scholarly journals Multi-Variate Analyses of Coral Mortality From the 2014–2015 Stony Coral Tissue Loss Disease Outbreak Off Miami-Dade County, Florida

2021 ◽  
Vol 8 ◽  
Author(s):  
Rachele Spadafore ◽  
Ryan Fura ◽  
William F. Precht ◽  
Steven V. Vollmer

Environmental compliance monitoring associated with the Port Miami dredging project (2013–2015), designed to assess the impact of project-generated sediments on the local coral community, fortuitously captured a thermal bleaching event and the first reports of an emergent, highly contagious, white-plague-like coral disease outbreak in the fall of 2014. The disease, now termed stony coral tissue loss disease (SCTLD), has decimated reefs throughout Florida and is now spreading across the Caribbean. The high prevalence of disease, the number of affected species, and the high mortality of corals affected suggests SCTLD may be the most lethal coral disease ever recorded. Previous analyses of the dredge monitoring data have reached mixed conclusions about the relative impact of dredging on coral mortality and has often parsed out disease susceptible individuals to isolate the impacts of dredging only. We use multi-variate analyses, including time-based survival analyses, to examine the timing and impacts of dredging, coral bleaching, and disease on local coral mortality. By examining the status of corals monthly from the October 2013 to July 2015 observational period, we found that coral mortality was not significantly affected by a coral’s proximity to the dredge site or sediment burial. Instead, coral mortality was most strongly impacted by disease and the emergence of SCTLD during the monitoring period. During the 2-year monitoring period, 26.3% of the monitored corals died, but the only conditions significantly affected by the dredge were partial burial and partial mortality. The strongest link to mortality was due to disease, which impacted coral species differently depending on their susceptibility to SCTLD. The focus on disturbances associated with dredging created a circumstance where the greater impacts of this emergent disease were downplayed, leading to a false narrative of the resulting mortality on the local coral communities. The results of this study reveal that while local events such as a dredging project do have quantifiable effects and can be harmful to corals, regional and global threats that result in mass coral mortality such as thermal stress and disease represent an existential threat to coral reefs and must be urgently addressed.

2021 ◽  
Vol 8 ◽  
Author(s):  
Graham Kolodziej ◽  
Michael S. Studivan ◽  
Arthur C. R. Gleason ◽  
Chris Langdon ◽  
Ian C. Enochs ◽  
...  

Since the appearance of stony coral tissue loss disease (SCTLD) on reefs off Miami in 2014, this unprecedented outbreak has spread across the entirety of Florida’s coral reef tract, as well as to many territories throughout the Caribbean. The endemic zone reached the upper Florida Keys by 2016, resulting in partial or complete mortality of coral colonies across numerous species. Disease was first observed at Cheeca Rocks (Islamorada, Florida) in the beginning of 2018, with reports of coral mortality peaking mid-year. The disease was still present at Cheeca Rocks as of March 2020, however, to a lesser degree compared to the initial outbreak. Annual monitoring efforts have been ongoing at Cheeca Rocks since 2012, including repeated benthic photomosaics of a 330 m2 survey zone, spanning six replicate sites. As such, a repository of coral community composition data exists for before and after the disease outbreak that was analyzed to assess the impacts of SCTLD on reef communities at an upper Florida Keys inshore reef. Cheeca Rocks is hypothesized to be a resilient reef due to its persistent high coral cover despite its inshore location, which subjects corals to fluctuating water quality and marginal environmental conditions. Coral populations here have been shown to recover from bleaching events and heat stress with minimal coral mortality. Though colonies of coral species characterized as highly and moderately susceptible to SCTLD (e.g., Colpophyllia natans, Diploria labyrinthiformis, Pseudodiploria strigosa, Orbicella annularis, and O. faveolata) suffered mortality as a result of the outbreak with an average loss of 16.42% relative cover by species, the overall impacts on coral cover and community structure were relatively low, contributing to a loss of total coral cover of only 1.65%. Comparison of photomosaic data to other studies indicate Cheeca Rocks may not have been affected as severely as other sites on Florida’s coral reef tract, underlying this site’s potential role in coral resilience to stressors including bleaching events, land-based pollution, and disease epizootics.


Author(s):  
Lorenzo Alvarez-Filip ◽  
Nuria Estrada-Saldívar ◽  
Esmeralda Pérez-Cervantes ◽  
Ana Molina-Hernández ◽  
Francisco J. Gonzalez-Barrios

Caribbean reef corals have experienced unprecedented declines from climate change, anthropogenic stressors and infectious diseases in recent decades. Since 2014 a highly lethal, new disease, called stony coral tissue loss disease (SCTLD), has impacted many species in Florida. During the summer of 2018 we noticed an anomalously high disease prevalence affecting different coral species in the northern portion of the Mexican Caribbean. We assessed the severity of this outbreak in 2018/2019 using the AGRRA coral protocol to survey 82 reef sites across the Mexican Caribbean. Then, using a subset of 14 sites we detailed information from before the outbreak (2016/2017) to explore the consequences of the disease on the condition and composition of coral communities. Our findings show that the disease outbreak has already spread across the entire region, affecting similar species (with similar disease patterns) to those previously described for Florida. However, we observed a great variability in prevalence and tissue mortality that was not attributable to any geographical gradient. Using long-term data, we determined that there is no evidence of such high coral disease prevalence anywhere in the region before 2018, which suggests that the entire Mexican Caribbean (~450 km) was afflicted by the disease within a few months. The analysis of sites that contained pre-outbreak information showed that this event considerably increased coral mortality and severely changed the structure of coral communities in the region. Given the high prevalence and lethality of this disease, and the high number of susceptible species, we encourage reef researchers, managers and stakeholders across the Western Atlantic to accord it the highest priority for the near future.


2019 ◽  
Author(s):  
Lorenzo Alvarez-Filip ◽  
Nuria Estrada-Saldívar ◽  
Esmeralda Pérez-Cervantes ◽  
Ana Molina-Hernández ◽  
Francisco J. Gonzalez-Barrios

Caribbean reef corals have experienced unprecedented declines from climate change, anthropogenic stressors and infectious diseases in recent decades. Since 2014 a highly lethal, new disease, called stony coral tissue loss disease (SCTLD), has impacted many species in Florida. During the summer of 2018 we noticed an anomalously high disease prevalence affecting different coral species in the northern portion of the Mexican Caribbean. We assessed the severity of this outbreak in 2018/2019 using the AGRRA coral protocol to survey 82 reef sites across the Mexican Caribbean. Then, using a subset of 14 sites we detailed information from before the outbreak (2016/2017) to explore the consequences of the disease on the condition and composition of coral communities. Our findings show that the disease outbreak has already spread across the entire region, affecting similar species (with similar disease patterns) to those previously described for Florida. However, we observed a great variability in prevalence and tissue mortality that was not attributable to any geographical gradient. Using long-term data, we determined that there is no evidence of such high coral disease prevalence anywhere in the region before 2018, which suggests that the entire Mexican Caribbean (~450 km) was afflicted by the disease within a few months. The analysis of sites that contained pre-outbreak information showed that this event considerably increased coral mortality and severely changed the structure of coral communities in the region. Given the high prevalence and lethality of this disease, and the high number of susceptible species, we encourage reef researchers, managers and stakeholders across the Western Atlantic to accord it the highest priority for the near future.


Coral Reefs ◽  
2020 ◽  
Vol 39 (4) ◽  
pp. 861-866 ◽  
Author(s):  
Nuria Estrada-Saldívar ◽  
Ana Molina-Hernández ◽  
Esmeralda Pérez-Cervantes ◽  
Francisco Medellín-Maldonado ◽  
F. Javier González-Barrios ◽  
...  

2021 ◽  
Author(s):  
Cynthia C. Becker ◽  
Marilyn Brandt ◽  
Carolyn A. Miller ◽  
Amy Apprill

AbstractStony Coral Tissue Loss Disease (SCTLD) is a devastating disease. Since 2014, it has spread along the entire Florida Reef Tract, presumably via a water-borne vector, and into the greater Caribbean. It was first detected in the United States Virgin Islands (USVI) in January 2019. To more quickly identify disease biomarker microbes, we developed a rapid pipeline for microbiome sequencing. Over a span of 10 days we collected, processed, and sequenced coral tissue and near-coral seawater microbiomes from diseased and apparently healthy Colpophyllia natans, Montastraea cavernosa, Meandrina meandrites and Orbicella franksi. Analysis of the resulting bacterial and archaeal 16S ribosomal RNA sequences revealed 25 biomarker amplicon sequence variants (ASVs) enriched in diseased tissue. These biomarker ASVs were additionally recovered in near-coral seawater (within 5 cm of coral surface), a potential recruitment zone for pathogens. Phylogenetic analysis of the biomarker ASVs belonging to Vibrio, Arcobacter, Rhizobiaceae, and Rhodobacteraceae revealed relatedness to other coral disease-associated bacteria and lineages novel to corals. Additionally, four ASVs (Algicola, Cohaesibacter, Thalassobius and Vibrio) were exact sequence matches to microbes previously associated with SCTLD. This work represents the first rapid coral disease sequencing effort and identifies biomarkers of SCTLD that could be targets for future SCTLD research.


2020 ◽  
Vol 7 ◽  
Author(s):  
Thomas Dobbelaere ◽  
Erinn M. Muller ◽  
Lewis J. Gramer ◽  
Daniel M. Holstein ◽  
Emmanuel Hanert

For the last six years, the Florida Reef Tract (FRT) has been experiencing an outbreak of the Stony Coral Tissue Loss Disease (SCTLD). First reported off the coast of Miami-Dade County in 2014, the SCTLD has since spread throughout the entire FRT with the exception of the Dry Tortugas. However, the causative agent for this outbreak is currently unknown. Here we show how a high-resolution bio-physical model coupled with a modified patch Susceptible-Infectious-Removed epidemic model can characterize the potential causative agent(s) of the disease and its vector. In the present study, the agent is assumed to be transported within composite material (e.g., coral mucus, dying tissues, and/or resuspended sediments) driven by currents and potentially persisting in the water column for extended periods of time. In this framework, our simulations suggest that the SCTLD is likely to be propagated within neutrally buoyant material driven by mean barotropic currents. Calibration of our model parameters with field data shows that corals are diseased within a mean transmission time of 6.45 days, with a basic reproduction number slightly above 1. Furthermore, the propagation speed of the disease through the FRT is shown to occur for a well-defined range of values of a disease threshold, defined as the fraction of diseased corals that causes an exponential growth of the disease in the reef site. Our results present a new connectivity-based approach to understand the spread of the SCTLD through the FRT. Such a method can provide a valuable complement to field observations and lab experiments to support the management of the epidemic as well as the identification of its causative agent.


Coral Reefs ◽  
2020 ◽  
Vol 39 (6) ◽  
pp. 1581-1590
Author(s):  
Kara R. Noonan ◽  
Michael J. Childress

AbstractSince 2014, stony coral tissue loss disease (SCTLD) has rapidly spread throughout the Florida reef tract infecting and killing dozens of coral species. Previous studies have found that corallivorous fishes, such as butterflyfishes, are positively correlated with coral disease prevalence at both local and regional scales. This study investigates the association of SCTLD infection and butterflyfish abundance and behaviors on ten reefs in the middle Florida Keys. Divers conducted video surveys of reef fish abundance and disease prevalence in June 2017, 2018, and 2019; before, during, and after the outbreak of SCTLD infections. SCTLD prevalence increased from 3.2% in 2017 to 36.9% in 2018 and back to 2.7% in 2019. Butterflyfish abundances also showed a similar pattern with a twofold increase in abundance in 2018 over abundances in 2017 and 2019. To better understand the association of individual species of butterflyfishes and diseased corals, 60 coral colonies (20 healthy, 20 diseased, 20 recently dead) were tagged and monitored for butterflyfish activity using both diver-based AGGRA fish counts and 1-h time-lapse videophotography collected in the summers of 2018 and 2019. All reef fishes were more abundant on corals with larger surface areas of live tissue, but only the foureye butterflyfish preferred corals with larger surface areas of diseased tissues. Estimates of association indicate that foureye butterflyfish were found significantly more on diseased corals than either healthy or recently dead corals when compared with the other species of butterflyfishes. Foureye butterflyfish were observed to feed directly on the SCTLD line of infection, while other butterflyfish were not. Furthermore, association of foureye butterflyfish with particular diseased corals decreased from 2018 to 2019 as the SCTLD infections disappeared. Our findings suggest that foureye butterflyfish recruit to and feed on SCTLD-infected corals which may influence the progression and/or transmission of this insidious coral disease.


2019 ◽  
Author(s):  
William F Precht

A coral disease with white plague-like signs was observed near Virginia Key, Florida, in September 2014. The disease outbreak directly followed a regional high temperature coral-bleaching event. Now called stony coral tissue loss disease (SCTLD), it has spread the length of the Florida Reef Tract from Key West to Martin County, a distance of about 450 km. Recently, the disease has also been observed at a number of sites throughout the Caribbean. The high prevalence of disease, the number of susceptible species, and the high mortality of corals affected suggests this outbreak is arguably one of the most lethal ever recorded. The initial response to this catastrophic disease by resource mangers with purview over the ecosystem was slow. There is generally a very short window of opportunity to intervene in disease amelioration or eradication in the marine environment. This slow response enabled the disease to spread unchecked. Why was the response to the loss of our coral reefs to a coral disease epidemic, such a massive failure? This includes our failure as scientists, regulators, resource managers, the local media, and policy makers alike. This review encapsulates the numerous reasons for our failures during the first few years of the outbreak. Specifically, I show how the Port Miami dredging project that was ongoing at the time of the initial outbreak created a distraction as local NGO's, regulatory agencies, and resource managers initially blamed the project for observed large-scale coral losses. However, detailed analysis of 650 tagged corals that were part of a repeated measures monitoring program required for permit compliance associated with the Port Miami dredge project reveal that both disease susceptibility and coral mortality are invariant with the results collected by a number of scientific teams throughout the region. Finally, when the agencies responded to the outbreak the effort it was too little and much too late to make a meaningful difference. Because of the languid management response to this outbreak, we are now sadly faced with a situation where much of our management efforts are focused on the rescue of genetic material from coral species now at risk of regional extinction.


2022 ◽  
Vol 8 ◽  
Author(s):  
Michael S. Studivan ◽  
Ashley M. Rossin ◽  
Ewelina Rubin ◽  
Nash Soderberg ◽  
Daniel M. Holstein ◽  
...  

Stony coral tissue loss disease (SCTLD) was first observed in 2014 near Virginia Key in Miami-Dade County, Florida. Field sampling, lab experiments, and modeling approaches have suggested that reef sediments may play a role in SCTLD transmission, though a positive link has not been tested experimentally. We conducted an ex situ transmission assay using a statistically-independent disease apparatus to test whether reef sediments can transmit SCTLD in the absence of direct contact between diseased and healthy coral tissue. We evaluated two methods of sediment inoculation: batch inoculation of sediments collected from southeast Florida using whole colonies of diseased Montastraea cavernosa, and individual inoculations of sediments following independent, secondary infections of ∼5 cm2 coral fragments. Healthy fragments of the coral species Orbicella faveolata and M. cavernosa were exposed to these diseased sediment treatments, as well as direct disease contact and healthy sediment controls. SCTLD transmission was observed for both batch and individual diseased sediment inoculation treatments, albeit with lower proportions of infected individuals as compared to disease contact controls. The time to onset of lesions was significantly different between species and among disease treatments, with the most striking infections occurring in the individual diseased sediment treatment in under 24 h. Following infection, tissue samples were confirmed for the presence of SCTLD signs via histological examination, and sediment subsamples were analyzed for microbial community variation between treatments, identifying 16 SCTLD indicator taxa in sediments associated with corals experiencing tissue loss. This study demonstrated that reef sediments can indeed transmit SCTLD through indirect exposure between diseased and healthy corals, and adds credence to the assertion that SCTLD transmission occurs via an infectious agent or agents. This study emphasizes the critical need to understand the roles that sediment microbial communities and coastal development activities may have on the persistence of SCTLD throughout the endemic zone, especially in the context of management and conservation strategies in Florida and the wider Caribbean.


2019 ◽  
Author(s):  
Julie L. Meyer ◽  
Jessy Castellanos-Gell ◽  
Greta S. Aeby ◽  
Claudia Häse ◽  
Blake Ushijima ◽  
...  

ABSTRACTAs 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.


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