ArticlePDF Available

REEF ENCOUNTER Spread of the new coral disease "SCTLD" into the Caribbean: implications for Puerto Rico

  • Institute for Socio-Ecological Research (ISER), Coastal Survey Solutions LLC (CSS)


The article presents a summary of the current situation and spread of the new coral disease Scleractinian Coral Tissue Loss Disease (SCTLD) in the Caribbean and in Puerto. Rico.
The News Magazine of the International Coral Reef Society
Reef Currents: SCTLD in the Caribbean implications for Puerto Rico
38 | P a g e VOLUME 34 NUMBER 1 December 2019
Spread of the new coral disease “SCTLD” into the Caribbean:
implications for Puerto Rico
E Weil1, EA Hernández-Delgado2,3,4, M Gonzalez5,6, S Williams7, S Suleimán-
Ramos4, M Figuerola1,5 and T Metz-Estrella5,7
1Department of Marine Sciences, University of Puerto Rico, Road 304, La Parguera, PR 00667; 2Department of Environmental
Sciences, University of Puerto Rico, 17 Ave Universidad STE 1701, San Juan 00925-2537, Puerto Rico; 3Center for Applied Tropical
Ecology and Conservation, University of Puerto Rico, 17 Ave Universidad STE 1701, San Juan 00925-2537, Puerto Rico; 4Sociedad
Ambiente Marino, PO Box 22158, San Juan 00931-2158, Puerto Rico; 5Department of Natural and Environmental Resources, PO
BOX 366147, San Juan Puerto Rico, 00936; 6Nova Southeastern University, 3301 College Avenue, Fort Lauderdale-Davie, Florida
33314; 7Institute for Socio-Ecological Research, Inc, PO Box 3151, Lajas, Puerto Rico 00667
The ongoing deterioration and significant decline in live coral cover and diversity in coral reef communities
worldwide is strongly associated with increasing water temperatures linked to Global Climate Change, aided by
anthropogenic activities (Harvell et al. 2004, 2007, 2009; Weil and Rogers 2011; Maynard et al. 2016; Woodley et al.
2016). In the Wider Caribbean, major community structure and function decline was marked by two region-wide,
concurrent, highly virulent disease epizootics in the early 1980’s. These events almost wiped out two foundational
scleractinian species (Acropora palmata and A. cervicornis), and the keystone sea urchin Diadema antillarum. White
band disease (WBD) affected the acroporids and was caused by a complex of vibrio bacteria (Gil-Agudelo et al. 2006).
The Diadema mass mortality had all the trademark characteristics of a virulent, transmissible, bacterial or viral
infection, but the putative pathogen (pathogens) was never identified (Lessios 2016). Populations of both acroporids
and sea urchins suffered over 95% mortalities throughout the wider Caribbean (Gladfelter 1982; Lessios et al. 1984a,b;
Aronson and Precht 2001; Lessios 2016), followed by a cascade of ecological consequences (significant loss of live
coral cover, primary productivity, spatial complexity, biodiversity and fecundity; loss of ecological functions, increase
in algal cover and biomass, etc.), ending in a shift from coral- to algal-dominated communities and the loss of
ecological services to other tropical marine communities and to human beings (Aronson and Precht 2001; Weil and
Rogers 2011). Several other disease-induced mass mortalities of other cnidarians, as well as of massive, plate and
nodular reef-building genera, have in the last 30 years resulted in additional loss of biomass, diversity and live coral
cover on many Caribbean reefs (Miller et al. 2009; Weil et al. 2009a; Weil and Rogers 2011; Bastidas et al. 2011; Weil
et al. 2017).
More recently, a presumed new “white-plague type” disease, killing large numbers of corals in a short time, was
reported from southeastern Florida in 2014 (Precht et al. 2016; Walton et al. 2018). It followed dredging operations
(2013-2015) in the Port of Miami channel, that resulted in high sedimentation and turbidity near “ground zero” (Miller
et al. 2016), and came after Summer-Fall high thermal anomalies that led to extensive bleaching across the Florida
Reef Tract (Manzello 2015; Walton et al. 2018). Therefore, it is possible that the pathogen(s) could have been released
from sediment disturbance, or that pathogen virulence and/or host susceptibility were affected by the high
temperatures, or both. Often new disease outbreaks occur following a change in host-parasite biological or ecological
relationship, the introduction of a novel pathogen(s) in susceptible host populations, the emergence of newly evolved
pathogens and/or changes in environmental conditions that alter the microbiome/host physiological equilibrium,
fostering increased pathogen virulence, transmissibility and coral mortality (Daszak et al. 2000, 2001; Harvell et al.
2007, 2009; Weil and Rogers 2011; Woodley et al. 2016; Aeby et al. 2019).
This apparently new disease has been called “Stony Coral Tissue Loss Disease” (SCTLD). It is waterborne, highly
transmissible and highly virulent (rapidly kills coral tissues at a rate of 3-4 cm/day), affecting at least 22 foundational,
scleractinian species (generalist), both usually characteristic traits of a novel pathogen (Weil and Rogers 2011).
Furthermore, in Florida and St. Thomas, most diseased coral lesions treated with an antibiotic (amoxicillin) showed
The News Magazine of the International Coral Reef Society
Reef Currents: SCTLD in the Caribbean implications for Puerto Rico
VOLUME 34 NUMBER 1 December 2019 39 | P a g e
signs that disease progression had slowed or even stopped (SCTLD, Florida Keys National Marine Sanctuary 2018; M.
Brandt pers. comm.). These characteristics indicate that a bacterium or a complex of bacteria might be responsible,
although the putative agent(s) have yet to be identified (Meyer et al. 2018; Aeby et al. 2019). Similarities of SCTLD
signs with those of white plague disease type II (WPD-II) (Richardson et al. 1998; Weil and Rogers 2011; Woodley et
al. 2006; SCTLD-Report-Florida Keys National Marine Sanctuary) has produced uncertainty when attempting to
identify the disease in the field. Some differences with WPD include: acute multifocal infections on single colonies,
tissue and mucus sloughing, and more rapid tissue mortality. These symptoms may not, however, be observed in all
colonies, or in a single survey, but only in repetitive surveys of the same colonies.
Both of the above diseases are “generalists”, affecting multiple species, although species susceptibility seems to
vary. Of the 22 species reported with SCTLD signs, most of them are important reef-building species in the Caribbean.
Six species seem to be highly susceptible in Florida (prevalence > 85%) and other localities: Meandrina meandrites,
Colpophyllia natans, Dichocoenia stokesii, Pseudodiploria strigosa, P. clivosa and Dendrogyra cylindrus. Five species
showed prevalence values higher than 45% in Florida (Eusmilia fastigiata, Diploria labyrinthiformis, Montastraea
cavernosa, Stephanocoenia intersepta and Orbicella faveolata) (Meyer et al. 2018; Aeby et al 2019; SCTLD-Report-
Florida Keys National Marine Sanctuary-2018). Four susceptible species (D. cylindrus, O. faveolata, O. franksi and O.
annularis) are listed as threatened under the United States Endangered Species Act. The Orbicella spp. complex,
Montastraea cavernosa and Siderastrea siderea are listed under intermediately susceptible to SCTLD, however,
species susceptibility could vary geographically and temporally as the disease moves through the Caribbean. Corals,
like many other modular cnidarians, do not show many different visible structural/ physiological responses to
diseases, specially, within the white band-white plague syndromes. These syndromes produce a white, clean skeletal
band after the die-off of the tissue, between the normal-looking tissue and the colonizing turf algae. The band width
Table 1. Chronological dispersion of SCTLD in Florida and the northern Caribbean, and
appearance of localized disease outbreak in Puerto Rico
2014 - First reported off the coast of Miami-Dade County, Florida
2015 - Expanded to Biscayne National Park and north to Broward County in Florida
2016 - Continued spreading in Florida, south to the Upper Keys and north to Palm Beach County
2017 - Moved south into the Middle Keys and to the northern latitudinal edge of the Florida Reef Tract
2017 - First reports from the north coast of Jamaica in July 2017
2018 - Reached the Lower Keys in Florida, more reports made from Jamaica, new reports from Mexico,
Belize and St. Maarten
Spring 2018: New observations from the northwest coast of Jamaica
July 2018: First reports from Quintana Roo, Mexico
October 2018: First report in the eastern Caribbean, St. Maarten
2019 - Moved to the southwest end of the Lower Keys, not into the Dry Tortugas National Park. AGRRA
created a map to report and track SCTLD throughout the Caribbean:
January 2019: First reports at Flat Cay, St. Thomas, U.S. Virgin Islands
March 2019: Reported at more locations in St. Maarten; First report in northwest coast of the
Dominican Republic
June 2019: First report from Belize
August 2019: First report from Saint Eustatius
2019 - First reports of a localized disease outbreak off the eastern coast of Puerto Rico
November 2019: Reports of highly virulent tissue loss disease affecting several corals in
Tamarindo Chico reef, Culebra, Puerto Rico. Many colonies with signs similar to those reported
for SCTLD.;
The News Magazine of the International Coral Reef Society
Reef Currents: SCTLD in the Caribbean implications for Puerto Rico
40 | P a g e VOLUME 34 NUMBER 1 December 2019
is determined by the balance between how fast the tissue is dying (virulence) and how fast algal turf is colonizing.
Although similar signs have been observed across sites, we cannot assume that the observed signs represent the same
disease produced by the same pathogen (s), as this may not be the case all across the local and/or geographic
distribution of the disease (Sunagawa et al. 2009). Once the pathogen(s) of SCTLD has been determined, diseased
colonies in all the reported localities will have to be tested to confirm whether all cases represent the same disease.
In Florida in 2015-2017 SCTLD spread quickly (at a rate of 710 km/month) along the Florida Reef Tract both south
and north of “ground zero”. Since then it has expanded to several northern Caribbean localities (Table 1 -; producing
significant mortalities in populations of the susceptible species in all localities where it has been observed, raising
concerns about the overall impact it could have on the already declining coral reef communities across the region
(Lunz et al. 2017; Florida Keys National Marine Sanctuary 2018; Meyer et al. 2019; Aeby et al. 2019). The dispersion
pattern of SCTLD does not seem to follow directly the direction of local and regional currents from “ground zero”,
since it has shown up in localities in directions against the normal current, and/or at sites thousands of km apart. Since
the disease is waterborne and highly infectious, it would be expected to follow the direction and speed of ocean
currents, however it was reported from Jamaica in July 2017 with no reports from Cuba or the Cayman Islands. It was
reported in Quintana Roo, Mexico in July 2018 and in Belize in June 2019.
The disease was first observed in St. Thomas, USVI, in January 2019, before it was observed in the Dominican
Republic and then in the Turks and Caicos Islands. It quickly spread along the southwest coast of St. Thomas, producing
highly localized mortality of the susceptible species, and has been documented as spreading northeastward as well.
There are no reports of outbreaks of SCTLD from the Bahamas, Cuba or other localities intermediate to the
southernmost areas where it has been reported, leading some researchers to postulate that cruise/cargo ships or
“contaminated” dive equipment might be involved in SCTLD dispersion. There might be other
biological/oceanographic explanations for this discontinuous dispersion pattern. For example, the pathogen (s) might
be part of the normal microbiome of the holobiont, as mutualistic components, or the sediment and substrate, and
become virulent given certain changes in environmental conditions, host susceptibility or both.
Oceanographic current models projected that as a waterborne pathogen SCTLD would reach Puerto Rican waters,
close to Vieques or Culebra, by May-June 2019. It was not however until October 2019 that a few, isolated colonies
of some of the susceptible species were observed with the described SCTLD signs in Culebra. Between March and
August 2019 several colonies of S. siderea were observed with signs of what looked like acute WPD or SCTLD on many
reefs in the east (Ceiba, Humacao, Culebra and Vieques) and west (Cabo Rojo, Guanica and Mona) of Puerto Rico.
Some colonies showed mucus and tissue sloughing, and fast, multifocal, acute rapid loss of live tissue, similar to SCTLD
signs. In what seems a systemic immune response, several colonies became dark purple or just dark (Fig. 2). However,
there were no other diseased species and no signs of an outbreak, which could indicate that this is a different disease
affecting only S. siderea, possibly induced by the thermal anomaly hitting the area this year (Miller et al. 2009; Weil
and Rogers 2011). By November 2019, a minor, localized outbreak of what looked like SCTLD also affected many
colonies of several species at Punta Tamarindo Chico reef (18°18.578’N - 65°19.040’W) on Culebra Island, off the
eastern coast of Puerto Rico (Fig. 1.). Curiously, colonies with typical multifocal signs of SCTLD were not observed in
November 2019 at any of the 29 random sites surveyed in Culebra for NOAA’s National Coral Reef Monitoring Program
(NCRMP). So far, Tamarindo Chico reef is the only locality reported to have characteristic signs of SCTLD in Puerto
Water temperatures have been above average this year for the northeastern Caribbean, reaching seven Degree
Heating Weeks (DHW) (local measurements and NOAA) by November 2019. In September 2019, this thermal anomaly
induced yet another extensive bleaching event that expanded all over Puerto Rico’s shallow and upper-mesophotic
coral communities by November. Bleached corals make it difficult to distinguish the signs of SCTLD or WPD. Bleaching
prevalence measured around Culebra during the NCRMP surveys in November 2019 varied between 50-62% (partially
to totally bleached), with the most susceptible species in this area being O. annularis, O. faveolata, P. strigosa, D.
labyrinthiformis and S. siderea. During this period hard corals in Culebra were possibly more susceptible to disease
The News Magazine of the International Coral Reef Society
Reef Currents: SCTLD in the Caribbean implications for Puerto Rico
VOLUME 34 NUMBER 1 December 2019 41 | P a g e
due to thermal stress. Per anecdotal evidence, SCTLD lesion progression rates appeared to slow down or even stop
during periods of higher water temperatures and/or coral bleaching in Florida and the USVI; however the relationship
between these factors is still uncertain (Aeby et al. 2019).
Consecutive surveys in Tamarindo
Chico reef showed a significant
increase in disease prevalence in
SCTLD susceptible species, from 4% in
October, to 50% in November, and
74% in December (Hernández-
Delgado and Suleimán-Ramos,
unpublished data). Similar to the
initial stages of SCTLD in St. Thomas,
acute impacts have remained highly
localized across a single reef site,
affecting mostly meandroid species.
Disease prevalence varied across
species: >50% in D. cylindrus, 80% in P.
strigosa, P. clivosa, and D.
labyrinthiformis, and >90% in M.
meandrites and S. siderea, which, as
mentioned above, have shown signs
of disease well before this localized
outbreak. The disease indiscriminately
affected wild and nursery-restored
colonies of D. cylindrus,
Pseudodiploria spp., D.
labyrinthiformis, C. natans, M.
meandrites and S. siderea. It has also
affected colonies of D. cylindrus and E.
fastigiata on adjacent coral farms, but
with a significantly lower prevalence
(<5%). With the collaboration of Nova
Southeastern University, the NGO
Sociedad Ambiente Marino and a
provisional permit provided by the
Puerto Rico Department of Natural
and Environmental Resources (DNER),
preliminary testing with an
experimental treatment of
amoxicillin antibiotic in CoreRX
Base2B yielded promising results,
halting disease progression in 90% of
treated colonies of Pseudodiploria
spp., D. labyrinthiformis, Colpophyllia
natans, D. cylindrus, M. cavernosa and
S. siderea (N = 50 colonies).
One of the most effective responses documented thus far, from Florida and St. Thomas, has been the use of
amoxicillin; but given the characteristics of SCTLD, there is a pressing need to increase significantly the number of
colonies treated per locality (and to text other antibiotics) in order to minimize the risk of infection spreading to other
Figure 1. Photographs of diseased colonies of species susceptible to SCTLD in
Tamarindo Chico, Culebra. Several small colonies of P. strigosa with multi-focal
infected areas (A). Colony of P. clivosa with fast advancing, multi-focal infections
(B). Medium sized P. strigosa with two rapidly advancing diseased areas (C).
Almost 100% mortality in small D. cylindrus (D). Mucus and tissue sloughing in S.
siderea (E). Rapidly advancing white band area in D. labyrinthiformis (F) and M.
cavernosa (G). Small colony of C. natans that is almost 100% dead in a short time
The News Magazine of the International Coral Reef Society
Reef Currents: SCTLD in the Caribbean implications for Puerto Rico
42 | P a g e VOLUME 34 NUMBER 1 December 2019
reefs. There is also a need to reduce,
if possible, the numbers of
recreational visits (i.e., SCUBA diving,
snorkeling, kayaking) to the affected
sites and to implement strict
equipment disinfection protocols and
also initiate outreach activities to
inform and educate the stakeholders
and any visitors. The DNER has been
participating in the USVI-SCTLD
status monthly calls even before
suspicious colonies were identified in
Puerto Rico. With the support of the
DNER, SCTLD education and outreach
materials generated by other
jurisdictions have been translated
into Spanish and shared with relevant
audiences to increase awareness and
promote SCTLD prevention. In
addition, theoretical and practical
training on SCTLD was held by Sea
Grant FL, Sea Grant PR and the DNER
for coral reef experts, dive shops,
fishermen and other stakeholders.
Direct communication was also
established with tourist operators in
Vieques, where SCTLD was expected
to show-up first, following UVI
Several other Federal and local
government agencies, Institutions
and NGOs [the National Oceanic and
Atmospheric Administration (NOAA),
the University of Puerto Rico in San
Juan, Sociedad Ambiente Marino
(SAM), HJR Reefscaping, Coastal
Survey Solutions, and the
Department of Marine Sciences
(DMS) of University of Puerto Rico,
Mayaguez] have also collaborated to
educate, prevent, prepare, and
respond to the threat of SCTLD on Puerto Rico’s coral reefs. By staying in contact with key stakeholders in both Florida
and the USVI, these institutions have had the benefit of learning from other jurisdictions’ experiences to develop
response plans, protocols and “rapid response teams” (RRT) for Puerto Rico. The RRT are trained on how to identify
the disease and differentiate it from other coral diseases and bleaching, how to treat diseased colonies, and how to
decontaminate diving equipment after dives in disease-impacted areas, among other response activities. Such training
and preparedness is crucial given the threat of SCTLD to coral reefs in Puerto Rico. Researchers are exploring other
ways to control the disease.
Figure 2. Diseased colonies of S. siderea around Puerto Rico, some before the
outbreak of the possible SCTLD outbreak was reported in Tamarindo Chico,
Culebra. Two large diseased colonies with multifocal infected areas and evidence
of fast mortality in Guaniquilla, west coast of Puerto Rico (A, B). Mucus and tissue
sloughing in diseased S. siderea (C, D). Colony of S. siderea with multiple signs of
dark spots disease and multi-focal infections of a white-plague type that could be
SCTLD (E). A recently fast killed colony of M. meandrites, with skeletal structure
covered by sediment and signs of some turf colonization (F).
The News Magazine of the International Coral Reef Society
Reef Currents: SCTLD in the Caribbean implications for Puerto Rico
VOLUME 34 NUMBER 1 December 2019 43 | P a g e
We would like to thank our colleagues Karen Neely (Nova Southeastern University), Maurizio Martinelli (Sea Grant FL), Dana Wusinich-Mendez
(NOAA) and the Florida team; Dr. Marilyn Brandt (University of the Virgin Islands), Leslie Henderson (NOAA) and the USVI team; and Dr. Judith
Lang (AGRRA) for all of their continued support, advice, and for providing us with treatment materials. Ernesto Diaz and the Puerto Rico Dept.
of Natural Resources (DNER), Sociedad Ambiente Marino, Kimberly Edwards (NOAA) and Coastal Survey Solutions (NCRMP), Dept. of Marine
Sciences, UPRM, and NSF (Grant # 2000863) provided logistical and partial financial support.
Aeby GS, Ushijima B, Campbell JE, Jones S, Williams GJ, Meyer JL, Häse C, Paul VJ (2019) Pathogenesis of a tissue loss disease affecting multiple
species of corals along the Florida Reef Tract. Front. Mar. Sci. 6: 678. doi: 10.3389/fmars.2019.00678
Aronson RB, Precht WF (2001). White-band disease and the changing face of Caribbean coral reefs. In: Porter JW, editor. The ecology and
etiology of newly emerging marine diseases. Kluwer, pp 2538
Daszak P, Cunningham AA, Hyatt AD (2000). Emerging Infectious Diseases of Wildlife Threats to Biodiversity and Human Health. Science 287:
443449. doi: 10.1126/science.287.5452.443
Daszak P, Cunningham AA, Hyatt AD (2001) Anthropogenic environmental change and the emergence of infectious diseases in wildlife. Acta
Trop 78: 103116. doi: 10.1016/s0001-706x(00)00179-0
Florida Keys National Marine Sanctuary (2018) Case Definition: Stony Coral Tissue Loss Disease (SCTLD). National Oceanic and Atmospheric
Administration. stony-coral-tissue-loss-disease-
Gil-Agudelo DL, GW Smith, Weil E (2006) The white band disease type II pathogen in Puerto Rico. Rev. Biol. Tropical 54: 59-67
Harvell D, Aronson R, Baron N, Connell J, Dobson A, Ellner S, Gerber K, Kim K, Kuris A, McCallum H, Lafferty K, McKay B, Porter J, Pascual M,
Smith G, Sutherland K, Ward J (2004) The rising tide of ocean diseases: unsolved problems and research priorities. Front Ecol Environ: 2:375
Harvell CD, Jordan-Dahlgren E, Merkel S, Rosenberg E, Raymundo L, Smith G, Weil E, Willis B (2007) Coral disease, environmental drivers, and
the balance between coral and microbial associates. Oceanography: 20:17295
Harvell CD, Altizer S, Cattadori IM, Harrington L, Weil E (2009) Climate change and wildlife diseases: when does the host matter the most?
Ecology 90: 91220
Lessios HA (2016). The Great Diadema antillarum die-off: 30 Years Later. Annu Rev Mar Sci. 8: 267-283
Lessios HA, Cubit JD, Robertson RD, Shulman MJ, Parker MR, Garrity SD, Levings SC (1984a) Mortality of Diadema antillarum on the Caribbean
coast of Panama. Coral Reefs 3: 173-182
Lessios HA, Robertson DR, Cubit JD (1984b). Spread of Diadema mass mortality through the Caribbean. Science 226: 335-337
Lunz K, Landsberg J, Kiryu Y, Brinkhuis V (2017) Investigation of the Coral Disease Outbreak affecting Scleractinian Coral Species along the Florida
Reef Tract. Florida Department of Environmental Protection Available at: https://florida
Manzello DP (2015) Rapid recent warming of coral reefs in the Florida Keys. Sci Rep 5: 110. doi: 10.1038/srep16762
Maynard J, van Hooidonk R, Eakin MC, Puotinen M, Heron SF, Garren M, Lamb J, Williams G, Weil E, Willis B, Harvell CD (2015) Climate projections
of conditions that increase coral disease susceptibility and pathogen virulence. Nature Climate: doi:10.1038/nclimate2625.
Meyer JL, Castellanos-Gell J, Aeby G, Hase C, Ushijima B, Paul V (2019) Microbial community shifts associated with the ongoing stony coral tissue
loss outbreak on the Florida Reef Tract. Bio Rev. doi:
Miller J, Muller E, Rogers CS, Waara R, Atkinson A, Whelan KRT, Patterson M, Witcher B (2009) Coral disease following massive bleaching in 2005
causes 60% decline in coral cover on reefs in the US Virgin Islands. Coral Reefs 28: 92537
Miller MW, Karazsia J, Groves CE, Griffin S, Moore T, Wilber P, Gregg K (2016) Detecting sedimentation impacts to coral reefs resulting from
dredging the Port of Miami, Florida USA. PeerJ 4: e2711. doi: 10.7717/peerj. 2711
Precht, WF, Ginter B, Robbart ML, Fura R, van Woesik R (2016) Unprecedented disease-related coral mortality in Southeastern Florida. Sci Rep:
6. doi:10.1038/srep31374
Richardson L., Goldberg W, Carlton R, Halas J (1998). Coral disease outbreak in the Florida Keys: Plague Type II. Rev Biol Trop 46: 187198
Sunagawa S, DeSantis TZ, Piceno YM, Brodie EL, DeSalvo MK, Voolstra CR, Weil E, Andersen GL, Medina M (2009) Bacterial diversity and white
plague disease-associated community changes in the Caribbean coral Montastraea faveolata assessed by 16S rRNA microarray analysis and
clone library sequencing. The ISME journal 3: 1-12
Walton CJ, Hayes NK, Gilliam DS (2018) Impacts of a regional, multi-year, multi-species coral disease outbreak in southeast Florida. Front Mar
Sci 5: 323. doi: 10.3389/fmars.2018.00323
Weil E, Croquer A, Urreiztieta I (2009a) Temporal variability and consequences of coral diseases and bleaching in La Parguera, Puerto Rico from
20032007. Caribb J Sci 45:221246
Weil E, Cróquer A, Urreiztieta I (2009b) Yellow band disease compromises the reproductive output of the reef-building coral Montastraea
faveolata (Anthozoa, Scleractinia). Dis Aquat Org 87: 45-55
Weil E, Rogers CS (2011) Coral reef diseases in the Atlantic-Caribbean. In: Dubinsky Z, Stambler N, editors. Coral reefs: an ecosystem in transition.
Springer, pp 46591
Weil E, Rogers C, Croquer A (2017). Octocoral diseases in a changing sea. In Marine Animal Forests: The Ecology of Benthic Biodiversity Hotspots.
Rossi S, Gori A, Orejas Seco del Valle C (Editors). DOI: 10.1007/978-3-319-17001-5 Springer ISBN: 978-3-319-17001-5 (online).
Woodley CM, Downs CA, Bruckner AW, Porter J, Galloway SB, editors (2016) Diseases of coral. John Wiley & Sons, Hoboken, NJ
... The epizootic is notably known for the mass hard coral mortality (Willis et al. 2004). Environmental stressors such as rising seawater temperatures and nutrient pollution have been linked to WS outbreaks in the GBR (Bruno et al. 2007;Pollock et al. 2014) and other Indo-Pacific coral assemblages (Ruiz-Moreno et al. 2012;Couch et al. 2014;Aeby et al. 2016;Weil et al. 2019). ...
Marine biotechnology is any technique that uses marine breathing creatures (or their parts) to make or modify things, or to engineer marine microbes for particular purposes. The marine environment, comprised of oceans and seas, covers more than two-thirds of the biosphere’s exterior, which inhabit over 1,400,000 species and the most ancient forms of life. Marine microorganisms are of great significance because they have changed the global climate over time and control the atmosphere. Marine organisms adapt and survive in adverse environmental conditions, making them a huge reservoir for bioactive molecules with exceptional properties and high potential. Therefore, marine environments maintain an excess of a variety of bioactive molecules with distinctive characteristics and important capabilities for biotechnological purposes. Marine reservoirs are hotspots and provide a vital natural source of healthy food and functional food components with biological properties. The organisms’ diversity in the marine environment is unknown and needs to be investigated and utilized. Modern marine biotechnology has focused on intensifying research on aquatic organisms and their secondary metabolites. Marine biotechnologists are interested in many marine organisms like crustaceans, macro and microalgae, fish and fish by-products, fungi and bacteria for healthy as well as functional food ingredients, marine drugs, and energy. Biotechnological approaches have a crucial part in exploiting marine resources for food, functional food, biomedical purposes, and bioenergy.
... The epizootic is notably known for the mass hard coral mortality (Willis et al. 2004). Environmental stressors such as rising seawater temperatures and nutrient pollution have been linked to WS outbreaks in the GBR (Bruno et al. 2007;Pollock et al. 2014) and other Indo-Pacific coral assemblages (Ruiz-Moreno et al. 2012;Couch et al. 2014;Aeby et al. 2016;Weil et al. 2019). ...
One of the most underutilized biological resources in the world is the marine environment, which makes up nearly three-quarters of the Earth’s surface. A variety of organisms with unique biological systems and features can be found in the marine environment. They have evolved special characteristics that allow them to survive in a variety of hostile environments. By applying a wide variety of screening tools, extracts and purified compounds of these organisms can be studied for food processing, biological activities, and bioenergy production. Biomolecules derived from marine organisms have a wide range of applications in the food industry, including colorants, preservatives, and flavor enhancers. Some of the most useful marine-derived food ingredients are pigments, polyunsaturated fatty acids, sterols, polysaccharides, proteins, and enzymes. Among the therapeutics, more than 60 % of the active pharmaceutical formulations come from natural products or their derivatives, which have been reported to possess biological activities (anticancer, anti-inflammatory, antioxidant, antimicrobial, etc.). Using marine resources to produce biodiesel is one of the hottest areas for renewable energy. International cooperation, novel biotechnological tools, mass production of marine organisms, integration of biotechnology with other sectors, etc., will be necessary to fully explore the potential of marine sources.
... The epizootic is notably known for the mass hard coral mortality (Willis et al. 2004). Environmental stressors such as rising seawater temperatures and nutrient pollution have been linked to WS outbreaks in the GBR (Bruno et al. 2007;Pollock et al. 2014) and other Indo-Pacific coral assemblages (Ruiz-Moreno et al. 2012;Couch et al. 2014;Aeby et al. 2016;Weil et al. 2019). ...
Coral disease is one of the major threats affecting Caribbean reefs over the past four decades. In the Indo-Pacific, an increasing number of disease signs and syndromes have been documented at various reef localities, with white syndrome (WS) being the most common. Hence, most efforts are directed towards understanding the causal microbial pathogens using biotechnological applications. Based on preliminary coral surveys at selected reef sites around Tioman Island, Malaysia, six coral diseases and eight signs of compromised health were identified with the WS commonly found afflicting the Acropora and Montipora corals. In light of this, further examination was done to identify the potential of microbial pathogens from the apparently recorded WS coral disease using biochemical, molecular and histological methods. The data presented constitute baseline information on the status of coral disease that could be used by the relevant authorities to improve management and regulatory approaches in this marine-protected area.
... The epizootic is notably known for the mass hard coral mortality (Willis et al. 2004). Environmental stressors such as rising seawater temperatures and nutrient pollution have been linked to WS outbreaks in the GBR (Bruno et al. 2007;Pollock et al. 2014) and other Indo-Pacific coral assemblages (Ruiz-Moreno et al. 2012;Couch et al. 2014;Aeby et al. 2016;Weil et al. 2019). ...
The marine environment is a major source of biodiversity, food, energy and therapeutics. The vastness and significance of marine could be measured by the fact that about 90% of the marine environment is comprised of microbes and covers about 70% of the surface of planet Earth. Conditions like the wide range of temperature, pH, pressure and salinity further facilitate the diversification of marine organisms. Since the marine environment carries a wide range of organisms, therefore, this chapter is limited to marine bacteria only. We explained the therapeutic applications of different bacteria. Furthermore, to discover and harness the potential of marine microorganisms, we have proposed several methods and sophisticated tools that need to be developed for isolation, culturing and identification.
... El exceso de nutrientes, combinado con el incremento de temperatura también ha favorecido la proliferación de enfermedades blancas (consorcio de bacterias, SCTLD; Weil et al. 2019) y de blanqueamiento en las colonias de D. cylindrus (Bernal-Sotelo et al. 2019). La especie es altamente susceptible a la enfermedad de pérdida de tejido de coral duro (SCTLD; Weil et al. 2019), que fue reportada al inicio de 2022 en el archipiélago de San Andrés. ...
Full-text available
Anteriormente aceptada con el nombre Farfantepenaeus notialis, pero a partir del trabajo de Ma et al. (2011) quedó clara la monofilia del género Penaeus sensu lato, que incluye los géneros Penaeus, Fenneropenaeus, Litopenaeus y Farfantepenaeus.
... El exceso de nutrientes, combinado con el incremento de temperatura también ha favorecido la proliferación de enfermedades blancas (consorcio de bacterias, SCTLD; Weil et al. 2019) y de blanqueamiento en las colonias de D. cylindrus (Bernal-Sotelo et al. 2019). La especie es altamente susceptible a la enfermedad de pérdida de tejido de coral duro (SCTLD; Weil et al. 2019), que fue reportada al inicio de 2022 en el archipiélago de San Andrés. ...
Full-text available
Este libro presenta los resultados de la segunda evaluación del riesgo de extinción de invertebrados marinos en Colombia, un esfuerzo coordinado por INVEMAR y MINAMBIENTE, que involucró a 53 investigadores nacionales y contó con la asesoría del personal de la UICN.
... In some of the most heavily impacted regions of Florida, some coral species have experienced mortality exceeding 97% of their pre-outbreak populations (Precht et al., 2016). More recently, SCTLD outbreaks have also been observed in the Caribbean (Alvarez-Filip et al., 2019;Weil et al., 2019;Brandt et al., 2021;Dahlgren et al., 2021;Heres et al., 2021). ...
Full-text available
Since 2014, corals throughout Florida’s Coral Reef have been plagued by an epizootic of unknown etiology, colloquially termed stony coral tissue loss disease (SCTLD). Although in Florida the movement of this waterborne coral disease has been consistent with natural transport via water currents, outbreaks in the Caribbean have been more sporadic, with infections occurring in locations inconsistent with spread via natural means. Often Caribbean outbreaks have been clustered near ports, potentially implicating ships as mediators of SCTLD into new regions. Biofilms attached to ship hulls, ballast tank walls, or other surfaces could represent a possible vector for the disease. We investigated whether bacteria shed by healthy and SCTLD-diseased corals would form distinct biofilms, and whether a SCTLD signal would be detectable within biofilm bacterial communities. Stainless steel plates serving as proxies for ship hulls, ballast tank walls, and other colonizable surfaces were incubated for three days in filtered seawater mesocosms containing healthy or SCTLD-infected corals. Resulting biofilm bacterial communities were characterized through sequencing of the V4 region of the 16S rRNA gene. We determined that bacteria shed by healthy and diseased corals formed significantly different biofilms consisting of highly diverse taxa. Comparison with 16S data from previous SCTLD investigations spanning different coral species, collection locations, years, and source material revealed the presence of numerous genetically identical sequences within the biofilm bacterial communities formed during exposure to SCTLD-infected corals, including several previously identified as possible SCTLD bioindicators. These results suggest ship-associated biofilms may have the potential to be vectors for the transmission of SCTLD into new regions.
Effective treatment and prevention of any disease necessitates knowledge of the causative agent, yet the causative agents of most coral diseases remain unknown, in part due to the difficulty of distinguishing the pathogenic microbe(s) among the complex microbial backdrop of coral hosts. Stony coral tissue loss disease (SCTLD) is a particularly destructive disease of unknown etiology, capable of transmitting through the water column and killing entire colonies within a matter of weeks. Here we used a previously described method to (i) isolate diseased and apparently healthy coral colonies within individual mesocosms containing filtered seawater with low microbial background levels; (ii) incubate for several days to enrich the water with coral-shed microbes; (iii) use tangential-flow filtration to concentrate the microbial community in the mesocosm water; and then (iv) filter the resulting concentrate through a sequential series of different pore-sized filters. To investigate the size class of microorganism(s) associated with SCTLD transmission, we used 0.8 µm pore size filters to capture microeukaryotes and expelled zooxanthellae, 0.22 µm pore size filters to capture bacteria and large viruses, and 0.025 µm pore size filters to capture smaller viruses. In an attempt to further refine which size fraction(s) contained the transmissible element of SCTLD, we then applied these filters to healthy “receiver” coral fragments and monitored them for the onset of SCTLD signs over three separate experimental runs. However, several factors outside of our control confounded the transmission results, rendering them inconclusive. As the bulk of prior studies of SCTLD in coral tissues have primarily investigated the associated bacterial community, we chose to characterize the prokaryotic community associated with all mesocosm 0.22 µm pore size filters using Illumina sequencing of the V4 region of the 16S rRNA gene. We identified overlaps with prior SCTLD studies, including the presence of numerous previously identified SCTLD bioindicators within our mesocosms. The identification in our mesocosms of specific bacterial amplicon sequence variants that also appear across prior studies spanning different collection years, geographic regions, source material, and coral species, suggests that bacteria may play some role in the disease.
Full-text available
Coral disease prevalence has significantly increased under a changing climate, impacting coral community structure and functionality. The impacts and ecology of coral diseases are unclear in most high-latitude reefs. High-latitude locations are vulnerable to climate change; therefore, identifying diseases and developing region-specific baselines are important for local management. We report the first coral disease findings at UNESCO World Heritage Lord Howe Island Marine Park (31.5°S, 159°E), the southernmost coral reef system. Coral disease prevalence was recorded during November 2018, March and October 2019. Four coral diseases were identified from three reefs, white syndrome, skeletal eroding band, growth anomalies and endolithic hypermycosis impacting six coral taxa ( Acropora, Isopora , Monitpora, Pocillopora, Porites and Seriatopora ). Overall, disease prevalence was 5 ± 1%, and was highest in November (10 ± 1%) and significantly lower during March (5 ± 1%), coinciding with a bleaching event. White syndrome was the most prevalent disease (4 ± 1%) with 83 colonies of six taxa affected, predominately Isopora . Acroporids recorded the highest disease susceptibility, with three of the four diseases observed. Documenting baseline coral disease prevalence and monitoring throughout a bleaching event assists our understanding of disease ecology dynamics under current climate change impacts at high-latitude reefs.
Full-text available
An outbreak of stony coral tissue loss disease (SCTLD), emerged on reefs off the coast of southeast Florida in 2014 and continues to spread throughout Florida’s Reef Tract. SCTLD is causing extensive mortality of multiple coral species and disease signs vary among affected coral species with differences in rates of tissue loss (acute and subacute), lesion morphology (adjacent bleached zone or not) and lesion occurrence (focal and multi-focal). We examined the virulence, transmission dynamics and response to antibiotic treatment of coral species exhibiting different types of tissue loss lesions from two regions in Florida. Montastraea cavernosa with subacute tissue loss lesions in the southeast Florida region near Fort Lauderdale was compared to corals (multiple species) with acute tissue loss lesions in the Middle Keys. Corals from both regions showed progressive tissue loss but the in situ rate of mortality was significantly higher in tagged colonies in the Keys. Aquaria studies showed disease transmission occurred through direct contact and through the water column for corals from both regions. However, transmission success was higher for corals with acute vs. subacute lesions. There was 100% transmission for both test species, M. cavernosa and Meandrina meandrites, touching acute lesions. Among the three species touching subacute lesions, the disease transmitted readily to Orbicella faveolata (100%) followed by M. cavernosa (30%) with no transmission occurring with Porites astreoides. Diseased fragments of all species tested responded to antibiotic treatment with a cessation or slowing of the disease lesions suggesting that bacteria are involved in disease progression. Mortality was higher for in situ corals with acute lesions and transmission was higher in M. cavernosa exposed to acute lesions compared to subacute lesions, suggesting that different microbes may be involved with the two lesion types. However, since in situ mortality of M. cavernosa was not measured in the Middle Keys, we cannot completely rule out that a common pathogen is involved but is less virulent within M. cavernosa.
Full-text available
As many as 22 of the 45 coral species on the Florida Reef Tract are currently affected by stony coral tissue loss disease (SCTLD). The ongoing disease outbreak was first observed in 2014 in Southeast Florida near Miami and as of early 2019 has been documented from the northernmost reaches of the reef tract in Martin County down to Key West. We examined the microbiota associated with disease lesions and apparently healthy tissue on diseased colonies of Montastraea cavernosa , Orbicella faveolata , Diploria labyrinthiformis , and Dichocoenia stokesii . Analysis of differentially abundant taxa between disease lesions and apparently healthy tissue identified five unique amplicon sequence variants enriched in the diseased tissue in three of the coral species, namely an unclassified genus of Flavobacteriales and sequences identified as Fusibacter (Clostridiales), Planktotalea (Rhodobacterales), Algicola (Alteromonadales), and Vibrio (Vibrionales). In addition, several groups of likely opportunistic or saprophytic colonizers such as Epsilonbacteraeota, Patescibacteria, Clostridiales, Bacteroidetes, and Rhodobacterales were also enriched in SCTLD disease lesions. This work represents the first microbiological characterization of SCTLD, as an initial step toward identifying the potential pathogen(s) responsible for SCTLD.
Full-text available
Globally coral reefs have been declining at alarming rates as a result of anthropogenic stressors, leading to increased frequency and severity of widespread bleaching and disease events. These events are often associated with increased water temperatures due to climate change as well as regional and local stress from nutrient enrichment through runoff and sedimentation from coastal development. In late 2014, a white syndrome disease outbreak was reported off the coast of southeast Florida and was subsequently documented spreading throughout the region. This study examined the regional impacts of the disease event on the southeast Florida stony coral population utilizing stony coral demographic data from the Southeast Florida Coral Reef Evaluation and Monitoring Project (SECREMP). SECREMP is a long-term monitoring project examining 22 sites distributed from Miami-Dade County north to Martin County, Florida. The results revealed significant region-wide declines in stony coral diversity, density, and live tissue area corresponding with increased disease prevalence, which reached its maximum for the study period in 2016. Regional declines in coral density approached 30% loss and live tissue was upward of 60% as a result of the disease outbreak. Additionally, multiple species were severely impacted, especially the reef building, complexity-contributing species Montastraea cavernosa, Meandrina meandrites, and Siderastrea siderea. The disease outbreak resulted in acute mortality and altered the ecosystem function to a point such that recovery is uncertain. This multiyear, region-wide disease outbreak has been indiscriminate relative to coral species impacted and was arguably the most devastating disturbance event documented on the Southeast Florida Reef Tract.
Full-text available
The federal channel at Port of Miami, Florida, USA, was dredged between late 2013 and early 2015 to widen and deepen the channel. Due to the limited spatial extent of impact-assessment monitoring associated with the project, the extent of the dredging impacts on surrounding coral reefs has not been well quantified. Previously published remote sensing analyses, as well as agency and anecdotal reports suggest the most severe and largest area of sedimentation occurred on a coral reef feature referred to as the Inner Reef, particularly in the sector north of the channel. A confounding regional warm-water mass bleaching event followed by a coral disease outbreak during this same time frame made the assessment of dredging-related impacts to coral reefs adjacent to the federal channel difficult but still feasible. The current study sought to better understand the sedimentation impacts that occurred in the coral reef environment surrounding Port of Miami, to distinguish those impacts from other regional events or disturbances, and provide supplemental information on impact assessment that will inform discussions on compensatory mitigation requirements. To this end, in-water field assessments conducted after the completion of dredging and a time series analysis of tagged corals photographed pre-, during, and post-dredging, are used to discern dredging-related sedimentation impacts for the Inner Reef north. Results indicate increased sediment accumulation, severe in certain times and places, and an associated biological response (e.g., higher prevalence of partial mortality of corals) extended up to 700 m from the channel, whereas project-associated monitoring was limited to 50 m from the channel. These results can contribute to more realistic prediction of areas of indirect effect from dredging projects needed to accurately evaluate proposed projects and design appropriate compliance monitoring. Dredging projects near valuable and sensitive habitats subject to local and global stressors require monitoring methods capable of discerning non-dredging related impacts and adaptive management to ensure predicted and unpredicted project-related impacts are quantified. Anticipated increasing frequency and intensity of seasonal warming stress also suggests that manageable- but- unavoidable local stressors such as dredging should be partitioned from such seasonal thermal stress events.
Full-text available
Anomalously high water temperatures, associated with climate change, are increasing the global prevalence of coral bleaching, coral diseases, and coral-mortality events. Coral bleaching and disease outbreaks are often inter-related phenomena, since many coral diseases are a consequence of opportunistic pathogens that further compromise thermally stressed colonies. Yet, most coral diseases have low prevalence (<5%), and are not considered contagious. By contrast, we document the impact of an extremely high-prevalence outbreak (61%) of white-plague disease at 14 sites off southeastern Florida. White-plague disease was observed near Virginia Key, Florida, in September 2014, and after 12 months had spread 100 km north and 30 km south. The disease outbreak directly followed a high temperature coral-bleaching event and affected at least 13 coral species. Eusmilia fastigiata, Meandrina meandrites, and Dichocoenia stokesi were the most heavily impacted coral species, and were reduced to <3% of their initial population densities. A number of other coral species, including Colpophyllia natans, Pseudodiploria strigosa, Diploria labyrinthiformis, and Orbicella annularis were reduced to <25% of their initial densities. The high prevalence of disease, the number of susceptible species, and the high mortality of corals affected suggests this disease outbreak is arguably one of the most lethal ever recorded on a contemporary coral reef.
Full-text available
In recent decades, the cover of fleshy macroalgae has increased and coral cover has decreased on most Caribbean reefs. Coral mortality precipitated this transition, and the accumulation of macroalgal biomass has been enhanced by decreased herbivory and increased nutrient input. Populations of Acropora palmata (elkhorn coral) and A. cervicornis (staghorn coral), two of the most important framework-building species, have died throughout the Caribbean, substantially reducing coral cover and providing substratum for algal growth. Hurricanes have devastated local populations of Acropora spp. over the past 20–25 years, but white-band disease, a putative bacterial syndrome specific to the genus Acropora, has been a more significant source of mortality over large areas of the Caribbean region. Paleontological data suggest that the regional Acropora kill is without precedent in the late Holocene. In Belize, A. cervicornis was the primary ecological and geological constituent of reefs in the central shelf lagoon until the mid-1980s. After constructing reef framework for thousands of years, A. cervicornis was virtually eliminated from the area over a ten-year period. Evidence from other parts of the Caribbean supports the hypothesis of continuous Holocene accumulation and recent mass mortality of Acropora spp. Prospects are poor for the rapid recovery of A. cervicornis, because its reproductive strategy emphasizes asexual fragmentation at the expense of dispersive sexual reproduction. A. palmata also relies on fragmentation, but this species has a higher rate of sexual recruitment than A. cervicornis If the Acropora spp. do not recover, macroalgae will continue to dominate Caribbean reefs, accompanied by increased abundances of brooding corals, particularly Agaricia spp. and Porites spp. The outbreak of white-band disease has been coincident with increased human activity, and the possibility of a causal connection should be further investigated.
Full-text available
Rising sea temperatures are likely to increase the frequency of disease outbreaks affecting reef-building corals through impacts on coral hosts and pathogens. We present and compare climate model projections of temperature conditions that will increase coral susceptibility to disease, pathogen abundance and pathogen virulence. Both moderate (RCP 4.5) and fossil fuel aggressive (RCP 8.5) emissions scenarios are examined. We also compare projections for the onset of disease-conducive conditions and severe annual coral bleaching, and produce a disease risk summary that combines climate stress with stress caused by local human activities. There is great spatial variation in the projections, both among and within the major ocean basins, in conditions favouring disease development. Our results indicate that disease is as likely to cause coral mortality as bleaching in the coming decades. These projections identify priority locations to reduce stress caused by local human activities and test management interventions to reduce disease impacts.
Full-text available
Most coral reefs in the wider Caribbean have been showing alarming signs of decline in recent years. Coral diseases and bleaching were monitored seasonally from 2003 to 2007 using the modified CARICOMP protocol with a stratified design to assess spatial and temporal variability in community level coral disease prevalence (proportion of affected colonies) at six reefs along an inshore-offshore gradient in La Parguera, southwest coast of Puerto Rico. Temperature loggers were deployed in each reef to assess co-variation between disease prevalence and virulence, and temperature. Virulence was assessed in Montastraea faveolata by tagging colonies, marking diseased edges, photographing and following them through time. Overall, all major reef-building species and other common reef groups were variously affected by disease and bleaching. Eleven diseases affected up to 42 species of scleractinian corals, 5 octocorals, 2 hydrocorals, 3 zoanthids, 2 sponges and 2 crustose coralline algae. Bleaching affected 52 species of corals, 22 octocorals, 3 hydrocorals, 2 zoanthids and 3 sponges. The prevalence of the diseases compromised coral health and varied significantly between seasons within years as well as among reefs within years and across years for each reef. White plague, yellow band and bleaching were the most prevalent and damaging diseases. Three white plague, two yellow band outbreaks and three bleaching events of different intensities were observed during the five years of study. Yellow band disease increased in prevalence (from 4 % to 30%) and virulence (0.8 ± 0.2 to 3.9 ± 1.4 cm/month) over 6 years, becoming one of the most important agents of coral mortality. Higher disease prevalence was consistently found at the mid-shelf and shelf-edge reefs than in reefs closest to the shoreline. The combination of white plague disease outbreaks, the intensive bleaching of 2005 and the chronic yellow band caused an average 53 % of live coral tissue loss in four years, the highest coral mortalities ever recorded in southwest Puerto Rico.
In 1983-1984, the sea urchin Diadema antillarum suffered mass mortality throughout the Caribbean, Florida, and Bermuda. The demise of this herbivore contributed to a phase shift of Caribbean reefs from coral-dominated to alga-dominated communities. A compilation of published data of D. antillarum population densities shows that there has been moderate recovery since 1983, with the highest rates on islands of the eastern Caribbean. On the average the current population densities are approximately 12% of those before the die-off, apparently because of recruitment limitation, but the exact factors that are constraining the recovery are unclear. Scattered D. antillarum cohorts in some localities and aggregation of settled individuals in shallow water have created zones of higher herbivory in which juvenile coral recruitment, survivorship, and growth are higher than they are in alga-dominated areas. Unlike other stressors on Caribbean coral reefs, recent changes in D. antillarumd populations progress toward aiding the recovery of coral cover. Expected final online publication date for the Annual Review of Marine Science Volume 8 is January 03, 2016. Please see for revised estimates.