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Erinn M Muller - One of the best experts on this subject based on the ideXlab platform.
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disease prevalence and snail predation associated with swell generated damage on the threatened coral Acropora palmata lamarck
Frontiers in Marine Science, 2016Co-Authors: Caroline S Rogers, Erinn M Muller, Allan J Bright, Marilyn E Brandt, Tyler B SmithAbstract:Disturbances such as tropical storms cause coral mortality and reduce coral cover as a direct result of physical damage. Storms can be one of the most important disturbances in coral reef ecosystems, and it is crucial to understand their long-term impacts on coral populations. The primary objective of this study was to determine trends in disease prevalence and snail predation on damaged and undamaged colonies of the threatened coral species, Acropora palmata, following an episode of heavy ocean swells in the US Virgin Islands (USVI). At three sites on St. Thomas and St. John, colonies of A. palmata were surveyed monthly over one year following a series of large swells in March 2008 that fragmented 30 to 93% of colonies on monitored reefs. Post-disturbance surveys conducted from April 2008 through March 2009 showed that swell-generated damage to A. palmata caused negative indirect effects that compounded the initial direct effects of physical disturbance. During the 12 months after the swell event, white pox disease prevalence was 41% higher for colonies that sustained damage from the swells than for undamaged colonies (df = 207, p = 0.01) with greatest differences in disease prevalence occurring during warm water months. In addition, the corallivorous snail, Coralliophila abbreviata, was 46% more abundant on damaged corals than undamaged corals during the 12 months after the swell event (df = 207, p = 0.006).
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genetic susceptibility colony size and water temperature drive white pox disease on the coral Acropora palmata
PLOS ONE, 2014Co-Authors: Erinn M Muller, Robert Van WoesikAbstract:Outbreaks of coral diseases are one of the greatest threats to reef corals in the Caribbean, yet the mechanisms that lead to coral diseases are still largely unknown. Here we examined the spatial-temporal dynamics of white-pox disease on Acropora palmata coral colonies of known genotypes. We took a Bayesian approach, using Integrated Nested Laplace Approximation algorithms, to examine which covariates influenced the presence of white-pox disease over seven years. We showed that colony size, genetic susceptibility of the coral host, and high-water temperatures were the primary tested variables that were positively associated with the presence of white-pox disease on A. palmata colonies. Our study also showed that neither distance from previously diseased individuals, nor colony location, influenced the dynamics of white-pox disease. These results suggest that white-pox disease was most likely a consequence of anomalously high water temperatures that selectively compromised the oldest colonies and the most susceptible coral genotypes.
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early signs of recovery of Acropora palmata in st john us virgin islands
Marine Biology, 2014Co-Authors: Erinn M Muller, Caroline S Rogers, R Van WoesikAbstract:Since the 1980s, diseases have caused significant declines in the population of the threatened Caribbean coral Acropora palmata. Yet it is largely unknown whether the population densities have recovered from these declines and whether there have been any recent shifts in size-frequency distributions toward large colonies. It is also unknown whether colony size influences the risk of disease infection, the most common stressor affecting this species. To address these unknowns, we examined A. palmata colonies at ten sites around St. John, US Virgin Islands, in 2004 and 2010. The prevalence of white-pox disease was highly variable among sites, ranging from 0 to 53 %, and this disease preferentially targeted large colonies. We found that colony density did not significantly change over the 6-year period, although six out of ten sites showed higher densities through time. The size-frequency distributions of coral colonies at all sites were positively skewed in both 2004 and 2010, however, most sites showed a temporal shift toward more large-sized colonies. This increase in large-sized colonies occurred despite the presence of white-pox disease, a severe bleaching event, and several storms. This study provides evidence of slow recovery of the A. palmata population around St. John despite the persistence of several stressors.
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bleaching disease and recovery in the threatened scleractinian coral Acropora palmata in st john us virgin islands 2003 2010
Coral Reefs, 2012Co-Authors: Caroline S Rogers, Erinn M MullerAbstract:A long-term study of the scleractinian coral Acropora palmata in the US Virgin Islands (USVI) showed that diseases, particularly white pox, are limiting the recovery of this threatened species. Colonies of A. palmata in Haulover Bay, within Virgin Islands National Park, St. John, were examined monthly in situ for signs of disease and other stressors from January 2003 through December 2009. During the study, 89.9 % of the colonies (n = 69) exhibited disease, including white pox (87 %), white band (13 %), and unknown (9 %). Monthly disease prevalence ranged from 0 to 57 %, and disease was the most significant cause of complete colony mortality (n = 17). A positive correlation was found between water temperature and disease prevalence, but not incidence. Annual average disease prevalence and incidence remained constant during the study. Colonies generally showed an increase in the estimated amount of total living tissue from growth, but 25 (36.2 %) of the colonies died. Acropora palmata bleached in the USVI for the first time during the 2005 Caribbean bleaching event. Only one of the 23 colonies that bleached appeared to die directly from bleaching. In 2005, corals that bleached had greater disease prevalence than those that did not bleach. Just over half (52 %) of the colonies incurred some physical damage. Monitoring of fragments (broken branches) that were generated by physical damage through June 2007 showed that 46.1 % died and 28.4 % remained alive; the fragments that attached to the substrate survived longer than those that did not. Recent surveys showed an increase in the total number of colonies within the reef area, formed from both asexual and sexual reproduction. Genotype analysis of 48 of the originally monitored corals indicated that 43 grew from sexual recruits supporting the conclusion that both asexual and sexual reproduction are contributing to an increase in colony density at this site.
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bleaching increases likelihood of disease on Acropora palmata lamarck in hawksnest bay st john us virgin islands
Coral Reefs, 2008Co-Authors: Caroline S Rogers, Erinn M Muller, Anthony Spitzack, R Van WoesikAbstract:Anomalously high water temperatures may enhance the likelihood of coral disease outbreaks by increasing the abundance or virulence of pathogens, or by increasing host susceptibility. This study tested the compromised-host hypothesis, and documented the relationship between disease and temperature, through monthly monitoring of Acropora palmata colonies from May 2004 to December 2006, in Hawksnest Bay, St John, US Virgin Islands (USVI). Disease prevalence and the rate of change in prevalence showed a positive linear relationship with water temperature and rate of change in water temperature, respectively, but only in 2005 during prolonged periods of elevated temperature. Both bleached and unbleached colonies showed a positive relationship between disease prevalence and temperature in 2005, but the average area of disease-associated mortality increased only for bleached corals, indicating host susceptibility, rather than temperature per se, influenced disease severity on A. palmata.
Erin K Lipp - One of the best experts on this subject based on the ideXlab platform.
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abundance and multilocus sequence analysis of vibrio bacteria associated with diseased elkhorn coral Acropora palmata of the florida keys
Applied and Environmental Microbiology, 2017Co-Authors: Keri M Kemp, Jason R Westrich, Magdy S Alabady, Martinique L Edwards, Erin K LippAbstract: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.
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spatial homogeneity of bacterial communities associated with the surface mucus layer of the reef building coral Acropora palmata
PLOS ONE, 2015Co-Authors: Dustin W Kemp, James W Porter, Erin K Lipp, Keri M Kemp, Adam R Rivers, John P WaresAbstract:Coral surface mucus layer (SML) microbiota are critical components of the coral holobiont and play important roles in nutrient cycling and defense against pathogens. We sequenced 16S rRNA amplicons to examine the structure of the SML microbiome within and between colonies of the threatened Caribbean reef-building coral Acropora palmata in the Florida Keys. Samples were taken from three spatially distinct colony regions—uppermost (high irradiance), underside (low irradiance), and the colony base—representing microhabitats that vary in irradiance and water flow. Phylogenetic diversity (PD) values of coral SML bacteria communities were greater than surrounding seawater and lower than adjacent sediment. Bacterial diversity and community composition was consistent among the three microhabitats. Cyanobacteria, Bacteroidetes, Alphaproteobacteria, and Proteobacteria, respectively were the most abundant phyla represented in the samples. This is the first time spatial variability of the surface mucus layer of A. palmata has been studied. Homogeneity in the microbiome of A. palmata contrasts with SML heterogeneity found in other Caribbean corals. These findings suggest that, during non-stressful conditions, host regulation of SML microbiota may override diverse physiochemical influences induced by the topographical complexity of A. palmata. Documenting the spatial distribution of SML microbes is essential to understanding the functional roles these microorganisms play in coral health and adaptability to environmental perturbations.
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systematic analysis of white pox disease in Acropora palmata of the florida keys and role of serratia marcescens
Applied and Environmental Microbiology, 2015Co-Authors: Jessica Joyner, Kathryn P Sutherland, James W Porter, Dustin W Kemp, Brett Berry, Ashton Griffin, Molly H B Amador, Hunter K G Noren, Erin K LippAbstract:ABSTRACT White 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 by Serratia marcescens) versus general WPD signs. Six reefs in the Florida Keys were surveyed between 2011 and 2013 to determine the disease status of A. palmata and the prevalence of S. marcescens. WPD was noted at four of the six reefs, with WPD lesions found on 8 to 40% of the colonies surveyed. S. marcescens was 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. marcescens was detected with greater frequency in A. palmata than in the overlying water column, regardless of disease status ( P = 0.0177). S. marcescens could not be cultured from A. palmata but 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. Pathogenic S. marcescens was 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.
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human pathogen shown to cause disease in the threatened eklhorn coral Acropora palmata
PLOS ONE, 2011Co-Authors: Kathryn P Sutherland, James W Porter, Sameera Shaban, Jessica Joyner, Erin K LippAbstract:Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS), a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments were conducted with A. palmata maintained in closed aquaria to determine infectivity of strain PDR60 from reef and wastewater sources. Strain PDR60 from wastewater and diseased A. palmata caused disease signs in elkhorn coral in as little as four and five days, respectively, demonstrating that wastewater is a definitive source of APS and identifying human strain PDR60 as a coral pathogen through fulfillment of Koch's postulates. A. palmata inoculated with strain PDR60 from C. abbreviata showed limited virulence, with one of three inoculated fragments developing APS signs within 13 days. Strain PDR60 from non-host coral S. siderea showed a delayed pathogenic effect, with disease signs developing within an average of 20 days. These results suggest that C. abbreviata and non-host corals may function as reservoirs or vectors of the APS pathogen. Our results provide the first example of a marine “reverse zoonosis” involving the transmission of a human pathogen (S. marcescens) to a marine invertebrate (A. palmata). These findings underscore the interaction between public health practices and environmental health indices such as coral reef survival.
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human sewage identified as likely source of white pox disease of the threatened caribbean elkhorn coral Acropora palmata
Environmental Microbiology, 2010Co-Authors: Kathryn P Sutherland, James W Porter, Jeffrey W Turner, Brian J Thomas, Erin E Looney, Trevor P Luna, Meredith K Meyers, Carrie J Futch, Erin K LippAbstract:Summary Caribbean elkhorn coral, Acropora palmata, has been decimated in recent years, resulting in the listing of this species as threatened under the United States Endangered Species Act. A major contributing factor in the decline of this iconic species is white pox disease. In 2002, we identified the faecal enterobacterium, Serratia marcescens, as an etiological agent for white pox. During outbreaks in 2003 a unique strain of S. marcescens was identified in both human sewage and white pox lesions. This strain (PDR60) was also identified from corallivorious snails (Coralliophila abbreviata), reef water, and two non-acroporid coral species, Siderastrea siderea and Solenastrea bournoni. Identification of PDR60 in sewage, diseased Acropora palmata and other reef invertebrates within a discrete time frame suggests a causal link between white pox and sewage contamination on reefs and supports the conclusion that humans are a likely source of this disease.
Iliana B Baums - One of the best experts on this subject based on the ideXlab platform.
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what drives phenotypic divergence among coral clonemates of Acropora palmata
Molecular Ecology, 2019Co-Authors: Meghann K Durante, Dana E Williams, Iliana B Baums, Sam Vohsen, Dustin W KempAbstract:: Evolutionary rescue of populations depends on their ability to produce phenotypic variation that is heritable and adaptive. DNA mutations are the best understood mechanisms to create phenotypic variation, but other, less well-studied mechanisms exist. Marine benthic foundation species provide opportunities to study these mechanisms because many are dominated by isogenic stands produced through asexual reproduction. For example, Caribbean acroporid corals are long lived and reproduce asexually via breakage of branches. Fragmentation is often the dominant mode of local population maintenance. Thus, large genets with many ramets (colonies) are common. Here, we observed phenotypic variation in stress responses within genets following the coral bleaching events in 2014 and 2015 caused by high water temperatures. This was not due to genetic variation in their symbiotic dinoflagellates (Symbiodinium "fitti") because each genet of this coral species typically harbours a single strain of S. "fitti". Characterization of the microbiome via 16S tag sequencing correlated the abundance of only two microbiome members (Tepidiphilus, Endozoicomonas) with a bleaching response. Epigenetic changes were significantly correlated with the host's genetic background, the location of the sampled polyps within the colonies (e.g., branch vs. base of colony), and differences in the colonies' condition during the bleaching event. We conclude that long-term microenvironmental differences led to changes in the way the ramets methylated their genomes, contributing to the differential bleaching response. However, most of the variation in differential bleaching response among clonemates of Acropora palmata remains unexplained. This research provides novel data and hypotheses to help understand intragenet variability in stress phenotypes of sessile marine species.
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genotypic variation influences reproductive success and thermal stress tolerance in the reef building coral Acropora palmata
Coral Reefs, 2013Co-Authors: Iliana B Baums, Meghann K Devlindurante, Nicholas R Polato, D Xu, S Giri, Naomi Altman, D Ruiz, John Everett Parkinson, Jennifer N BoulayAbstract:The branching coral Acropora palmata is a foundation species of Caribbean reefs that has been decimated in recent decades by anthropogenic and natural stressors. Declines in population density and genotypic diversity likely reduce successful sexual reproduction in this self-incompatible hermaphrodite and might impede recovery. We investigated variation among genotypes in larval development under thermally stressful conditions. Six two-parent crosses and three four-parent batches were reared under three temperatures and sampled over time. Fertilization rates differed widely with two-parent crosses having lower fertilization rates (5–56 %, mean 22 % ± 22 SD) than batches (from 31 to 87 %, mean 59 % ± 28 SD). Parentage analysis of larvae in batch cultures showed differences in gamete compatibility among parents, coinciding with significant variation in both sperm morphology and egg size. While all larval batches developed more rapidly at increased water temperatures, rate of progression through developmental stages varied among batches, as did swimming speed. Together, these results indicate that loss of genotypic diversity exacerbates already severe limitations in sexual reproductive success of A. palmata. Nevertheless, surviving parental genotypes produce larvae that do vary in their phenotypic response to thermal stress, with implications for adaptation, larval dispersal and population connectivity in the face of warming sea surface temperatures.
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gene discovery in the threatened elkhorn coral 454 sequencing of the Acropora palmata transcriptome
PLOS ONE, 2011Co-Authors: Nicholas R Polato, Cristobal J Vera, Iliana B BaumsAbstract:Background Cnidarians, including corals and anemones, offer unique insights into metazoan evolution because they harbor genetic similarities with vertebrates beyond that found in model invertebrates and retain genes known only from non-metazoans. Cataloging genes expressed in Acropora palmata, a foundation-species of reefs in the Caribbean and western Atlantic, will advance our understanding of the genetic basis of ecologically important traits in corals and comes at a time when sequencing efforts in other cnidarians allow for multi-species comparisons. Results A cDNA library from a sample enriched for symbiont free larval tissue was sequenced on the 454 GS-FLX platform. Over 960,000 reads were obtained and assembled into 42,630 contigs. Annotation data was acquired for 57% of the assembled sequences. Analysis of the assembled sequences indicated that 83–100% of all A. palmata transcripts were tagged, and provided a rough estimate of the total number genes expressed in our samples (∼18,000–20,000). The coral annotation data contained many of the same molecular components as in the Bilateria, particularly in pathways associated with oxidative stress and DNA damage repair, and provided evidence that homologs of p53, a key player in DNA repair pathways, has experienced selection along the branch separating Cnidaria and Bilateria. Transcriptome wide screens of paralog groups and transition/transversion ratios highlighted genes including: green fluorescent proteins, carbonic anhydrase, and oxidative stress proteins; and functional groups involved in protein and nucleic acid metabolism, and the formation of structural molecules. These results provide a starting point for study of adaptive evolution in corals. Conclusions Currently available transcriptome data now make comparative studies of the mechanisms underlying coral's evolutionary success possible. Here we identified candidate genes that enable corals to maintain genomic integrity despite considerable exposure to genotoxic stress over long life spans, and showed conservation of important physiological pathways between corals and bilaterians.
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geographic variation in clonal structure in a reef building caribbean coral Acropora palmata
Ecological Monographs, 2006Co-Authors: Iliana B Baums, Margaret W Miller, Michael E HellbergAbstract:Species that build the physical structure of ecosystems often reproduce clonally, both in terrestrial (e.g., grasses, trees) and marine (e.g., corals, seagrasses) environments. The degree of clonality may vary over a species' range in accordance with the relative success of sexual and asexual recruitment. High genotypic (clonal) diversity of structural species may promote the species diversity and resilience of ecosystems in the face of environmental extremes. Conversely, low genotypic diversity may indicate an asexual strategy to maintain resources and genetic variation during population decline. Here, we use microsatellite markers to assess geographic variation in clonality in the coral Acropora palmata sampled from 26 reefs in eight regions spanning its tropical western Atlantic range (n ¼ 751). Caribbean-wide, the ratio (6SD) of genets (Ng) to sampled ramets (N) was 0.51 6 0.28. Within reefs (30-70 m) and among reefs (10-100 km) within regions, clonal structure varied from being predominantly asexual (Ng/N approaching 0) to purely sexual (Ng/N ¼ 1). However, two genetically isolated regions (western and eastern Caribbean) differed in clonal structure: genotypically depauperate populations (Ng/N ¼ 0.43 6 0.31) with lower densities (0.13 6 0.08 colonies/m 2 ) characterized the western region, while denser (0.30 6 0.21 colonies/m 2 ), genotypically rich stands (Ng/N ¼ 0.64 6 0.17) typified the eastern Caribbean. Genotypic richness (standardized to sample size; Ng/N) and genotypic diversity (Go/Ge) were negatively related to colony density within each province (r 2 ¼ 0.49-0.66, P , 0.001), indicating that dense stands have higher rates of asexual recruitment than less dense populations. Asexual recruitment was not correlated with large- scale disturbance history or abundance of large colonies (potential fragment sources) but was negatively correlated with shelf area (r 2 ¼ 0.57, P , 0.01). We argue that sexual recruitment is more prevalent in the eastern range of A. palmata than the west, and that these geographic differences in the contribution of reproductive modes to population structure may be related to habitat characteristics. The two populations of the threatened A. palmata differ fundamentally in reproductive character and may respond differently to environmental change.
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regionally isolated populations of an imperiled caribbean coral Acropora palmata
Molecular Ecology, 2005Co-Authors: Iliana B Baums, Margaret W Miller, Michael E HellbergAbstract:The movements of larvae between marine populations are difficult to follow directly and have been the subject of much controversy, especially in the Caribbean. The debate centres on the degree to which populations are demographically open, such that depleted populations can be replenished by recruitment from distant healthy populations, or demographically closed and thus in need of local management. Given the depressed state of many tropical reef populations, the understanding of these movements now bears critically on the number, placement, and size of marine reserves. Most genetic analyses assume that dispersal patterns have been stable for thousands of generations, thus they commonly reflect past colonization histories more than ongoing dispersal. Recently developed multilocus genotyping approaches, however, have the demonstrated ability to detect both migration and population isolation over far shorter timescales. Previously, we developed five microsatellite markers and demonstrated them to be both Mendelian and coral-specific. Using these markers and Bayesian analyses, we show here that populations of the imperiled reef-building coral, Acropora palmata , have experienced little or no recent genetic exchange between the western and the eastern Caribbean. Puerto Rico is identified as an area of mixing between the two subregions. As a consequence of this regional isolation, populations in the western and eastern Caribbean should have the potential to adapt to local conditions and will require population-specific management strategies.
Dana E Williams - One of the best experts on this subject based on the ideXlab platform.
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Assessment of threats to Acropora palmata in the Florida Keys: Proximal causes and their relative importance to remnant populations 2004
Offline data, 2020Co-Authors: Dana E Williams, Margaret W Miller, Protected Resources DivisionAbstract:The remaining elkhorn coral populations in the Florida Keys is faced with a variety of natural and anthropogenic pressures that threaten population level recovery including disease, predation, fragmentation and overgrowth by sponges and algae. The objective of this project is to determine the relative importance of each 'threat' among the remaining elkhorn populations in the upper Florida Keys. Fifteen study plots were established at 5 reefs in the upper Florida Keys National Marine Sanctuary. All elkhorn colonies in the study plot were carefully mapped and approximately 12 colonies within each plot were selected randomly and tagged (n=200). Every three months the tagged colonies are photographed and assessed for the presence of any threats and the entire study plot is searched for new 'recruits' to the population. This study will yield information on the current status and distribution of the candidate species Acropora palmata; characterization of threats to this coral including predation, disease and overgrowth as well as relative importance of each threat to the persistence or recovery of this species in the Florida Keys.
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innate immune gene expression in Acropora palmata is consistent despite variance in yearly disease events
bioRxiv, 2020Co-Authors: Benjamin Douglas Young, Margaret W Miller, Dana E Williams, Xaymara M Serrano, Stephanie Rosales, Nikki TraylorknowlesAbstract:Coral disease outbreaks are expected to increase in prevalence, frequency and severity due to climate change and other anthropogenic stressors. This is especially worrying for the Caribbean branching Acropora palmata which has already seen an 80% decrease in its coral cover, with this primarily due to disease. Despite the importance of this species, there has yet to be a characterization of its transcriptomic response to disease exposure. In this study we provide the first transcriptomic analysis of 12 A. palmata genotypes, and their symbiont Symbiodiniaceae, exposed to disease in 2016 and 2017. Year was the primary driver of sample variance for A. palmata and the Symbiodiniaceae. Lower expression of ribosomal genes in the coral, and higher expression of transmembrane ion transport genes in the Symbiodiniaceae indicate that the increased virulence in 2017 may have been due to a dysbiosis between the coral and Symbiodiniaceae. We also identified a conserved suite of innate immune genes responding to the disease challenge that was activated in both years. This included genes from the Toll-like receptor and lectin pathways, and antimicrobial peptides. Co-expression analysis identified a module positively correlated to disease exposure rich in innate immune genes, with D-amino acid oxidase, a gene implicated in phagocytosis and microbiome homeostasis, as the hub gene. The role of D-amino acid oxidase in coral immunity has not been characterized but holds potential as an important enzyme for responding to disease. Our results indicate that A. palmata mounts a similar immune response to disease exposure as other coral species previously studied, but with unique features that may be critical to the survival of this keystone Caribbean species.
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what drives phenotypic divergence among coral clonemates of Acropora palmata
Molecular Ecology, 2019Co-Authors: Meghann K Durante, Dana E Williams, Iliana B Baums, Sam Vohsen, Dustin W KempAbstract:: Evolutionary rescue of populations depends on their ability to produce phenotypic variation that is heritable and adaptive. DNA mutations are the best understood mechanisms to create phenotypic variation, but other, less well-studied mechanisms exist. Marine benthic foundation species provide opportunities to study these mechanisms because many are dominated by isogenic stands produced through asexual reproduction. For example, Caribbean acroporid corals are long lived and reproduce asexually via breakage of branches. Fragmentation is often the dominant mode of local population maintenance. Thus, large genets with many ramets (colonies) are common. Here, we observed phenotypic variation in stress responses within genets following the coral bleaching events in 2014 and 2015 caused by high water temperatures. This was not due to genetic variation in their symbiotic dinoflagellates (Symbiodinium "fitti") because each genet of this coral species typically harbours a single strain of S. "fitti". Characterization of the microbiome via 16S tag sequencing correlated the abundance of only two microbiome members (Tepidiphilus, Endozoicomonas) with a bleaching response. Epigenetic changes were significantly correlated with the host's genetic background, the location of the sampled polyps within the colonies (e.g., branch vs. base of colony), and differences in the colonies' condition during the bleaching event. We conclude that long-term microenvironmental differences led to changes in the way the ramets methylated their genomes, contributing to the differential bleaching response. However, most of the variation in differential bleaching response among clonemates of Acropora palmata remains unexplained. This research provides novel data and hypotheses to help understand intragenet variability in stress phenotypes of sessile marine species.
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thermal stress exposure bleaching response and mortality in the threatened coral Acropora palmata
Marine Pollution Bulletin, 2017Co-Authors: Margaret W Miller, Dana E Williams, Allan J Bright, Rachel E Pausch, Abel ValdiviaAbstract:Abstract Demographic data for Elkhorn coral, Acropora palmata, and in situ water temperature data from seven upper Florida Keys (USA) reefs revealed three warm thermal stress events between 2010 and 2016. During a mild bleaching event in 2011, up to 59% of colonies bleached, but no mortality resulted. In both 2014 and 2015, severe and unprecedented bleaching was observed with up to 100% of colonies bleached. A. palmata live tissue cover declined by one-third following the 2014–2015 events. Colony mortality of mildly- and non-bleached colonies did not differ but increased significantly with more severe bleaching. Increased bleaching prevalence corresponded to maximum daily average water temperatures above 31.3 °C. However, the cumulative days with daily average exceeding 31.0 °C provided a better predictor of bleaching response. The bleaching response of surviving colonies in 2015 was not consistent with acclimatization as most individual colonies bleached at least as badly as in 2014.
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A standard field protocol for testing relative disease resistance in Acropora palmata and Acropora cervicornis
2016Co-Authors: Margaret W Miller, Dana E WilliamsAbstract:Coral disease has been identified as an ongoing threat to the recovery of sustainable coral populations. This document provides a standard field protocol for screening disease resistance traits in the imperiled coral species, Acropora palmata and Acropora cervicornis, particularly genotypes under nursery culture for population enhancement. It is intended to be implemented by practitioners and researchers in coral restoration and provide standardized information on disease resistance that can aid in the design and success of population enhancement efforts.
James W Porter - One of the best experts on this subject based on the ideXlab platform.
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spatial homogeneity of bacterial communities associated with the surface mucus layer of the reef building coral Acropora palmata
PLOS ONE, 2015Co-Authors: Dustin W Kemp, James W Porter, Erin K Lipp, Keri M Kemp, Adam R Rivers, John P WaresAbstract:Coral surface mucus layer (SML) microbiota are critical components of the coral holobiont and play important roles in nutrient cycling and defense against pathogens. We sequenced 16S rRNA amplicons to examine the structure of the SML microbiome within and between colonies of the threatened Caribbean reef-building coral Acropora palmata in the Florida Keys. Samples were taken from three spatially distinct colony regions—uppermost (high irradiance), underside (low irradiance), and the colony base—representing microhabitats that vary in irradiance and water flow. Phylogenetic diversity (PD) values of coral SML bacteria communities were greater than surrounding seawater and lower than adjacent sediment. Bacterial diversity and community composition was consistent among the three microhabitats. Cyanobacteria, Bacteroidetes, Alphaproteobacteria, and Proteobacteria, respectively were the most abundant phyla represented in the samples. This is the first time spatial variability of the surface mucus layer of A. palmata has been studied. Homogeneity in the microbiome of A. palmata contrasts with SML heterogeneity found in other Caribbean corals. These findings suggest that, during non-stressful conditions, host regulation of SML microbiota may override diverse physiochemical influences induced by the topographical complexity of A. palmata. Documenting the spatial distribution of SML microbes is essential to understanding the functional roles these microorganisms play in coral health and adaptability to environmental perturbations.
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systematic analysis of white pox disease in Acropora palmata of the florida keys and role of serratia marcescens
Applied and Environmental Microbiology, 2015Co-Authors: Jessica Joyner, Kathryn P Sutherland, James W Porter, Dustin W Kemp, Brett Berry, Ashton Griffin, Molly H B Amador, Hunter K G Noren, Erin K LippAbstract:ABSTRACT White 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 by Serratia marcescens) versus general WPD signs. Six reefs in the Florida Keys were surveyed between 2011 and 2013 to determine the disease status of A. palmata and the prevalence of S. marcescens. WPD was noted at four of the six reefs, with WPD lesions found on 8 to 40% of the colonies surveyed. S. marcescens was 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. marcescens was detected with greater frequency in A. palmata than in the overlying water column, regardless of disease status ( P = 0.0177). S. marcescens could not be cultured from A. palmata but 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. Pathogenic S. marcescens was 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.
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human pathogen shown to cause disease in the threatened eklhorn coral Acropora palmata
PLOS ONE, 2011Co-Authors: Kathryn P Sutherland, James W Porter, Sameera Shaban, Jessica Joyner, Erin K LippAbstract:Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS), a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments were conducted with A. palmata maintained in closed aquaria to determine infectivity of strain PDR60 from reef and wastewater sources. Strain PDR60 from wastewater and diseased A. palmata caused disease signs in elkhorn coral in as little as four and five days, respectively, demonstrating that wastewater is a definitive source of APS and identifying human strain PDR60 as a coral pathogen through fulfillment of Koch's postulates. A. palmata inoculated with strain PDR60 from C. abbreviata showed limited virulence, with one of three inoculated fragments developing APS signs within 13 days. Strain PDR60 from non-host coral S. siderea showed a delayed pathogenic effect, with disease signs developing within an average of 20 days. These results suggest that C. abbreviata and non-host corals may function as reservoirs or vectors of the APS pathogen. Our results provide the first example of a marine “reverse zoonosis” involving the transmission of a human pathogen (S. marcescens) to a marine invertebrate (A. palmata). These findings underscore the interaction between public health practices and environmental health indices such as coral reef survival.
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human sewage identified as likely source of white pox disease of the threatened caribbean elkhorn coral Acropora palmata
Environmental Microbiology, 2010Co-Authors: Kathryn P Sutherland, James W Porter, Jeffrey W Turner, Brian J Thomas, Erin E Looney, Trevor P Luna, Meredith K Meyers, Carrie J Futch, Erin K LippAbstract:Summary Caribbean elkhorn coral, Acropora palmata, has been decimated in recent years, resulting in the listing of this species as threatened under the United States Endangered Species Act. A major contributing factor in the decline of this iconic species is white pox disease. In 2002, we identified the faecal enterobacterium, Serratia marcescens, as an etiological agent for white pox. During outbreaks in 2003 a unique strain of S. marcescens was identified in both human sewage and white pox lesions. This strain (PDR60) was also identified from corallivorious snails (Coralliophila abbreviata), reef water, and two non-acroporid coral species, Siderastrea siderea and Solenastrea bournoni. Identification of PDR60 in sewage, diseased Acropora palmata and other reef invertebrates within a discrete time frame suggests a causal link between white pox and sewage contamination on reefs and supports the conclusion that humans are a likely source of this disease.
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the etiology of white pox a lethal disease of the caribbean elkhorn coral Acropora palmata
Proceedings of the National Academy of Sciences of the United States of America, 2002Co-Authors: Kathryn L Patterson, James W Porter, Kim B Ritchie, Shawn W Polson, Erich Mueller, Esther C Peters, Deborah L Santavy, Garriet W SmithAbstract:Populations of the shallow-water Caribbean elkhorn coral, Acropora palmata, are being decimated by white pox disease, with losses of living cover in the Florida Keys typically in excess of 70%. The rate of tissue loss is rapid, averaging 2.5 cm2⋅day−1, and is greatest during periods of seasonally elevated temperature. In Florida, the spread of white pox fits the contagion model, with nearest neighbors most susceptible to infection. In this report, we identify a common fecal enterobacterium, Serratia marcescens, as the causal agent of white pox. This is the first time, to our knowledge, that a bacterial species associated with the human gut has been shown to be a marine invertebrate pathogen.
