ORCID Profile
0000-0001-6476-9263
Current Organisations
Leeds Teaching Hospitals NHS Trust
,
University of New South Wales
,
James Cook University
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: CRC Press
Date: 11-08-2023
Publisher: Frontiers Media SA
Date: 22-07-2020
Publisher: Copernicus GmbH
Date: 14-02-2022
Abstract: Abstract. Coral bleaching events continue to drive the degradation of coral reefs worldwide, causing a shift in the benthic community from coral- to algae-dominated ecosystems. Critically, this shift may decrease the capacity of degraded coral reef communities to maintain net positive accretion during warming-driven stress events (e.g., reef-wide coral bleaching). Here we measured rates of net ecosystem calcification (NEC) and net ecosystem production (NEP) on a degraded coral reef lagoon community (coral cover 10 % and algae cover 20 %) during a reef-wide bleaching event in February 2020 at Heron Island on the Great Barrier Reef. We found that during this bleaching event, rates of NEP and NEC across replicate transects remained positive and did not change in response to bleaching. Repeated benthic surveys over a period of 20 d indicated an increase in the percent area of bleached coral tissue, corroborated by relatively low Symbiodiniaceae densities (∼ 0.6 × 106 cm−2) and dark-adapted photosynthetic yields in photosystem II of corals (∼ 0.5) s led along each transect over this period. Given that a clear decline in coral health was not reflected in the overall NEC estimates, it is possible that elevated temperatures in the water column that compromise coral health enhanced the thermodynamic favorability for calcification in other ahermatypic benthic calcifiers. These data suggest that positive NEC on degraded reefs may not equate to the net positive accretion of a complex, three-dimensional reef structure in a future, warmer ocean. Critically, our study highlights that if coral cover continues to decline as predicted, NEC may no longer be an appropriate proxy for reef growth as the proportion of the NEC signal owed to ahermatypic calcification increases and coral dominance on the reef decreases.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4DT02575J
Abstract: Oligonuclear polypyridylruthenium( ii ) complexes show selectivity for the nucleus of eukaryotic cells with a considerable preference for the RNA-rich nucleolus.
Publisher: CSIRO Publishing
Date: 12-07-2021
DOI: 10.1071/MF21050
Abstract: Climate change is increasing the frequency of marine heatwaves around the world, causing widespread degradation of coral reefs. Endolithic microalgae inhabiting the coral skeleton have been highlighted as potentially important mediators of the consequences of heatwaves on coral reefs. These microalgae often bloom during heat stress due to greater light availability, theoretically delaying coral starvation by providing photoassimilates. However, these microalgae also dissolve coral skeletons at an accelerated rate during marine heatwaves, affecting the structural complexity of the reef. Despite their ecological role, no studies have examined endolithic algal blooms during a natural bleaching event. We quantified blooms of endolithic microalgae in the skeletons of lagoon corals bleaching on Heron Island in the austral summer of 2020. At the peak of heat stress, 20–30% of bleached corals across 9 genera at 3 sites had blooms. They were predominantly seen in branching Acropora spp. (37.8, 65.7 and 66.7% at three sites), which are primary reef builders at Heron Island. At the end of the bleaching event, the overall prevalence varied between 5 and 42%, and nearly all blooms were observed in acroporids. The relative high frequency of these blooms highlights the ongoing need to understand the role of these microbes during coral bleaching events.
Publisher: PeerJ
Date: 27-04-2017
DOI: 10.7287/PEERJ.PREPRINTS.2949V1
Abstract: Elevated sea surface temperatures (SSTs) are linked to an increase in the frequency and severity of bleaching events due to temperatures exceeding corals’ upper thermal limits. The temperatures at which a breakdown of the coral- Symbiodinium endosymbiosis (coral bleaching) occurs are referred to as the upper thermal limits for the coral species. This breakdown of the endosymbiosis results in a reduction of corals’ nutritional uptake, growth, and tissue integrity. Periods of elevated sea surface temperature, thermal stress and coral bleaching are also linked to increased disease susceptibility and an increased frequency of storms which cause injury and physical damage to corals. Herein we aimed to determine the capacity of corals to regenerate and recover from injuries (removal of apical tips) sustained during periods of elevated sea surface temperatures which result in coral stress responses, but which do not result in coral bleaching (i.e. sub-bleaching thermal stress events). In this study, exposure of the species Acropora aspera to an elevated SST of 32°C (2°C below the bleaching threshold, 34°C) was found to result in reduced fluorescence of green fluorescent protein (GFP), reduced skeletal calcification and a lack of branch regrowth at the site of injury, compared to corals maintained under ambient SST conditions (26°C). Corals maintained under normal, ambient, sea surface temperatures expressed high GFP fluorescence at the injury site, underwent a rapid regeneration of the coral branch apical tip within 12 days of sustaining injury, and showed extensive regrowth of the coral skeleton. Taken together, our results have demonstrated that periods of sustained increased sea surface temperatures, below the corals’ bleaching threshold but above long-term summertime averages, impair coral recovery from damage, regardless of the onset or occurrence of coral bleaching .
Publisher: Elsevier BV
Date: 08-2019
DOI: 10.1016/J.CUB.2019.06.077
Abstract: Severe marine heatwaves have recently become a common feature of global ocean conditions due to a rapidly changing climate [1, 2]. These increasingly severe thermal conditions are causing an unprecedented increase in the frequency and severity of mortality events in marine ecosystems, including on coral reefs [3]. The degradation of coral reefs will result in the collapse of ecosystem services that sustain over half a billion people globally [4, 5]. Here, we show that marine heatwave events on coral reefs are biologically distinct to how coral bleaching has been understood to date, in that heatwave conditions result in an immediate heat-induced mortality of the coral colony, rapid coral skeletal dissolution, and the loss of the three-dimensional reef structure. During heatwave-induced mortality, the coral skeletons exposed by tissue loss are, within days, encased by a complex biofilm of phototrophic microbes, whose metabolic activity accelerates calcium carbonate dissolution to rates exceeding accretion by healthy corals and far greater than has been documented on reefs under normal seawater conditions. This dissolution reduces the skeletal density and hardness and increases porosity. These results demonstrate that severe-heatwave-induced mortality events should be considered as a distinct biological phenomenon from bleaching events on coral reefs. We also suggest that such heatwave mortality events, and rapid reef decay, will become more frequent as the intensity of marine heatwaves increases and provides further compelling evidence for the need to mitigate climate change and instigate actions to reduce marine heatwaves.
Publisher: Elsevier BV
Date: 04-2009
Publisher: American Society for Microbiology
Date: 24-02-2021
Abstract: Microbial communities living inside the skeletons of living corals play a variety of important roles within the coral meta-organism, both symbiotic and parasitic. Properly contextualizing the contribution of these enigmatic microbes to the life history of coral reefs requires knowledge of how these endolithic biofilms vary between coral species.
Publisher: Springer Science and Business Media LLC
Date: 17-11-2011
DOI: 10.1038/SREP00160
Publisher: Springer Science and Business Media LLC
Date: 06-07-2015
DOI: 10.1038/SREP11903
Abstract: By cultivating turf algae and aggressively defending their territories, territorial damselfishes in the genus Stegastes play a major role in shaping coral-algal dynamics on coral reefs. The epilithic algal matrix (EAM) inside Stegastes ’ territories is known to harbor high abundances of potential coral disease pathogens. To determine the impact of territorial grazers on coral microbial assemblages, we established a coral transplant inside and outside of Stegastes ’ territories. Over the course of one year, the percent mortality of transplanted corals was monitored and coral s les were collected for microbial analysis. As compared to outside damselfish territories, Stegastes were associated with a higher rate of mortality of transplanted corals. However, 16S rDNA sequencing revealed that territorial grazers do not differentially impact the microbial assemblage of corals exposed to the EAM. Regardless of Stegastes presence or absence, coral transplantation resulted in a shift in the coral-associated microbial community and an increase in coral disease associated potential pathogens. Further, transplanted corals that suffer low to high mortality undergo a microbial transition from a microbiome similar to that of healthy corals to that resembling the EAM. These findings demonstrate that coral transplantation significantly impacts coral microbial communities and transplantation may increase susceptibility to coral disease.
Publisher: Wiley
Date: 10-2022
Abstract: The health of coral reef ecosystems is declining. As research examining this decline has grown, review articles (secondary literature) have emerged. Secondary literature can include narrative reviews, systematic reviews, and bibliometric analyses. Synthesizing secondary literature can influence research directions, as syntheses visualize both the current state of knowledge and trends in research. Therefore, we propose to use the combination of bibliometric mapping and systematic mapping techniques to synthesize the secondary literature on coral health and coral reef decline. We will examine secondary literature on coral health published in peer‐reviewed journals and indexed in Scopus or Web of Science databases. After screening the title, abstract, and keywords of each paper, we will extract information that encompasses the type and purpose of the review, the identified factors affecting coral health, and the health‐related outcomes on coral reefs. We will also conduct a critical appraisal using the Collaboration for Environmental Evidence Synthesis Assessment Tool (CEESAT) criteria for papers that are self‐reported to be systematic reviews. We will also extract bibliometric data to identify author affiliations, collaboration networks, and journals. We will communicate our results from systematic and bibliometric mapping using visualizations and tabulations. Our systematic map aims to reveal gaps and clusters of topics in review articles on coral health. These findings can guide future research into coral health in both primary and secondary literature. Our critical appraisal will evaluate the robustness of systematic reviews, informing researchers on how to identify and conduct high‐quality reviews. Our bibliometric map will uncover the extent and connectivity of researchers synthesizing evidence on coral health, highlighting the ersity (or lack thereof) of those engaging in coral health research.
Publisher: Research Square Platform LLC
Date: 08-07-2020
DOI: 10.21203/RS.3.RS-37102/V1
Abstract: Background: Fish harbour erse microbiomes within their gastro-intestinal system that effect the host’s digestion, nutrition and immunity. Despite the great taxonomic ersity of fish, little is understood about fish microbiome ersity and the factors that determine its structure and composition. Damselfish are important coral reef fish species that play a strong role in determining algae and coral structure of reefs. Broadly, damselfish belong to either of two trophic guilds based on whether they are planktivorous or algae-farming. In this study, we use 16s rRNA sequencing to interrogate the intestinal microbiome of 10 damselfish species (Pomacentridae) from the Great Barrier Reef to compare the composition of their intestinal bacterial assemblages across the planktivorous and algae-farming trophic guilds. Results: We identify core intestinal bacterial taxa for each host fish species. Gammaproteobacteria, belonging to the genus Actinobacillus, were detected in 80 % of s led in iduals and suggests a possible core member of pomacentrid microbiomes. Core microbiomes of algae-farming species were more erse than planktivorous species with farming species sharing 35 ± 22 ASVs and planktivorous sharing 7 ± 3 ASVs. We also provide evidence for significant shifts in bacterial community composition along the intestines. We show that Bacteroidia, Clostridia and Mollicutes bacteria are more abundant in the anterior intestinal regions while Gammaproteobacteria are generally highest in the stomach. Finally, we highlight differences in microbiomes associated with both trophic guilds. Algae-farming and planktivorous damselfish host species significantly differed in their composition of bacteria belonging to Vibrionaceae, Lachnospiraceae and Pasteurellaceae. Conclusions: Our results demonstrate that core intestinal bacterial communities of damselfish reflect host species diet and feeding behaviour, whereby algae-farming hosts have larger and more erse core microbiomes than planktivorous hosts. We suggest that the trophic guild of a host fish species is a strong determinant of microbiome structure.
Publisher: Wiley
Date: 02-10-2015
Publisher: Public Library of Science (PLoS)
Date: 24-10-2011
Publisher: Wiley
Date: 06-06-2023
DOI: 10.1111/ELE.14266
Abstract: Coral reefs are under threat from disease as climate change alters environmental conditions. Rising temperatures exacerbate coral disease, but this relationship is likely complex as other factors also influence coral disease prevalence. To better understand this relationship, we meta‐analytically examined 108 studies for changes in global coral disease over time alongside temperature, expressed using average summer sea surface temperature (SST) and cumulative heat stress as weekly sea surface temperature anomalies (WSSTAs). We found that both rising average summer SST and WSSTA were associated with global increases in the mean and variability in coral disease prevalence. Global coral disease prevalence tripled, reaching 9.92% in the 25 years examined, and the effect of ‘year’ became more stable (i.e. prevalence has lower variance over time), contrasting the effects of the two temperature stressors. Regional patterns erged over time and differed in response to average summer SST. Our model predicted that, under the same trajectory, 76.8% of corals would be diseased globally by 2100, even assuming moderate average summer SST and WSSTA. These results highlight the need for urgent action to mitigate coral disease. Mitigating the impact of rising ocean temperatures on coral disease is a complex challenge requiring global discussion and further study.
Publisher: Springer Science and Business Media LLC
Date: 15-09-2007
Publisher: Wiley
Date: 24-12-2019
DOI: 10.1111/GCB.14901
Abstract: Extreme heat wave events are now causing ecosystem degradation across marine ecosystems. The consequences of this heat‐induced damage range from the rapid loss of habitat‐forming organisms, through to a reduction in the services that ecosystems support, and ultimately to impacts on human health and society. How we tackle the sudden emergence of ecosystem‐wide degradation has not yet been addressed in the context of marine heat waves. An examination of recent marine heat waves from around Australia points to the potential important role that respite or refuge from environmental extremes can play in enabling organismal survival. However, most ecological interventions are being devised with a target of mid to late‐century implementation, at which time many of the ecosystems, that the interventions are targeted towards, will have already undergone repeated and widespread heat wave induced degradation. Here, our assessment of the merits of proposed ecological interventions, across a spectrum of approaches, to counter marine environmental extremes, reveals a lack preparedness to counter the effects of extreme conditions on marine ecosystems. The ecological influence of these extremes are projected to continue to impact marine ecosystems in the coming years, long before these interventions can be developed. Our assessment reveals that approaches which are technologically ready and likely to be socially acceptable are locally deployable only, whereas those which are scalable—for ex le to features as large as major reef systems—are not close to being testable, and are unlikely to obtain social licence for deployment. Knowledge of the environmental timescales for survival of extremes, via respite or refuge, inferred from field observations will help test such intervention tools. The growing frequency of extreme events such as marine heat waves increases the urgency to consider mitigation and intervention tools that support organismal and ecosystem survival in the immediate future, while global climate mitigation and/or intervention are formulated.
Publisher: Inter-Research Science Center
Date: 09-12-2015
DOI: 10.3354/DAO02882
Abstract: White syndrome has been described as one of the most prolific diseases on the Great Barrier Reef. Previously, apoptotic cell death has been described as the mechanism driving the characteristic rapid tissue loss associated with this disease, but the molecular mechanisms controlling apoptotic cell death in coral disease have yet to be investigated. In situ methods were used to study the expression patterns of 2 distinct regulators of apoptosis in Acropora hyacinthus tissues undergoing white syndrome and apoptotic cell death. Apoptotic genes within the Bcl-2 family were not localized in apparently healthy coral tissues. However, a Bcl-2 family member (bax-like) was found to localize to cells and tissues affected by white syndrome and those with morphological evidence for apoptosis. A potential up-regulation of pro-apoptotic or bax-like gene expression in tissues with apoptotic cell death adjacent to disease lesions is consistent with apoptosis being the primary cause of rapid tissue loss in coral affected by white syndrome. Pro-apoptotic (bax-like) expression in desmocytes and the basal tissue layer, the calicodermis, distant from the disease lesion suggests that apoptosis may also underlie the sloughing of healthy tissues associated with the characteristic, rapid spread of tissue loss, evident of this disease. This study also shows that in situ hybridisation is an effective tool for studying gene expression in adult corals, and wider application of these methods should allow a better understanding of many aspects of coral biology and disease pathology.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 24-06-2016
Abstract: The coral microbiome will be key to future reef health
Publisher: Wiley
Date: 06-05-2010
DOI: 10.1111/J.1095-8649.2010.02644.X
Abstract: Evidence of facultative corallivory is documented in three species of obligate coral-dwelling gobies (genus Gobiodon) based on the presence of spirocysts in gut contents. Coral-dwelling gobies also consumed a broad range of other items with gut contents dominated by algae, invertebrates and amorphous material. Dietary similarities between species suggest corallivory may be widespread in this genus.
Publisher: Springer Science and Business Media LLC
Date: 14-06-2013
Publisher: Elsevier BV
Date: 08-2020
Publisher: Inter-Research Science Center
Date: 27-07-2010
DOI: 10.3354/AB00270
Publisher: Frontiers Media SA
Date: 22-02-2016
Publisher: Springer Science and Business Media LLC
Date: 18-04-2023
DOI: 10.1007/S10750-023-05221-7
Abstract: The coral reef crisis has influenced research for over two decades, during which time the capacity of corals to withstand and respond to environmental stress has been documented from the cellular to ecosystem level. Over the past decade, research is increasingly working towards uncovering the extent of coral–bacterial interactions, finding that erse and stable microbial interactions can be indicative of the health of the coral host. However, we have yet to determine at which level of organismal organisation these interactions occur, in particular those with the coral’s photosynthetic dinoflagellate symbionts. This information is critical if we are to understand the impact of stress on meta-organism functioning. Using 16S gene licon sequencing, we investigated the bacterial microbiome of endosymbiotic Symbiodiniaceae from thermally stressed Acropora aspera , under 3 ecologically relevant temperature trajectories (defined as protective, repetitive and single) that are expected under a changing climate. We show that endosymbiotic Symbiodiniaceae host a distinct and erse bacterial assemblage when compared with the A. aspera host. Alphaproteobacteria (mainly Rhodobacteraceae and Bradyrhizobiaceae), from the Rhizobiales order dominated the Symbiodiniaceae microbiome, while Gammaproteobacteria (mainly Endozoicomonadaceae) dominated the coral microbiome. The Symbiodiniaceae core microbiome also reflected the distinct microbiomes of the two partners, specifically, Rhizobiales were not present in the A. aspera core, while Endozoicomonadaceae were not present in the Symbiodiniaceae core. We show the Symbiodiniaceae-associated microbiome was highly responsive to increases in temperature, and the microbial consortium was significantly altered in the Symbiodiniaceae retained in the host exposed to different temperature. Most notably, Myxococcolaes were up to 25-fold higher relative abundance in dinoflagellate partner microbiomes under the single temperature trajectory, compared with the repetitive and control treatments. The distinct composition of bacteria associated with Symbiodiniaceae suggests a previously unrecognised, yet important functional role of these associations to overall coral health, which is increasingly important as reefs decline worldwide. Our study provides the first characterisation of Symbiodiniaceae-associated microbes from a coral host under a range of temperature trajectories occurring on the Great Barrier Reef.
Publisher: Elsevier BV
Date: 03-2023
Publisher: Elsevier BV
Date: 11-2011
Publisher: Frontiers Media SA
Date: 19-05-2022
DOI: 10.3389/FPHYS.2022.804193
Abstract: Coral reefs are amongst the most bio erse ecosystems on earth, and while stony corals create the foundational complexity of these ecosystems, octocorals and anemones contribute significantly to their bio ersity and function. Like stony corals, many octocorals contain Symbiodiniaceae endosymbionts and can bleach when temperatures exceed the species’ upper thermal limit. Here, we report octocoral bleaching susceptibility and resistance within the subtropical Lord Howe Island coral reef ecosystem during and after marine heatwaves in 2019. Octocoral and anemone surveys were conducted at multiple reef locations within the Lord Howe Island lagoon during, immediately after, and 7 months after the heatwaves. One octocoral species, Cladiella sp. 1, experienced bleaching and mortality, with some bleached colonies detaching from the reef structure during the heatwave (presumed dead). Those that remained attached to the benthos survived the event and recovered endosymbionts within 7 months of bleaching. Cladiella sp. 1 Symbiodiniaceae density (in cells per µg protein), chlorophyll a and c 2 per µg protein, and photosynthetic efficiency were significantly lower in bleached colonies compared to unbleached colonies, while chlorophyll a and c 2 per symbiont were higher. Interestingly, no other symbiotic octocoral species of the Lord Howe Island lagoonal reef bleached. Unbleached Xenia cf crassa colonies had higher Symbiodiniaceae and chlorophyll densities during the marine heatwave compared to other monitoring intervals, while Cladiella sp. 2 densities did not change substantially through time. Previous work on octocoral bleaching has focused primarily on gorgonian octocorals, while this study provides insight into bleaching variability in other octocoral groups. The study also provides further evidence that octocorals may be generally more resistant to bleaching than stony corals in many, but not all, reef ecosystems. Responses to marine heating events vary and should be assessed on a species by species basis.
Publisher: Springer Science and Business Media LLC
Date: 17-04-2015
Publisher: Elsevier BV
Date: 2022
DOI: 10.1016/J.JENVMAN.2021.113919
Abstract: Coral bleaching has increasingly impacted reefs worldwide over the past four decades. Despite almost 40 years of research into the mechanistic, physiological, ecological, biophysical and climatic drivers of coral bleaching, metrics to allow comparison between ecological observations and experimental simulations still do not exist. Here we describe a novel metric - experimental Degree Heating Week (eDHW) - with which to standardise the persistently variable thermal conditions employed across experimental studies of coral bleaching by modify the widely used Degree Heating Week (DHW) metric used in ecological studies to standardise cumulative heat loading.
Publisher: Springer Science and Business Media LLC
Date: 21-02-2008
Publisher: Springer Science and Business Media LLC
Date: 09-11-2014
Publisher: Research Square Platform LLC
Date: 16-05-2023
DOI: 10.21203/RS.3.RS-2934705/V1
Abstract: Deep sea benthic habitats are low productivity ecosystems that host an abundance of organisms within the Cnidaria phyla. The technical limitations and the high cost of deep sea surveys have made exploring deep sea environments and the biology of the organisms that inhabit them challenging. In spite of the widespread recognition of Cnidaria's environmental importance in these ecosystems, the microbial assemblage and its role in coral functioning have only been studied for a few deep water corals. Here we explored the prokaryotic ersity of deep sea corals by recovering nucleic acids from museum archive specimens. Firstly, we lified and sequenced the V1-V3 regions of the 16S rRNA gene of specimens held in museum archival storage and utilised these to shed light on the microbial ersity associated with seven families of corals collected from depth in the Coral Sea (depth range 1,309 to 2,959 metres) and Southern Ocean (depth range 1,401 to 2,071 metres) benthic habitats. Most surprisingly, Cyanobacteria were consistently associated with six out of seven coral families from both s ling locations, suggesting that these bacteria are potentially ubiquitous members of the microbiome within these cold water and deep sea organisms. Consistent with previous studies, we show that the bacterial phyla Proteobacteria, Verrucomicrobia, Planctomycetes and Acidobacteriota dominate the microbial community of corals in the deep sea. We also explored the genomes of the genus Mycoplasma , which we identified as associated with specimens of three deep sea coral families, finding evidence that these bacteria may aid the host immune system. Importantly our results show that museum specimens retain components of host microbiome that can provide new insights into the ersity of deep sea coral microbiomes (and potentially other organisms), as well as the ersity of microbes writ large in deep sea ecosystems.
Publisher: Springer Science and Business Media LLC
Date: 20-09-2023
Publisher: The Royal Society
Date: 23-07-2014
Abstract: Microbial community structure on coral reefs is strongly influenced by coral–algae interactions however, the extent to which this influence is mediated by fishes is unknown. By excluding fleshy macroalgae, cultivating palatable filamentous algae and engaging in frequent aggression to protect resources, territorial damselfish (f. Pomacentridae), such as Stegastes , mediate macro-benthic dynamics on coral reefs and may significantly influence microbial communities. To elucidate how Stegastes apicalis and Stegastes nigricans may alter benthic microbial assemblages and coral health, we determined the benthic community composition (epilithic algal matrix and prokaryotes) and coral disease prevalence inside and outside of damselfish territories in the Great Barrier Reef, Australia. 16S rDNA sequencing revealed distinct bacterial communities associated with turf algae and a two to three times greater relative abundance of phylotypes with high sequence similarity to potential coral pathogens inside Stegastes 's territories. These potentially pathogenic phylotypes (totalling 30.04% of the community) were found to have high sequence similarity to those lified from black band disease (BBD) and disease affected corals worldwide. Disease surveys further revealed a significantly higher occurrence of BBD inside S. nigricans 's territories. These findings demonstrate the first link between fish behaviour, reservoirs of potential coral disease pathogens and the prevalence of coral disease.
Publisher: PeerJ
Date: 20-09-2016
DOI: 10.7717/PEERJ.2424
Abstract: In situ visualization of microbial communities within their natural habitats provides a powerful approach to explore complex interactions between microorganisms and their macroscopic hosts. Specifically, the application of fluorescence in situ hybridization (FISH) to simultaneously identify and visualize erse microbial taxa associated with coral hosts, including symbiotic algae ( Symbiodinium ), Bacteria, Archaea, Fungi and protists, could help untangle the structure and function of these erse taxa within the coral holobiont. However, the application of FISH approaches to coral s les is constrained by non-specific binding of targeted rRNA probes to cellular structures within the coral animal tissues (including nematocysts, spirocysts, granular gland cells within the gastrodermis and cnidoglandular bands of mesenterial filaments). This issue, combined with high auto-fluorescence of both host tissues and endosymbiotic dinoflagellates ( Symbiodinium ), make FISH approaches for analyses of coral tissues challenging. Here we outline the major pitfalls associated with applying FISH to coral s les and describe approaches to overcome these challenges.
Publisher: Frontiers Media SA
Date: 07-09-2018
Publisher: Oxford University Press (OUP)
Date: 2023
DOI: 10.1093/IOB/OBAD012
Abstract: Generalist coral species may play an important role in predicting, managing, and responding to the growing coral reef crisis as sea surface temperatures are rising and reef wide bleaching events are becoming more common. Pocilloporids are amongst the most widely distributed and studied of generalist corals, characterized by a broad geographic distribution, phenotypic plasticity, and tolerance of sub-optimal conditions for coral recruitment and survival. Emerging research indicates that microbial communities associated with Pocilloporid corals may be contributing to their persistence on coral reefs impacted by thermal stress however, we lack detailed information on shifts in the coral–bacterial symbiosis during bleaching events across many of the reef habitats these corals are found. Here, we characterized the bacterial communities of healthy and bleached Pocillopora damicornis corals during the bleaching events that occurred during the austral summer of 2020 on Heron Island, on the southern Great Barrier Reef, and the austral summer of 2019 on Lord Howe Island, the most southerly coral reef in Australia. Regardless of reef location, significant differences in α and β ersities, core bacterial community, and inferred functional profile of the bleached microbiome of P. damicornis were not detected. Consistent with previous reports, patterns in the Pocilloporid coral microbiome, including no increase in pathogenic taxa or evidence of dysbiosis, are conserved during bleaching responses. We hypothesize that the resilience of holobiont interactions may aid the Pocilloporids to survive Symbiodiniaceae loss and contribute to the success of Pocilloporids.
Publisher: Wiley
Date: 19-06-2015
DOI: 10.1111/MEC.13257
Abstract: Increasing physical damage on coral reefs from predation, storms and anthropogenic disturbances highlights the need to understand the impact of injury on the coral immune system. In this study, we examined the regulation of the coral immune response over 10 days following physical trauma artificially inflicted on in situ colonies of the coral Acropora aspera, simultaneously with bacterial colonization of the lesions. Corals responded to injury by increasing the expression of immune system-related genes involved in the Toll-like and NOD-like receptor signalling pathways and the lectin-complement system in three phases (<2, 4 and 10 days post-injury). Phenoloxidase activity was also significantly upregulated in two phases (<3 and 10 days post-injury), as were levels of non-fluorescent chromoprotein. In addition, green fluorescent protein expression was upregulated in response to injury from 4 days post-injury, while cyan fluorescent protein expression was reduced. No shifts in the composition of coral-associated bacterial communities were evident following injury based on 16S rRNA gene licon pyrosequencing. Bacteria-specific fluorescence in situ hybridization also showed no evidence of bacterial colonization of the wound or regenerating tissues. Coral tissues showed near-complete regeneration of lesions within 10 days. This study demonstrates that corals exhibit immune responses that support rapid recovery following physical injury, maintain coral microbial homeostasis and prevent bacterial infestation that may compromise coral fitness.
Publisher: Research Square Platform LLC
Date: 15-12-2020
DOI: 10.21203/RS.3.RS-126554/V1
Abstract: Background: Fish harbour erse microbiomes within their gastro-intestinal system that affect the host’s digestion, nutrition and immunity and facilitate resource partitioning in coral reef ecosystems. Despite the great taxonomic ersity of fish, little is understood about fish microbiome ersity and the factors that determine its structure and composition. Damselfish are important coral reef fish species that play a strong role in determining algae and coral structure of reefs. Broadly, damselfish belong to either of two trophic guilds based on whether they are planktivorous or algae-farming. In this study, we use 16s rRNA sequencing to interrogate the intestinal microbiome of 10 damselfish species (Pomacentridae) from the Great Barrier Reef to compare the composition of their intestinal bacterial assemblages across the planktivorous and algae-farming trophic guilds. Results: We identify core intestinal bacterial taxa for each host fish species. Gammaproteobacteria, belonging to the genus Actinobacillus, were detected in 80 % of s led in iduals and suggests a possible core member of pomacentrid microbiomes. Core microbiomes of algae-farming species were more erse than planktivorous species with farming species sharing 35 ± 22 ASVs and planktivorous sharing 7 ± 3 ASVs. We also provide evidence for significant shifts in bacterial community composition along the intestines. We show that Bacteroidia, Clostridia and Mollicutes bacteria are more abundant in the anterior intestinal regions while Gammaproteobacteria are generally highest in the stomach. Finally, we highlight differences in microbiomes associated with both trophic guilds. Algae-farming and planktivorous damselfish host species significantly differed in their composition of bacteria belonging to Vibrionaceae, Lachnospiraceae and Pasteurellaceae. Conclusions: Our results demonstrate that the richness of the core intestinal bacterial communities of damselfish reflects host species diet and trophic guild, whereby algae-farming hosts have larger and more erse core microbiomes than planktivorous hosts. We suggest that algae-farming damselfish within the same species share bacterial taxa that reflect their specialised diets.
Publisher: Wiley
Date: 10-2023
Publisher: American Society for Microbiology
Date: 07-11-2018
Abstract: We propose that the coral holobiont should be conceptualized as a erse transient microbial community that is responsive to the surrounding environment and encompasses a simple, redundant, resident microbiome and a small conserved core microbiome. Most importantly, we show that the coral microbiome is comparable to the microbiomes of other organisms studied thus far. Accurately characterizing the coral-microbe interactions provides an important baseline from which the functional roles and the functional niches within which microbes reside can be deciphered.
Publisher: Springer Science and Business Media LLC
Date: 21-10-2014
DOI: 10.1038/S41559-019-0999-7
Abstract: Research into the microbiomes of natural environments is changing the way ecologists and evolutionary biologists view the importance of microorganisms in ecosystem function. This is particularly relevant in ocean environments, where microorganisms constitute the majority of biomass and control most of the major biogeochemical cycles, including those that regulate Earth's climate. Coastal marine environments provide goods and services that are imperative to human survival and well-being (for ex le, fisheries and water purification), and emerging evidence indicates that these ecosystem services often depend on complex relationships between communities of microorganisms (the 'microbiome') and the environment or their hosts - termed the 'holobiont'. Understanding of coastal ecosystem function must therefore be framed under the holobiont concept, whereby macroorganisms and their associated microbiomes are considered as a synergistic ecological unit. Here, we evaluate the current state of knowledge on coastal marine microbiome research and identify key questions within this growing research area. Although the list of questions is broad and ambitious, progress in the field is increasing exponentially, and the emergence of large, international collaborative networks and well-executed manipulative experiments are rapidly advancing the field of coastal marine microbiome research.
Publisher: Springer Science and Business Media LLC
Date: 06-12-2008
Abstract: Coral bleaching occurs when the endosymbiosis between corals and their symbionts disintegrates during stress. Mass coral bleaching events have increased over the past 20 years and are directly correlated with periods of warm sea temperatures. However, some hypotheses have suggested that reef-building corals bleach due to infection by bacterial pathogens. The 'Bacterial Bleaching' hypothesis is based on laboratory studies of the Mediterranean invading coral, Oculina patagonica, and has further generated conclusions such as the coral probiotic hypothesis and coral hologenome theory of evolution. We aimed to investigate the natural microbial ecology of O. patagonica during the annual bleaching using fluorescence in situ hybridization to map bacterial populations within the coral tissue layers, and found that the coral bleaches on the temperate rocky reefs of the Israeli coastline without the presence of Vibrio shiloi or bacterial penetration of its tissue layers. Bacterial communities were found associated with the endolithic layer of bleached coral regions, and a community dominance shift from an apparent cyanobacterial-dominated endolithic layer to an algal-dominated layer was found in bleached coral s les. While bacterial communities certainly play important roles in coral stasis and health, we suggest environmental stressors, such as those documented with reef-building corals, are the primary triggers leading to bleaching of O. patagonica and suggest that bacterial involvement in patterns of bleaching is that of opportunistic colonization.
Publisher: Research Square Platform LLC
Date: 03-11-2022
DOI: 10.21203/RS.3.RS-1798206/V1
Abstract: 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.
Publisher: Springer Science and Business Media LLC
Date: 17-03-2015
Publisher: Frontiers Media SA
Date: 23-09-2022
DOI: 10.3389/FMARS.2022.985496
Abstract: As sequencing techniques have advanced and become cheaper in recent years, there has been a rapid increase in the number of studies conducted into the role of the microbiome in coral health, physiology, and response to environmental change. However, there is substantial variation in the methodological approaches applied. For ex le, DNA extraction protocols and the types of tissues s led from the coral meta-organism are known to influence the downstream analyses of the lified microbial communities and subsequently the interpretation of the microbiome ersity, stability and role. Studies have generally focused on whole organisms, in which the coral s ling steps homogenize the meta-organism microhabitats, however other studies targeting specific microhabitats have identified sources of variation specific to distinct compartments of the coral’s microbial landscape. Here we present a comparative analysis of methodologies optimized for the generation of coral microbiome data from the coral tissues and whole coral fragments of two commonly studied branching coral genera with distinct tissue structure. We investigate the microbiome of the imperforate Pocillopora , where the coral tissue does not penetrate through the calcium carbonate matrix, and the perforate Acropora , where the coral tissues and skeleton are interwoven throughout the coral branch. Through comparing data generated from different DNA extraction protocols using fixed coral tissues isolated from the coral skeletal structure with fixed whole coral fragments, we identify sources of variation inherent to microbial data generated from different s le types, species, and extraction protocols.
Publisher: American Society for Microbiology
Date: 07-09-2016
Abstract: For ecosystems vulnerable to environmental change, understanding the spatiotemporal stability of functionally crucial symbioses is fundamental to determining the mechanisms by which these ecosystems may persist. The coral Pachyseris speciosa is a successful environmental generalist that succeeds in erse reef habitats. The generalist nature of this coral suggests it may have the capacity to form functionally significant microbial partnerships to facilitate access to a range of nutritional sources within different habitats. Here, we propose that coral is a metaorganism hosting three functionally distinct microbial interactions: a ubiquitous core microbiome of very few symbiotic host-selected bacteria, a microbiome of spatially and/or regionally explicit core microbes filling functional niches ( phylotypes), and a highly variable bacterial community that is responsive to biotic and abiotic processes across spatial and temporal scales ( ,000 phylotypes). We find that this coral hosts upwards of 170,000 distinct phylotypes and provide evidence for the persistence of a select group of bacteria in corals across environmental habitats of the Great Barrier Reef and Coral Sea. We further show that a higher number of bacteria are consistently associated with corals on mesophotic reefs than on shallow reefs. An increase in microbial ersity with depth suggests reliance by this coral on bacteria for nutrient acquisition on reefs exposed to nutrient upwelling. Understanding the complex microbial communities of host organisms across broad biotic and abiotic environments as functionally distinct microbiomes can provide insight into those interactions that are ubiquitous niche symbioses and those that provide competitive advantage within the hosts’ environment. IMPORTANCE Corals have been proposed as the most erse microbial biosphere. The high variability of microbial communities has h ered the identification of bacteria playing key functional roles that contribute to coral survival. Exploring the bacterial community in a coral with a broad environmental distribution, we found a group of bacteria present across all environments and a higher number of bacteria consistently associated with mesophotic corals (60 to 80 m). These results provide evidence of consistent and ubiquitous coral-bacterial partnerships and support the consideration of corals as metaorganisms hosting three functionally distinct microbiomes: a ubiquitous core microbiome, a microbiome filling functional niches, and a highly variable bacterial community.
Publisher: Wiley
Date: 19-06-2019
Abstract: If we are to ensure the persistence of species in an increasingly warm world, of interest is the identification of drivers that affect the ability of an organism to resist thermal stress. Underpinning any organism's capacity for resistance is a complex interplay between biological and physical factors occurring over multiple scales. Tropical coral reefs are a unique system, in that their function is dependent upon the maintenance of a coral-algal symbiosis that is directly disrupted by increases in water temperature. A number of physical factors have been identified as affecting the biological responses of the coral organism under broadscale thermal anomalies. One such factor is water flow, which is capable of modulating both organismal metabolic functioning and thermal environments. Understanding the physiological and hydrodynamic drivers of organism response to thermal stress improves predictive capabilities and informs targeted management responses, thereby increasing the resilience of reefs into the future.
Publisher: BMJ
Date: 31-07-2020
Publisher: F1000 Research Ltd
Date: 10-08-2017
DOI: 10.12688/F1000RESEARCH.11522.2
Abstract: Polyp bailout is an established but understudied coral stress response that involves the detachment of in idual polyps from the colonial form as a means of escaping unfavourable conditions. This may influence both the mortality and asexual recruitment of coral genotypes across a range of species. It has been observed in response to numerous stressors including high salinity and low pH. Polyp expulsion in association with thermal stress has once been described in a geographically restricted, temperate species. We therefore cannot reliably apply this observation to tropical coral reefs around the world, which are increasingly under threat from thermal stress events. We present the first qualitative observation of polyp bailout following acute temperature shock in a near-natural mesocosm experiment. Detached polyps show similar characteristics to those described in previous studies, including the retention of endosymbiotic zooxanthellae and the ability to disperse across short distances. This finding strongly suggests that polyp bailout occurs in tropical coral reef environments and warrants further detailed research into the implication of this response in terms of in idual survival, rapid migration into cooler micro-habitats and local recruitment within the reef environment and its coral community.
Publisher: Inter-Research Science Center
Date: 27-01-2008
DOI: 10.3354/AB00102
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.TIM.2016.11.003
Abstract: Corals are considered one of the most complex microbial biospheres studied to date, hosting thousands of bacterial phylotypes in species-specific associations. There are, however, substantial knowledge gaps and challenges in understanding the functional significance of bacterial communities and bacterial symbioses of corals. The ubiquitous nature of some bacterial interactions has only recently been investigated and an accurate differentiation between the healthy (symbiotic) and unhealthy (dysbiotic) microbial state has not yet been determined. Here we review the complexity of the coral holobiont, coral microbiome ersity, and recently proposed bacterial symbioses of corals. We provide insight into coupling the core microbiome framework with community ecology principals, and draw on the theoretical insights from other complex systems, to build a framework to aid in deciphering ecologically significant microbes within a corals' microbial soup.
Publisher: Elsevier BV
Date: 10-2008
Publisher: Wiley
Date: 18-07-2020
Publisher: Springer Science and Business Media LLC
Date: 15-02-2021
Publisher: Frontiers Media SA
Date: 06-12-2021
DOI: 10.3389/FMARS.2021.664063
Abstract: Coral bleaching events in the marine environment are now occurring globally, and the frequency and severity of these events are increasing. Critically, these events can cause the symbiosis between Symbiodiniaceae and their coral hosts to break down, but how the microbial community within the coral responds to bleaching is still equivocal. We investigated the impact of thermal stress exposure on the meta-organism responses of the generalist scleractinian coral species Pocillopora damicornis . Using mesocosms to recreate warming scenarios previously observed at Heron Island, we show that P. damicornis symbiont densities and photophysiological parameters declined at a similar rate under thermal stress regardless of the length of pre-bleaching thermal stress, defined here as temperatures above the monthly maximum mean (MMM) for Heron Island but below the local bleaching threshold (MMM + 2°C). However, we find that the P. damicornis microbiome remains stable over time regardless of the degree of thermal stress and the accumulation of pre-bleaching thermal stress. Our study therefore suggests that while P. damicornis is physiologically impacted by bleaching temperatures, the microbial community identified through 16S rRNA sequencing remains unchanged at the ASV level throughout bleaching. Understanding the capacity of a generalist species to withstand bleaching events is imperative to characterizing what coral species will exist on coral reefs following disturbances, as it has been suggested that the success of environmental generalist species may simplify community structure and lead to changes in bio ersity following environmental disturbance.
Publisher: American Society for Microbiology
Date: 04-2006
DOI: 10.1128/AEM.72.4.3016-3020.2006
Abstract: Microbial communities play important roles in the functioning of coral reef communities. However, extensive autofluorescence of coral tissues and endosymbionts limits the application of standard fluorescence in situ hybridization (FISH) techniques for the identification of the coral-associated bacterial communities. This study overcomes these limitations by combining FISH and spectral imaging.
Publisher: Oxford University Press (OUP)
Date: 2022
DOI: 10.1093/IOB/OBAC026
Abstract: Fish gastro-intestinal system harbors erse microbiomes that affect the host's digestion, nutrition, and immunity. Despite the great taxonomic ersity of fish, little is understood about fish microbiome and the factors that determine its structure and composition. Damselfish are important coral reef species that play pivotal roles in determining algae and coral population structures of reefs. Broadly, damselfish belong to either of two trophic guilds based on whether they are planktivorous or algae-farming. In this study, we used 16S rRNA gene sequencing to investigate the intestinal microbiome of 5 planktivorous and 5 algae-farming damselfish species (Pomacentridae) from the Great Barrier Reef. We detected Gammaproteobacteria ASVs belonging to the genus Actinobacillus in 80% of s led in iduals across the 2 trophic guilds, thus, bacteria in this genus can be considered possible core members of pomacentrid microbiomes. Algae-farming damselfish had greater bacterial alpha- ersity, a more erse core microbiome and shared 35 ± 22 ASVs, whereas planktivorous species shared 7 ± 3 ASVs. Our data also highlight differences in microbiomes associated with both trophic guilds. For instance, algae-farming damselfish were enriched in Pasteurellaceae, whilst planktivorous damselfish in Vibrionaceae. Finally, we show shifts in bacterial community composition along the intestines. ASVs associated with the classes Bacteroidia, Clostridia, and Mollicutes bacteria were predominant in the anterior intestinal regions while Gammaproteobacteria abundance was higher in the stomach. Our results suggest that the richness of the intestinal bacterial communities of damselfish reflects host species diet and trophic guild.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 08-2023
Publisher: Springer Science and Business Media LLC
Date: 23-03-2017
Publisher: Springer Science and Business Media LLC
Date: 12-08-2006
Publisher: Springer Science and Business Media LLC
Date: 22-06-2015
DOI: 10.1038/SREP10561
Abstract: Worldwide, increasing coastal development has played a major role in shaping coral reef species assemblages, but the mechanisms underpinning distribution patterns remain poorly understood. Recent research demonstrated delayed development in larval fishes exposed to suspended sediment, highlighting the need to further understand the interaction between suspended sediment as a stressor and energetically costly activities such as growth and development that are essential to support biological fitness. We examined the gill morphology and the gill microbiome in clownfish larvae ( Amphiprion percula ) exposed to suspended sediment concentrations (using Australian bentonite) commonly found on the inshore Great Barrier Reef. The gills of larvae exposed to 45 mg L −1 of suspended sediment had excessive mucous discharge and growth of protective cell layers, resulting in a 56% thicker gill epithelium compared to fish from the control group. Further, we found a shift from ‘healthy’ to pathogenic bacterial communities on the gills, which could increase the disease susceptibility of larvae. The impact of suspended sediments on larval gills may represent an underlying mechanism behind the distribution patterns of fish assemblages. Our findings underscore the necessity for future coastal development to consider adverse effects of suspended sediments on fish recruitment and consequently fish populations and ecosystem health.
Publisher: American Society for Microbiology
Date: 15-04-2007
DOI: 10.1128/AEM.02738-06
Abstract: The prevalence of coral-associated fungi was four times higher in diseased Acropora formosa colonies than in healthy colonies. Since taxonomically related fungal species were isolated from diseased and healthy colonies, we suggest that their association with coral may be constitutive but that their abundance is dependent on coral health.
Publisher: Wiley
Date: 28-06-2020
Publisher: Frontiers Media SA
Date: 09-09-2021
DOI: 10.3389/FMARS.2021.710730
Abstract: Ocean warming driven bleaching is one of the greatest threats to zooxanthellate cnidarians in the Anthropocene. Bleaching is the loss of Symbiodiniaceae, chlorophyll, or both from zooxanthellate animals. To quantify bleaching and recovery, standardised methods for quantification of Symbiodiniaceae and chlorophyll concentrations have been developed for reef-building scleractinian corals, but no such standard method has been developed for octocorals. For stony corals, quantification of Symbiodiniaceae and chlorophyll concentrations often relies on normalisation to skeletal surface area or unit of biomass [i.e., protein, ash-free dry weight (AFDW)]. Stiff octocorals do not change their volume, as such studies have used volume and surface area to standardise densities, but soft-bodied octocorals can alter their size using water movement within the animal therefore, Symbiodiniaceae and chlorophyll cannot accurately be measured per unit of surface area and are instead measured in units of Symbiodiniaceae and chlorophyll per μg of host protein or AFDW. Though AFDW is more representative of the full biomass composition than host protein, AFDW is more time and resource intensive. Here, we provide a streamlined methodology to quantify Symbiodiniaceae density, chlorophyll concentration, and protein content in soft-bodied octocorals. This technique uses minimal equipment, does not require freeze-drying or burning s les to obtain ash weight, and is effective for down to 0.2 g wet tissue. Bulk s les can be centrifuged, the Symbiodiniaceae pellet washed, and the supernatant saved for protein analysis. This efficient technique allows for clean, easy to count s les of Symbiodiniaceae with minimal animal protein contamination. Chlorophyll a and c 2 extractions occurs at different rates, with chlorophyll a taking 24 h to extract completely at 4°C and chlorophyll c 2 taking 48 h. Finally, we found that where necessary, wet weight may be used as a proxy for protein content, but the correlation of protein and wet weight varies by species and protein should be used when possible. Overall, we have created a rapid and accurate method for quantification of bleaching markers in octocorals.
Publisher: Springer Science and Business Media LLC
Date: 14-06-2013
Abstract: As a step towards understanding coral immunity we present the first whole transcriptome analysis of the acute responses of Acropora millepora to challenge with the bacterial cell wall derivative MDP and the viral mimic poly I:C, defined immunogens provoking distinct but well characterised responses in higher animals. These experiments reveal similarities with the responses both of arthropods and mammals, as well as coral-specific effects. The most surprising finding was that MDP specifically induced three members of the GiMAP gene family, which has been implicated in immunity in mammals but is absent from Drosophila and Caenorhabditis . Like their mammalian homologs, GiMAP genes are arranged in a tandem cluster in the coral genome. A phylogenomic survey of this gene family implies ancient origins, multiple independent losses and lineage-specific expansions during animal evolution. Whilst functional convergence cannot be ruled out, GiMAP expression in corals may reflect an ancestral role in immunity, perhaps in phagolysosomal processing.
Publisher: Springer Science and Business Media LLC
Date: 13-06-2006
Publisher: Cold Spring Harbor Laboratory
Date: 14-03-2019
DOI: 10.1101/576488
Abstract: Bacterial ersity associated with corals has been studied extensively, however, localization of bacterial associations within the holobiont is still poorly resolved. Here we provide novel insight into the localization of coral-associated microbial aggregates (CAMAs) within tissues of the coral Acropora hyacinthus . In total, 318 and 308 CAMAs were characterized via histological and fluorescent in situ hybridization (FISH) approaches respectively, and shown to be distributed extensively throughout coral tissues collected from five sites in Japan and Australia. The densities of CAMAs within the tissues were negatively correlated with the distance from the coastline (i.e. lowest densities at offshore sites). CAMAs were randomly distributed across the six coral tissue regions investigated. Within each CAMA, bacterial cells had similar morphological characteristics, but bacterial morphologies varied among CAMAs, with at least five distinct types identified. Identifying the location of microorganisms associated with the coral host is a prerequisite for understanding their contributions to fitness. Localization of tissue-specific communities housed within CAMAs is particularly important, as these communities are potentially important contributors to vital metabolic functions of the holobiont.
Publisher: Elsevier BV
Date: 2023
DOI: 10.2139/SSRN.4447125
Publisher: Frontiers Media SA
Date: 16-08-2019
Publisher: MDPI AG
Date: 19-07-2011
DOI: 10.3390/D3030356
Publisher: Springer Science and Business Media LLC
Date: 05-07-2016
Publisher: Wiley
Date: 31-10-2008
DOI: 10.1111/J.1365-2818.2008.02089.X
Abstract: The cells and tissues of many marine invertebrates and their associated flora contain fluorescent pigments and proteins, many of which have been utilized commercially and provide marker molecules in other systems for fluorescence imaging technology. However, in the study of marine invertebrates and their symbioses these naturally occurring molecules have been seen to limit or confound fluorescence microscopy analyses. Here we demonstrate the endogenous fluorescence associated with two marine invertebrates (coral and foraminifera) and describe how these qualities can be utilized in fluorescence microanalyses. Understanding and imaging the ersity of fluorescent molecules provide insight into how fluorescence microscopy techniques can now be applied to these complex systems.
Publisher: Wiley
Date: 11-03-2019
Publisher: Oxford University Press (OUP)
Date: 2021
Abstract: The effects of thermal anomalies on tropical coral endosymbiosis can be mediated by a range of environmental factors, which in turn ultimately influence coral health and survival. One such factor is the water flow conditions over coral reefs and corals. Although the physiological benefits of living under high water flow are well known, there remains a lack of conclusive experimental evidence characterizing how flow mitigates thermal stress responses in corals. Here we use in situ measurements of flow in a variety of reef habitats to constrain the importance of flow speeds on the endosymbiosis of an important reef building species under different thermal regimes. Under high flow speeds (0.15 m s−1) and thermal stress, coral endosymbionts retained photosynthetic function and recovery capacity for longer compared to low flow conditions (0.03 m s−1). We hypothesize that this may be due to increased rates of mass transfer of key metabolites under higher flow, putatively allowing corals to maintain photosynthetic efficiency for longer. We also identified a positive interactive effect between high flow and a pre-stress, sub-lethal pulse in temperature. While higher flow may delay the onset of photosynthetic stress, it does not appear to confer long-term protection sustained exposure to thermal stress (eDHW accumulation equivalent to 4.9°C weeks) eventually overwhelmed the coral meta-organism as evidenced by eventual declines in photo-physiological function and endosymbiont densities. Investigating flow patterns at the scale of metres within the context of these physiological impacts can reveal interesting avenues for coral reef management. This study increases our understanding of the effects of water flow on coral reef health in an era of climate change and highlights the potential to learn from existing beneficial bio-physical interactions for the effective preservation of coral reefs into the future.
Publisher: American Society for Microbiology
Date: 02-2007
DOI: 10.1128/AEM.02172-06
Abstract: Recently, reports of coral disease have increased significantly across the world's tropical oceans. Despite increasing efforts to understand the changing incidence of coral disease, very few primary pathogens have been identified, and most studies remain dependent on the external appearance of corals for diagnosis. Given this situation, our current understanding of coral disease and the progression and underlying causes thereof is very limited. In the present study, we use structural and microbial studies to differentiate different forms of black band disease: atypical black band disease and typical black band disease. Atypical black band diseased corals were infected with the black band disease microbial consortium yet did not show any of the typical external signs of black band disease based on macroscopic observations. In previous studies, these ex les, here referred to as atypical black band disease, would have not been correctly diagnosed. We also differentiate white syndrome from white diseases on the basis of tissue structure and the presence/absence of microbial associates. White diseases are those with dense bacterial communities associated with lesions of symbiont loss and/or extensive necrosis of tissues, while white syndromes are characteristically bacterium free, with evidence for extensive programmed cell death/apoptosis associated with the lesion and the adjacent tissues. The pathology of coral disease as a whole requires further investigation. This study emphasizes the importance of going beyond the external macroscopic signs of coral disease for accurate disease diagnosis.
Publisher: Informa UK Limited
Date: 29-09-2020
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.CUB.2017.04.047
Abstract: Reef-building corals provide the foundation for the structural and biological ersity of coral-reef ecosystems. These massive biological structures, which can be seen from space, are the culmination of complex interactions between the tiny polyps of the coral animal in concert with its unicellular symbiotic algae and a wide ersity of closely associated microorganisms (bacteria, archaea, fungi, and viruses). While reef-building corals have persisted in various forms for over 200 million years, human-induced conditions threaten their function and persistence. The scope for loss associated with the destruction of coral reef systems is economically, biologically, physically and culturally immense. Here, we provide a micro-to-macro perspective on the biology of scleractinian corals and discuss how cellular processes of the host and symbionts potentially affect the response of these reef builders to the wide variety of both natural and anthropogenic stressors encountered by corals in the Anthropocene. We argue that the internal physicochemical settings matter to both the performance of the host and microbiome, as bio-physical feedbacks may enhance stress tolerance through environmentally mediated host priming and effects on microbiome ecological and evolutionary dynamics.
Publisher: PeerJ
Date: 18-08-2017
DOI: 10.7717/PEERJ.3719
Abstract: Elevated sea surface temperatures (SSTs) are linked to an increase in the frequency and severity of bleaching events due to temperatures exceeding corals’ upper thermal limits. The temperatures at which a breakdown of the coral- Symbiodinium endosymbiosis (coral bleaching) occurs are referred to as the upper thermal limits for the coral species. This breakdown of the endosymbiosis results in a reduction of corals’ nutritional uptake, growth, and tissue integrity. Periods of elevated sea surface temperature, thermal stress and coral bleaching are also linked to increased disease susceptibility and an increased frequency of storms which cause injury and physical damage to corals. Herein we aimed to determine the capacity of corals to regenerate and recover from injuries (removal of apical tips) sustained during periods of elevated sea surface temperatures which result in coral stress responses, but which do not result in coral bleaching (i.e., sub-bleaching thermal stress events). In this study, exposure of the species Acropora aspera to an elevated SST of 32 °C (2 °C below the bleaching threshold, 34 °C) was found to result in reduced fluorescence of green fluorescent protein (GFP), reduced skeletal calcification and a lack of branch regrowth at the site of injury, compared to corals maintained under ambient SST conditions (26 °C). Corals maintained under normal, ambient, sea surface temperatures expressed high GFP fluorescence at the injury site, underwent a rapid regeneration of the coral branch apical tip within 12 days of sustaining injury, and showed extensive regrowth of the coral skeleton. Taken together, our results have demonstrated that periods of sustained increased sea surface temperatures, below the corals’ bleaching threshold but above long-term summertime averages, impair coral recovery from damage, regardless of the onset or occurrence of coral bleaching.
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/MF19220
Abstract: Coral bleaching is the dysfunction of the coral–algal endosymbiosis and is characterised as a loss of Symbiodiniaceae cells from host tissues or the loss of photosynthetic pigments. This breakdown of symbiosis occurs as a result of elevated temperature beyond the organism’s thermal threshold. The thermal tipping points within the symbiosis have not yet been well resolved, and the mechanisms underlying the various cellular processes of the corals bleaching response remain unknown. This study characterised the cellular responses of the symbiont Cladocopium sp. (syn. clade C3) within the host coral Acropora aspera during exposure to thermal stress. Exposure to temperatures between 2 and 3°C below the bleaching threshold, equating to 2-degree heating weeks (DHWs), results in changes to the symbiont cell morphology and cell ision rates. Once corals were exposed to 4 DHWs, over 90% of the symbiont cells showed signs of degradation. Although sub-bleaching thermal stress is not sufficient to trigger bleaching alerts at an ecological scale, this stressor substantially affects the coral symbiosis. It is therefore vital that we begin to quantify how sub-bleaching thermal stress affects the fitness of Symbiodiniacea populations, their coral hosts and subsequently reefs worldwide.
Publisher: Springer Science and Business Media LLC
Date: 10-2007
Publisher: Research Square Platform LLC
Date: 09-06-2022
DOI: 10.21203/RS.3.RS-1739757/V1
Abstract: Fish gastro-intestinal system harbours erse microbiomes that affect the host’s digestion, nutrition and immunity. Despite the great taxonomic ersity of fish, little is understood about fish microbiome and the factors that determine its structure and composition. Damselfish are important coral reef species that play pivotal roles in determining algae and coral population structures of reefs. Broadly, damselfish belong to either of two trophic guilds based on whether they are planktivorous or algae-farming. In this study, we used 16S rRNA gene sequencing to investigate the intestinal microbiome of five planktivorous and five algae-farming damselfish species (Pomacentridae) from the Great Barrier Reef. We detected Gammaproteobacteria ASVs belonging to the genus Actinobacillus in 80% of s led in iduals across the two trophic guilds, thus, bacteria in this genus can be considered possible core members of pomacentrid microbiomes. Algae-farming damselfish had greater bacterial alpha- ersity, a more erse core microbiome and shared 35 ± 22 ASVs, whereas planktivorous species shared 7 ± 3 ASVs. Our data also highlight differences in microbiomes associated with both trophic guilds. For instance, algae-farming damselfish were enriched in Pasteurellaceae , whilst planktivorous damselfish in Vibrionaceae . Finally, we show shifts in bacterial community composition along the intestines. ASVs associated with the classes Bacteroidia , Clostridia and Mollicutes bacteria were predominant in the anterior intestinal regions while Gammaproteobacteria abundance was higher in the stomach. Our results suggest that the richness of the intestinal bacterial communities of damselfish reflects host species diet and trophic guild.
Publisher: Wiley
Date: 05-08-2021
Abstract: Coral bleaching has impacted reefs worldwide and the predictions of near‐annual bleaching from over two decades ago have now been realized. While technology currently provides the means to predict large‐scale bleaching, predicting reef‐scale and within‐reef patterns in real‐time for all reef users is limited. In 2020, heat stress across the Great Barrier Reef underpinned the region's third bleaching event in 5 years. Here we review the heterogeneous emergence of bleaching across Heron Island reef habitats and discuss the oceanographic drivers that underpinned variable bleaching emergence. We do so as a case study to highlight how reef end‐user groups who engage with coral reefs in different ways require targeted guidance for how, and when, to alter their use of coral reefs in response to bleaching events. Our case study of coral bleaching emergence demonstrates how within‐reef scale nowcasting of coral bleaching could aid the development of accessible and equitable bleaching response strategies on coral reefs. Also see the video abstract here: youtu.be/N9Tgb8N-vN0
Publisher: Informa UK Limited
Date: 12-2013
Publisher: Elsevier BV
Date: 04-2010
DOI: 10.1016/J.TREE.2009.11.001
Abstract: Microbial communities respond and quickly adapt to disturbance and have central roles in ecosystem function. Yet, the many roles of coral-associated microbial communities are not currently accounted for in predicting future responses of reef ecosystems. Here, we propose that a clearer understanding of coral-associated microbial ersity and its interaction with both host and environment will identify important linkages occurring between the microbial communities and macroecological change. Characterizing these links is fundamental to understanding coral reef resilience and will improve our capacity to predict ecological change.
Publisher: Public Library of Science (PLoS)
Date: 12-04-2023
DOI: 10.1371/JOURNAL.PCLM.0000080
Abstract: Oceanic thermal anomalies are increasing in both frequency and strength, causing detrimental impacts to coral reef communities. Water temperatures beyond the corals optimum threshold causeing coral bleaching and mass mortality, impacting our global coral reef ecosystems, including marginal high-latitude reefs. Coral bleaching and mortality were observed at the southernmost coral reef, Lord Howe Island Marine Park, during the summer of 2019, coinciding with anomalously high sea surface temperatures across the reef system from January-April. Here we document the extent of coral impacts within the Lord Howe Island lagoonal reef and the recovery from bleaching eight-months later. Significant differences in bleaching prevalence were observed across the lagoonal coral reef, ranging from 16 to 83% across offshore and inshore reef regions and with variable onset timing. Coral mortality of up to 40% was recorded in the reef’s most severely impacted near-shore area. The four most dominant species, Stylophora pistillata , Pocillopora damicornis , Porites spp . and Seriatopora hystrix , were the most susceptible to bleaching, with all coral colonies found either bleached or dead at the most affected inshore site during and following peak heat stress. Interestingly, during the eight-months following bleaching, there was no evidence of bleaching recovery (i.e., re-establishment of symbiosis) at the offshore lagoonal site. However, there was a significant increase in the abundance of healthy coral colonies at the inshore site, suggesting the recovery of the surviving bleached corals at this site. Importantly, we found no evidence for bleaching or mortality in the Acropora spp . and minimal bleaching and no mortality in Isopora cuneata during the study period, typically highly susceptible species. Given the isolation of high-latitude reefs such as Lord Howe Island, our results highlight the importance of understanding the impacts of bleaching, mortality and bleaching recovery on coral population structure and resilience of high-latitude coral reefs.
Publisher: Frontiers Media SA
Date: 23-08-2016
Publisher: Elsevier BV
Date: 11-2010
DOI: 10.1016/J.DCI.2010.06.016
Abstract: Reef-building corals are representatives of one of the earliest erging metazoan lineages and are experiencing increases in bleaching events (breakdown of the coral-Symbiodinium symbiosis) and disease outbreaks. The present study investigates the roles of two pattern recognition proteins, the mannose binding lectin Millectin and a complement factor C3-like protein (C3-Am), in the coral Acropora millepora. The results indicate that the innate immune functions of these molecules are conserved and arose early in evolution. C3-Am is expressed in response to injury, and may function as an opsonin. In contrast, Millectin expression is up-regulated in response to lipopolysaccharide and peptidoglycan. These observations, coupled with localization of Millectin in nematocysts in epidermal tissue, and reported binding of pathogens, are consistent with a key role for the lectin in innate immunity. Furthermore, Millectin was consistently detected binding to the symbiont Symbiodinium in vivo, indicating that the Millectin function of recognition and binding of non-self-entities may have been co-opted from an ancient innate immune system into a role in symbiosis.
Publisher: Wiley
Date: 25-02-2021
DOI: 10.1111/GCB.15539
Abstract: Globally, collapse of ecosystems—potentially irreversible change to ecosystem structure, composition and function—imperils bio ersity, human health and well‐being. We examine the current state and recent trajectories of 19 ecosystems, spanning 58° of latitude across 7.7 M km 2 , from Australia's coral reefs to terrestrial Antarctica. Pressures from global climate change and regional human impacts, occurring as chronic ‘presses’ and/or acute ‘pulses’, drive ecosystem collapse. Ecosystem responses to 5–17 pressures were categorised as four collapse profiles—abrupt, smooth, stepped and fluctuating. The manifestation of widespread ecosystem collapse is a stark warning of the necessity to take action. We present a three‐step assessment and management framework (3As Pathway Awareness , Anticipation and Action ) to aid strategic and effective mitigation to alleviate further degradation to help secure our future.
Publisher: Oxford University Press (OUP)
Date: 03-2019
Abstract: The enormous variability in richness, abundance and ersity of unknown bacterial organisms inhabiting the coral microbiome have challenged our understanding of their functional contribution to coral health. Identifying the attributes of the healthy meta-organism is paramount for contemporary approaches aiming to manipulate dysbiotic stages of the coral microbiome. This review evaluates the current knowledge on the structure and mechanisms driving bacterial communities in the coral microbiome and discusses two topics requiring further research to define the healthy coral microbiome. (i) We examine the necessity to establish microbial baselines to understand the spatial and temporal dynamics of the healthy coral microbiome and summarise conceptual and logistic challenges to consider in the design of these baselines. (ii) We propose potential mechanical, physical and chemical mechanisms driving bacterial distribution within coral compartments and suggest experiments to test them. Finally, we highlight aspects of the use of 16S licon sequencing requiring standardization and discuss its contribution to other multi-omics approaches.
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.TIM.2017.06.007
Abstract: In marine ecosystems microbial communities are critical to ocean function, global primary productivity, and biogeochemical cycles. Both prokaryotic and eukaryotic microbes are essential symbionts and mutualists, nonpathogenic invaders, primary pathogens, have been linked to disease emergence, and can underpin broader ecosystem changes. However, in the effort to determine coral-microbial interactions, the structure and function of the eukaryotic microbes of the microbiome have been studied less. Eukaryotic microbes are important members of the microbiome, constitute entire kingdoms of life, and make important contributions to ecosystem function. Here, we outline the roles of eukaryotic microbes in marine systems and their contribution to ecosystem change, and discuss the microeukaryotic microbiome of corals and coral reefs.
Publisher: Elsevier BV
Date: 10-2020
Publisher: Public Library of Science (PLoS)
Date: 15-06-2021
DOI: 10.1371/JOURNAL.PBIO.3001282
Abstract: Success and impact metrics in science are based on a system that perpetuates sexist and racist “rewards” by prioritizing citations and impact factors. These metrics are flawed and biased against already marginalized groups and fail to accurately capture the breadth of in iduals’ meaningful scientific impacts. We advocate shifting this outdated value system to advance science through principles of justice, equity, ersity, and inclusion. We outline pathways for a paradigm shift in scientific values based on multidimensional mentorship and promoting mentee well-being. These actions will require collective efforts supported by academic leaders and administrators to drive essential systemic change.
Publisher: Elsevier BV
Date: 12-2022
DOI: 10.1016/J.TIM.2022.05.013
Abstract: One of the most widespread coral diseases linked to anthropogenic activities and recorded on reefs worldwide is characterized by anomalous growth formations in stony corals, referred to as coral growth anomalies (GAs). The biological functions of GA tissue include limited reproduction, reduced access to resources, and weakened ability to defend against predators. Transcriptomic analyses have revealed that, in some cases, disease progression can involve host genes related to oncogenesis, suggesting that the GA tissues may be malignant neoplasms such as those developed by vertebrates. The number of studies reporting the presence of GAs in common reef-forming species highlights the urgency of a thorough understanding of the pathology and causative factors of this disease and its parallels to higher organism malignant tissue growth. Here, we review the current state of knowledge on the etiology and holobiont features of GAs in reef-building corals.
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2009
End Date: 2009
Funder: Australian Research Council
View Funded ActivityStart Date: 2008
End Date: 2010
Funder: Australian Research Council
View Funded ActivityStart Date: 2013
End Date: 2015
Funder: Australian Research Council
View Funded Activity