to the wild.”

    Mote is able to care for the rescued corals thanks to a grant of more than $27,000 from the National Fish and Wildlife Foundation.* Mote Aquarium and Florida Aquarium, each housing some rescued corals, are accredited members of the Association of Zoos and Aquariums (AZA). The AZA accredits only those facilities that meet its excellent standards for animal care, safety, involvement in conservation and research, and much more.

Super-charging Mote’s response effort

Building upon progress to date, this year Mote launched its Florida Keys Coral Disease Response & Restoration Initiative, a bold and innovative response against multiple threats to Florida’s reefs.

Over three years, Mote and partners will:

  • Plant approximately 70,000 coral fragments of diverse, endemic genetic varieties, emphasizing those demonstrated to be resilient to coral disease or climate change conditions — another serious and widespread threat;
  • Advance the important efforts already begun: conducting necessary research to identify naturally resilient, endemic genetic varieties of coral species, cross-breed them in a targeted way for healthy genetic diversity, and investigate why they are resilient;
  • Establish and maintain quality control of life-support systems in a remote, secure, inland, coral gene bank in recirculating seawater infrastructure to ensure the long-term viability and persistence of threatened coral species and their genetic diversity;
  • Establish an isolated, “clean room” laboratory for coral disease research — a necessity for studies of contagious diseases whose ability to spread is not fully understood; and
  • Implement multi-year monitoring and analyses to scientifically evaluate ecological impacts and benefits of restoration.

One of the most visible efforts this summer will be creating a secure coral gene bank at Mote Aquaculture Research Park in eastern Sarasota County, Florida.

“This will be a safe haven for coral genotypes being used in restoration and research,” Muller said, noting that Hurricane Irma provided a reminder of why corals should be protected in multiple locations. Mote’s IC2R3 is Category-5 hurricane resistant, but its outdoor raceways required major repairs.

She continued: “We provide a lot of corals for research already, but every time we provide a coral for research, it’s one fewer that we can put on the reef. So now we’ll have the new gene bank in Sarasota County focus more on research, and we’ll have our propagation in the Florida Keys continue focusing more on restoration.”

Mote’s Initiative includes partners from NOAA’s FKNMS and its Coral Reef Conservation Program, Biscayne National Park, DEP, The Nature Conservancy and others.

These monumental efforts are possible thanks to a combination of philanthropic giving, State of Florida funding and Mote’s recent grant of nearly $1.5 million from the National Coastal Resilience Fund, a partnership of the National Fish and Wildlife Foundation*, NOAA, Shell Oil Company and TransRe.

The grant challenges Mote to raise matching funds. To support this important initiative, visit, click “Donations,” and under “Designation,” select “Coral reef research & restoration.”

New potential support is also on the horizon in Florida. In early 2019, State Rep. Kristin Jacobs introduced House Bill 2899, and State Senator Ben Albritton introduced a matching funding request (LFR 1301), both calling for $2 million in appropriations to FWC for a Mote-led coral disease response & restoration initiative in fiscal year 2019-20. If funded, this will enable 50,000 corals to be produced for planting, creating almost 100 acres of restored reefs and expanding the scope of Mote’s gene banking and other crucial efforts.

Envisioning a state-to-national coral gene bank

Mote’s efforts supported by the National Coastal Resilience Fund, the proposed efforts being considered for State of Florida appropriations, each represent important “seeds” for Mote’s longer-term vision of vastly expanded coral gene banking, enabling new levels of research and restoration.

“Ultimately, we envision that the gene bank we are creating this year at Mote Aquaculture Research Park will be the seed for our longer-term development of a Category-4  or -5 hurricane-resistant, expanded coral gene bank at that location, ideally with every coral genotype we are able to culture represented there in triplicate,” Crosby said. “Mote has the knowledge, passion and vision to develop a gene bank that can host representative genotypes of every coral species found in Florida, and grow that to become a national gene bank for every coral species in the United States.”

*The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the opinions, views, or policies of the National Fish and Wildlife Foundation.  Nothing contained herein constitutes an endorsement in any respect by the National Fish and Wildlife Foundation.