scholarly journals Genotypic variation in disease susceptibility among cultured stocks of elkhorn and staghorn corals

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6751 ◽  
Author(s):  
Margaret W. Miller ◽  
Philip J. Colburn ◽  
Emma Pontes ◽  
Dana E. Williams ◽  
Allan J. Bright ◽  
...  
Keyword(s):  
Disease Susceptibility ◽  
Coral Disease ◽  
Genotypic Variation ◽  
Genetic Resistance ◽  
Field Tests ◽  
Florida Keys ◽  
Tissue Loss ◽  
Acropora Palmata ◽  
Population Declines ◽  
Primary Driver

Disease mortality has been a primary driver of population declines and the threatened status of the foundational Caribbean corals, Acropora palmata and A. cervicornis. There remain few tools to effectively manage coral disease. Substantial investment is flowing into in situ culture and population enhancement efforts, while disease takes a variable but sometimes high toll in restored populations. If genetic resistance to disease can be identified in these corals, it may be leveraged to improve resistance in restored populations and possibly lead to effective diagnostic tests and disease treatments. Using a standardized field protocol based on replicated direct-graft challenge assays, we quantified this important trait in cultured stocks from three field nurseries in the Florida Keys. Field tests of 12 genotypes of A. palmata and 31 genotypes of A. cervicornis revealed significant genotypic variation in disease susceptibility of both species measured both as risk of transmission (percent of exposed fragments that displayed tissue loss) and as the rate of tissue loss (cm2 d–1) in fragments with elicited lesions. These assay results provide a measure of relative disease resistance that can be incorporated, along with consideration of other important traits such as growth and reproductive success, into restoration strategies to yield more resilient populations.

scholarly journals Systematic Analysis of White Pox Disease in Acropora palmata of the Florida Keys and Role of Serratia marcescens

2015 ◽  
Vol 81 (13) ◽  
pp. 4451-4457 ◽  
Author(s):  
Jessica L. Joyner ◽  
Kathryn P. Sutherland ◽  
Dustin W. Kemp ◽  
Brett Berry ◽  
Ashton Griffin ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Coral Disease ◽  
Florida Keys ◽  
Disease Status ◽  
Acropora Palmata ◽  
Overlying Water ◽  
Systematic Analysis ◽  
Content Type ◽  
Apparently Healthy

ABSTRACTWhite pox disease (WPD) affects the threatened elkhorn coral,Acropora palmata. Owing in part to the lack of a rapid and simple diagnostic test, there have been few systematic assessments of the prevalence of acroporid serratiosis (caused specifically bySerratia marcescens) versus general WPD signs. Six reefs in the Florida Keys were surveyed between 2011 and 2013 to determine the disease status ofA. palmataand the prevalence ofS. marcescens. WPD was noted at four of the six reefs, with WPD lesions found on 8 to 40% of the colonies surveyed.S. marcescenswas detected in 26.9% (7/26) of the WPD lesions and in mucus from apparently healthy colonies both during and outside of disease events (9%; 18/201).S. marcescenswas detected with greater frequency inA. palmatathan in the overlying water column, regardless of disease status (P= 0.0177).S. marcescenscould not be cultured fromA. palmatabut was isolated from healthy colonies of other coral species and was identified as pathogenic pulsed-field gel electrophoresis type PDR60. WPD lesions were frequently observed on the reef, but unlike in prior outbreaks, no whole-colony death was observed. PathogenicS. marcescenswas circulating on the reef but did not appear to be the primary pathogen in these recent WPD episodes, suggesting that other pathogens or stressors may contribute to signs of WPD. Results highlight the critical importance of diagnostics in coral disease investigations, especially given that field manifestation of disease may be similar, regardless of the etiological agent.

scholarly journals Association of butterflyfishes and stony coral tissue loss disease in the Florida Keys

Coral Reefs ◽  
2020 ◽  
Vol 39 (6) ◽  
pp. 1581-1590
Author(s):  
Kara R. Noonan ◽  
Michael J. Childress
Keyword(s):  
Coral Disease ◽  
Florida Keys ◽  
Time Lapse ◽  
Reef Fishes ◽  
Disease Prevalence ◽  
Tissue Loss ◽  
Coral Tissue ◽  
Individual Species ◽  
Stony Coral ◽  
Surface Areas

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.

scholarly journals Removal of corallivorous snails as a proactive conservation tool

2014 ◽  
Author(s):  
Dana E Williams ◽  
Margaret W Miller ◽  
Allan J Bright ◽  
Caitlin M Cameron
Keyword(s):  
Impact Analysis ◽  
Florida Keys ◽  
Tissue Loss ◽  
Common Source ◽  
Acropora Palmata ◽  
Partial Mortality ◽  
Host Coral ◽  
Coralliophila Abbreviata ◽  
Term Monitoring

Corallivorous snail feeding is a common source of tissue loss for the threatened coral Acropora palmata, accounting for roughly one-quarter of tissue loss in monitored study plots over seven years. However, corallivory by Coralliophila abbreviata is one of the few major sources of partial mortality (contrasting with threats such as bleaching, disease, or storm disturbances) that may be locally managed. We conducted a field experiment to explore the effectiveness and feasibility of snail removal. Long-term monitoring plots on six reefs in the upper Florida Keys were assigned to one of three removal treatments: 1) removal from A. palmata only, 2) removal from all host coral species, or 3) no-removal controls. During the initial removal in June 2011, 639 snails were removed from twelve 150 m2 plots. Snails were removed two additional times during a seven month “removal phase”, then counted at five surveys over the next 19 months to track recolonization. At the conclusion, snails were collected, measured, and sexed. Before-After-Control-Impact analysis revealed that both snail abundance and feeding scar prevalence were reduced in removal treatments compared to the control, but there was no difference between removal treatments. Recolonization by snails to baseline abundance is estimated to be 4.3 years and did not differ between removal treatments. Recolonization rate was significantly correlated with baseline snail abundance. Maximum snail size decreased from 47.0 mm to 34.6 mm in the removal treatments. The effort required to remove snails from A. palmata was 30 diver minutes per 150 m2 plot, compared with 51 minutes to remove snails from all host corals. Since there was no additional benefit observed with removing snails from all host species, removals can be more efficiently focused on only A. palmata colonies, and in areas where C. abbreviata abundance is high, to effectively conserve A. palmata in targeted areas.

scholarly journals Removal of corallivorous snails as a proactive conservation tool

2014 ◽  
Author(s):  
Dana E Williams ◽  
Margaret W Miller ◽  
Allan J Bright ◽  
Caitlin M Cameron
Keyword(s):  
Impact Analysis ◽  
Florida Keys ◽  
Tissue Loss ◽  
Common Source ◽  
Acropora Palmata ◽  
Partial Mortality ◽  
Host Coral ◽  
Coralliophila Abbreviata ◽  
Term Monitoring

Corallivorous snail feeding is a common source of tissue loss for the threatened coral Acropora palmata, accounting for roughly one-quarter of tissue loss in monitored study plots over seven years. However, corallivory by Coralliophila abbreviata is one of the few major sources of partial mortality (contrasting with threats such as bleaching, disease, or storm disturbances) that may be locally managed. We conducted a field experiment to explore the effectiveness and feasibility of snail removal. Long-term monitoring plots on six reefs in the upper Florida Keys were assigned to one of three removal treatments: 1) removal from A. palmata only, 2) removal from all host coral species, or 3) no-removal controls. During the initial removal in June 2011, 639 snails were removed from twelve 150 m2 plots. Snails were removed two additional times during a seven month “removal phase”, then counted at five surveys over the next 19 months to track recolonization. At the conclusion, snails were collected, measured, and sexed. Before-After-Control-Impact analysis revealed that both snail abundance and feeding scar prevalence were reduced in removal treatments compared to the control, but there was no difference between removal treatments. Recolonization by snails to baseline abundance is estimated to be 4.3 years and did not differ between removal treatments. Recolonization rate was significantly correlated with baseline snail abundance. Maximum snail size decreased from 47.0 mm to 34.6 mm in the removal treatments. The effort required to remove snails from A. palmata was 30 diver minutes per 150 m2 plot, compared with 51 minutes to remove snails from all host corals. Since there was no additional benefit observed with removing snails from all host species, removals can be more efficiently focused on only A. palmata colonies, and in areas where C. abbreviata abundance is high, to effectively conserve A. palmata in targeted areas.

scholarly journals Shifting white pox aetiologies affecting Acropora palmata in the Florida Keys, 1994–2014

2016 ◽  
Vol 371 (1689) ◽  
pp. 20150205 ◽  
Author(s):  
Kathryn P. Sutherland ◽  
Brett Berry ◽  
Andrew Park ◽  
Dustin W. Kemp ◽  
Keri M. Kemp ◽  
...  
Keyword(s):  
Coral Disease ◽  
Bacterial Pathogen ◽  
Florida Keys ◽  
Disease State ◽  
Moving Target ◽  
Acropora Palmata ◽  
Coral Diseases ◽  
Disease Aetiology ◽  
The Caribbean

We propose ‘the moving target hypothesis’ to describe the aetiology of a contemporary coral disease that differs from that of its historical disease state. Hitting the target with coral disease aetiology is a complex pursuit that requires understanding of host and environment, and may lack a single pathogen solution. White pox disease (WPX) affects the Caribbean coral Acropora palmata . Acroporid serratiosis is a form of WPX for which the bacterial pathogen ( Serratia marcescens ) has been established. We used long-term (1994–2014) photographic monitoring to evaluate historical and contemporary epizootiology and aetiology of WPX affecting A. palmata at eight reefs in the Florida Keys. Ranges of WPX prevalence over time (0–71.4%) were comparable for the duration of the 20-year study. Whole colony mortality and disease severity were high in historical (1994–2004), and low in contemporary (2008–2014), outbreaks of WPX. Acroporid serratiosis was diagnosed for some historical (1999, 2003) and contemporary (2012, 2013) outbreaks, but this form of WPX was not confirmed for all WPX cases. Our results serve as a context for considering aetiology as a moving target for WPX and other coral diseases for which pathogens are established and/or candidate pathogens are identified. Coral aetiology investigations completed to date suggest that changes in pathogen, host and/or environment alter the disease state and complicate diagnosis.

scholarly journals Abundance and Multilocus Sequence Analysis of Vibrio Bacteria Associated with Diseased Elkhorn Coral (Acropora palmata) of the Florida Keys

2017 ◽  
Vol 84 (2) ◽  
Author(s):  
Keri M. Kemp ◽  
Jason R. Westrich ◽  
Magdy S. Alabady ◽  
Martinique L. Edwards ◽  
Erin K. Lipp
Keyword(s):  
Sequence Analysis ◽  
Hot Spot ◽  
Florida Keys ◽  
Etiologic Agent ◽  
Tissue Loss ◽  
Multilocus Sequence Analysis ◽  
Acropora Palmata ◽  
Content Type ◽  
Temporal Sampling ◽  
Apparently Healthy

ABSTRACT The critically endangered elkhorn coral (Acropora palmata) is affected by white pox disease (WPX) throughout the Florida Reef Tract and wider Caribbean. The bacterium Serratia marcescens was previously identified as one etiologic agent of WPX but is no longer consistently detected in contemporary outbreaks. It is now believed that multiple etiologic agents cause WPX; however, to date, no other potential pathogens have been thoroughly investigated. This study examined the association of Vibrio bacteria with WPX occurrence from August 2012 to 2014 at Looe Key Reef in the Florida Keys, USA. The concentration of cultivable Vibrio was consistently greater in WPX samples than in healthy samples. The abundance of Vibrio bacteria relative to total bacteria was four times higher in samples from WPX lesions than in adjacent apparently healthy regions of diseased corals based on quantitative PCR (qPCR). Multilocus sequence analysis (MLSA) was used to assess the diversity of 69 Vibrio isolates collected from diseased and apparently healthy A. palmata colonies and the surrounding seawater. Vibrio species with known pathogenicity to corals were detected in both apparently healthy and diseased samples. While the causative agent(s) of contemporary WPX outbreaks remains elusive, our results suggest that Vibrio spp. may be part of a nonspecific heterotrophic bacterial bloom rather than acting as primary pathogens. This study highlights the need for highly resolved temporal sampling in situ to further elucidate the role of Vibrio during WPX onset and progression. IMPORTANCE Coral diseases are increasing worldwide and are now considered a major contributor to coral reef decline. In particular, the Caribbean has been noted as a coral disease hot spot, owing to the dramatic loss of framework-building acroporid corals due to tissue loss diseases. The pathogenesis of contemporary white pox disease (WPX) outbreaks in Acropora palmata remains poorly understood. This study investigates the association of Vibrio bacteria with WPX.

scholarly journals Education and Research: A Symbiosis to Better Understand a Novel Coral Disease

2021 ◽  
Vol 8 ◽  
Author(s):  
Deanna M. Soper
Keyword(s):  
Undergraduate Students ◽  
Coral Disease ◽  
Florida Keys ◽  
Emerging Diseases ◽  
Research Field ◽  
Tissue Loss ◽  
Coral Tissue ◽  
Rapid Progression ◽  
Geographic Scale ◽  
Reef Tract

Ongoing ecological events, such as new and emerging diseases, provide an important platform for education and research. Field courses and undergraduate research projects can be critical to assisting students with learning scientific skills and career discernment as these experiences provide more one-on-one instruction and an immersive learning environment. A novel coral disease called “Stony Coral Tissue Loss Disease” (SCTLD) provided one such opportunity. SCTLD is characterized by rapid progression with entire coral heads dying within 2–3 weeks after initial observation of the onset of symptoms. At a wider geographic scale, the disease has migrated with extreme velocity and has now been documented across the Caribbean from as far North as the Southeast Florida Reef Tract, as far South as St. Lucia, and as far West as Honduras and Belize. Here, I summarize what is currently known about SCTLD and document an educational field course that involved eight undergraduate students with visits to multiple locations along the Florida Keys Reef Tract during the disease progression in March 2019. Students were able to observe sites where SCTLD had been present for over 2 years and sites where the disease was only just emerging for observational comparison. Student educational outcomes from field trips and activities will be discussed. Current research and educational activities can interact to enhance each other, creating a positive feedback loop. Future directions for research, educational opportunities, and their interaction to accelerate understanding of this novel disease are discussed.

scholarly journals Reestablishing a stepping-stone population of the threatened elkhorn coral Acropora palmata to aid regional recovery

2020 ◽  
Vol 43 ◽  
pp. 461-473
Author(s):  
IB Kuffner ◽  
A Stathakopoulos ◽  
LT Toth ◽  
LA Bartlett
Keyword(s):  
Local Adaptation ◽  
Genetic Effect ◽  
Florida Keys ◽  
Gauge Potential ◽  
Acropora Palmata ◽  
Assisted Migration ◽  
Western Atlantic ◽  
Genetic Strains ◽  
Entire Experiment ◽  
Migration Experiment

Recovery of the elkhorn coral Acropora palmata is critical to reversing coral reef ecosystem collapse in the western Atlantic, but the species is severely threatened. To gauge potential for the species’ restoration in Florida, USA, we conducted an assisted migration experiment where 50 coral fragments of 5 nursery-raised genetic strains (genets) from the upper Florida Keys were moved to 5 sites across 350 km of the offshore reef. Additionally, 4 fragments from the 1 remaining colony of A. palmata in Dry Tortugas National Park (DRTO) were added to the 2 DRTO experimental sites to test for local adaptation. To measure coral performance, we tracked coral survival, calcification, growth, and condition from May 2018 to October 2019. All 24 corals relocated to the DRTO sites survived and calcified ~85% faster than the fewer surviving corals transplanted to the 2 upper Keys sites. While coral survival across the entire experiment did not depend on genet, there was a weak but statistically significant genetic effect on calcification rate among the corals relocated to DRTO. The DRTO native genet was among the fastest growing genets, but it was not the fastest, suggesting a lack of local adaptation at this scale. Our results indicate that DRTO, a remote reef system inhabited by the species during the Holocene and located at the nexus of major ocean currents, may be a prime location for reestablishing A. palmata. Assisted migration of A. palmata to DRTO could restore a sexually reproducing population in <10 yr, thereby promoting the species’ regional recovery.

scholarly journals Experimental antibiotic treatment identifies potential pathogens of white band disease in the endangered Caribbean coral Acropora cervicornis

2014 ◽  
Vol 281 (1788) ◽  
pp. 20140094 ◽  
Author(s):  
M. J. Sweet ◽  
A. Croquer ◽  
J. C. Bythell
Keyword(s):  
Coral Disease ◽  
Causal Agent ◽  
Acropora Palmata ◽  
Acropora Cervicornis ◽  
Coral Diseases ◽  
White Band ◽  
Disease Causation ◽  
Community Shifts ◽  
White Band Disease ◽  
Experimental Treatments

Coral diseases have been increasingly reported over the past few decades and are a major contributor to coral decline worldwide. The Caribbean, in particular, has been noted as a hotspot for coral disease, and the aptly named white syndromes have caused the decline of the dominant reef building corals throughout their range. White band disease (WBD) has been implicated in the dramatic loss of Acropora cervicornis and Acropora palmata since the 1970s, resulting in both species being listed as critically endangered on the International Union for Conservation of Nature Red list. The causal agent of WBD remains unknown, although recent studies based on challenge experiments with filtrate from infected hosts concluded that the disease is probably caused by bacteria. Here, we report an experiment using four different antibiotic treatments, targeting different members of the disease-associated microbial community. Two antibiotics, ampicillin and paromomycin, arrested the disease completely, and by comparing with community shifts brought about by treatments that did not arrest the disease, we have identified the likely candidate causal agent or agents of WBD. Our interpretation of the experimental treatments is that one or a combination of up to three specific bacterial types, detected consistently in diseased corals but not detectable in healthy corals, are likely causal agents of WBD. In addition, a histophagous ciliate ( Philaster lucinda ) identical to that found consistently in association with white syndrome in Indo-Pacific acroporas was also consistently detected in all WBD samples and absent in healthy coral. Treatment with metronidazole reduced it to below detection limits, but did not arrest the disease. However, the microscopic disease signs changed, suggesting a secondary role in disease causation for this ciliate. In future studies to identify a causal agent of WBD via tests of Henle–Koch's postulates, it will be vital to experimentally control for populations of the other potential pathogens identified in this study.

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