Download or read book The Role of Shipyard Pollutants in Structuring Coral Reef Microbial Communities Monitoring Environmental Change and the Potential Causes of Coral Disease written by and published by . This book was released on 2006 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: The US Navy operates military bases in tropical and sub-tropical seas that are surrounded by coral reefs. Therefore, the goal of this work has been to develop methods for long-term monitoring of the effects of naval activity on the health of these reef ecosystems. Our research shows that microbes inhabiting the tissues of healthy and diseased coral are sensitive indicators of environmental change associated with harbor and near-shore naval activity. Our integrated analyses indicate that: (1) coral tissue d34N content is the most sensitive ecological indicator to quantify average sewage concentration with the human enteric bacteria found in the BBD microbial consortium; (2) quantitative correlation of seawater (depth, temperature, pollution, light intensity), coral health (physiology, mucus chemistry, symbiotic zooxanthellae diversity), and coral microbial communities indicate that environmental impact exerts the strongest influence on coral microbes. Results have permitted the development of microbial screening to permit identification of threatened reef ecosystems impacted by harbor and near-shore activity.

Download or read book Oil Spills in Coral Reefs written by Rebecca Z. Hoff and published by . This book was released on 2001 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book What is Killing the Corals written by Nitzan Soffer and published by . This book was released on 2013 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corals have multiple roles in maintaining ocean health and are some of the world's most diverse ecosystems. The coral animal is host to a multitude of taxa, including symbiotic dinoflagellate algae, fungi, bacteria, protists, and viruses. Environmental stressors and disease agents can perturb the delicate balance of the coral host and its microbiota, which can lead to disease. This ultimately results in reduced fitness and/or mortality. There are over 30 described coral disease signs, but with a few exceptions, little is known about their potential etiological agents. Without knowledge on the causes of these diseases, little can be done to mitigate future outbreaks. Chapter 1 of this dissertation provides examples for studying novel diseases in difficult to study organisms with the use of metagenomic tools. Armed with these metagenomic tools and electron microscopy, this dissertation aimed to determine potential pathogens in two coral diseases, White Plague disease (WP), and Growth Anomalies (GAs). First, I set to determine whether viruses may be involved in WP disease from a 2010 outbreak in the US Virgin Islands (USVI). In chapter 2, I compared viromes from 21 Montastraea annularis samples (7= Diseased, 7= Diseased=Bleached, 5= Bleached, 2= Healthy) and surrounding seawater (n=2). After comparing the viromes, I found that small circular REP- encoding eukaryotic ssDNA viruses (SCSDv) similar to circo and nano viruses were associated with WP diseased tissue, and thus potential pathogens. Electron microscopy confirmed the presence of viral particles, and absence of bacterial infection in WP diseased tissue. Even though it was likely that viruses are involved with WP it was still important to understand the changes in bacterial community and the roles of bacteriophages during WP coral infection to characterize opportunistic microbes. These questions were addressed in Chapter 3 where I described the bacterial communities and bacteriophage consortia associated with the USVI corals. I also constructed phage-bacteria networks to understand which phages may interact with bacteria of interest (those shown to be differentially abundant in Montastraea annularis of different health states). I determined that there was a range of interaction specificity across the different phages and bacteria. Chapter 4 aimed to elucidate a potential pathogen responsible for Growth Anomalies, a chronic disease resulting in skeletal deformities, loss of symbiotic algae and reduction of fitness in Hawaiin Porites lobata. By comparing microbial and viral metagenomes across health states I was able to determine any changes in composition from healthy and diseased corals. Overall, microbial communities and viral consortia did not vary across health states. The hypothesized Porites spp. symbiont Oceanspirillales was dominant in all libraries. However, relative abundances of taxa in the orders Vibrionales and Verrucomicrobiales were elevated in diseased compared to healthy corals and healthy appearing tissue of GA infected corals. In addition, bacterial functional pathways remained stable across health states, while signatures of virulence factors were elevated in diseased viromes from healthy. Lastly, chapter 5 summarized overall trends of microbes and viruses determined through the studies. In addition, suggestions for future studies were outlined. Overall, this dissertation revealed a potential viral pathogenic group for white plague disease, explored how phages can influence bacterial opportunists in corals of different health states, and determined bacterial orders and virulence factors that are associated with Growth Anomalies. This dissertation includes the first study to find an association between a viral group and coral disease. In addition, this dissertation contains the first (to date) phage-bacterial inferred network constructed from paired phage-bacteria metagenomes.

Download or read book Coral Reefs Global Climate Change written by Robert W. Buddemeier and published by . This book was released on 2004 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Environment and Climate Change on Coral associated Microbial Communities and Trophic Strategies written by James T Price and published by . This book was released on 2020 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global increases in atmospheric CO2 are leading to ocean warming and acidification, causing more frequent occurrences of coral bleaching, outbreaks of disease, and as a result, widespread coral mortality. Yet, some corals appear to be more tolerant of the effects of a changing climate than others. This has been attributed to several parameters of coral physiology, including greater levels of energy reserves and the ability to incorporate more heterotrophic resources, or hosting more thermally tolerant lineages of endosymbiotic algae (i.e., Symbiodiniaceae). The bacteria and archaea associated with a coral, hereafter referred to as microbial communities, are also thought to support corals by changing in response to environmental conditions, potentially providing a first line of defense as corals attempt to acclimatize.

Download or read book Biological Impact Caused by Changes on a Tropical Reef written by Robert S. Jones and published by . This book was released on 1976 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Macro organisms Influence Coral Reef Microbial Communities Via Shedding and Induction written by and published by . This book was released on 2016 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral reef ecosystems are a diverse but declining habitat. Most reefs around the world have transitioned from a coral to algal dominated benthos with the exact cause for this shift remaining elusive. There is recent evidence that microbes associated with algae either directly from the algae surface or via dissolved organic carbon (DOC) stimulation are detrimental to coral health, inducing mortality and providing space for algae recruitment and growth. To address this issue I investigated how multiple reef organisms influence microbial communities in the surrounding water column. I predicted the effluence from various reef macro-organisms would alter the water column microbial community in contrasting ways. This study consisted of an experiment that looked at water column microbes induced by DOC from various reef macro-organisms and a field assessment of microbial communities, comprised of both shed and induced microbes, above replicate patches dominated by a single macro-organism. Both were conducted on the reefs in the Abrolhos Archipelago of Eastern Brazil. The controlled experiment had replicate seawater microbial communities exposed for 30 hours to the presence of the DOC from different benthic organisms including 1) coral (Mussismilia harttii), 2) crustose coralline algae, 3) algae (Stypopodium zonale), and 4) a seawater control. The microbial communities were semi-cultured and sequenced. Metagenomes showed significant changes in microbial taxa and function when grown in the presence of different macro-organisms. In the second experiment, water above replicate macro-organisms including 1) coral (Mussismilia braziliensis), 2)algae (Stypopodium, Dictota and Canistrocarpus), 3) cyanobacterial mats, and 4) zoanthids (Palythoa caribaeorum) were collected in the field and were compared to the water microbes collected 2 m above the reef. Microbial genera were identified in the water column above each macroorganism. At both a broad and specific level, metabolic pathways of microbes influenced by reef macro-organisms were distinctive. These two studies show that dominant benthic macro-organisms influence the microbes in the water column surrounding them, developing a specific “aura-biome”. The aura-biomes may reduce recruitment potential or growth of nonself macro-organisms. Therefore, as a reef changes to non-coral dominated, the microbial environment may transition to be unsuitable for coral growth, establishing a feedback loop.

Download or read book Scientific Framework for Evaluating Coral Reef Resilience to Climate Change written by Hannah Catherine Barkley and published by . This book was released on 2016 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Disentangling Human Degradation from Environmental Constraints written by James Robinson and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Testing ecological theory at macroecological scales may be useful for disentangling abiotic influences from anthropogenic disturbances, and thus provide insights into fundamental processes that structure ecological communities. In tropical coral reef systems, our understanding of community structure is limited to small-scale studies conducted in moderately degraded regions, while larger regional or ocean scale analyses have typically focused on identifying human drivers of reef degradation. In this thesis, my collaborators and I combined stable isotope specimens, underwater visual censuses, and remote sensing data from 43 Pacific islands and atolls in order to examine the relative roles of natural environmental variation and anthropogenic pressures in structuring coral reef fish and benthic communities. First, at unexploited sites on Kiritimati Atoll (Kiribati), isotope estimates indicated that trophic level increased with body size across species and individuals, while negative abundance ~ body size relationships (size spectra) revealed distinct energetic constraints between energy-competing carnivores and energy-sharing herbivores. After demonstrating size structuring of reef fish communities in the absence of humans, we then examined evidence for size-selective exploitation impacts on coral reefs across the Pacific Ocean. Size spectra 'steepened' as human population density increased and proximity to market center decreased, reflecting decreases in large-bodied fish abundance, biomass, turnover rate, and mean trophic level. Depletion of large fish abundances likely diminishes functions such as bioerosion by grazers and food chain connectivity by top predators, further degrading reef community resilience. Next, we considered the relative strengths of abiotic, biotic and anthropogenic influences in determining reef benthic state across spatial scales. We found that from fine (0.25 km2) to coarse (1,024 km2) grain scales the phase shift index (a multivariate metric of the relative cover of hard coral and macroalgal) was primarily predicted by local abiotic and bottom-up influences, such that coral-dominated reefs occurred in warm, productive regions at sites exposed to low wave energy, irrespective of grazing or human impacts. Our size-based analyses of reef fish communities revealed novel exploitation impacts at ocean-basin scales, and provide a foundation for delineating energetic pathways and feeding interactions in complex tropical food webs. Furthermore, we demonstrate that abiotic constraints underpin natural variation among fish and benthic communities of remote uninhabited reefs, emphasizing the importance of accounting for local environmental conditions when developing quantitative baselines for coral reef ecosystems.

Download or read book Monitoring Additional Values Within Reef 2050 Integrated Monitoring and Reporting Program written by Nicole Webster and published by . This book was released on 2019 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Coral reefs are increasingly affected by localised impacts such as declining water quality and global pressures resultingfrom human-induced climate change, which severely alters the natural conditions on reefs and can push dominating benthic life forms towards the limit of their resistance and resilience. Microorganisms play a fundamental role in the functioning and stability of coral reef ecosystems. However, environmental disturbance can trigger alterations to the composition and function of coral reef microbes, with detrimental consequences for biogeochemical cycling and the functioning of the entire coral reef ecosystem. In addition, environmental stress can alter the associated microbiome of reef organisms such as corals, disrupting the holobiont equilibrium,shifting defensive mechanisms and nutrient cycling pathways that contribute tobleaching and disease.Coral reef microorganismscan buffer or exacerbatecumulative impacts via their role in holobiont fitness as well as by modifying energy flowwithin the ecosystem and are therefore central to reef resilience."--Executive summary.

Download or read book The Microbiome and Coral Health written by Sofia Roitman and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral reefs are some of the oldest biological structures in the world and serve as the home and breeding grounds for a third of the ocean's marine life, sustaining key species and fisheries. While coral reefs are homes to a multitude of marine species, they contain multitudes as well; much like other animals corals are also holobionts that play host to a number of different microscopic organisms, such as bacteria, dinoflagellates, and archaea, forming a complex system of symbioses at the cellular level that allow corals to grow and survive. This consortium of microorganisms is collectively referred to as the microbiome. In recent years, the coral microbiome in particular has gained traction in the scientific community due to our ever-growing understanding of the key role microbiomes play across ecosystems and organismal health. Bacterial members of the microbiome can provide essential services to their coral host in the form of nutrient cycling, metabolic complementarity, and the production of antibiotic compounds. The coral microbiome's intrinsic tie to coral health is of growing importance today given the steady decline of coral reefs worldwide. However, studies show that coral microbiomes can vary widely based on species, region, temperature, depth, and season, as well as in their response to different stressors. Current microbiome studies are thus hindered by the lack of baselines (that is, a description of the microbiome of a healthy coral, including transient and stable microbial members) for healthy coral microbiomes, limiting our ability to study the relationship between environmental stressors and holobiont response. My dissertation aims to address both the need for microbial baselines as well as to aid in the understanding of the relationship between the coral microbiome and coral health in the face of abiotic and biotic stressors. To that end, my first data chapter aims to determine how the microbial communities of two Caribbean coral species vary when infected with disease, as well as identify microbial "footprints" pertaining to each disease and microbial community members that are significantly altered in the face of an infection, which could provide insight on changes to the structure and overall function of the corals' microbiome when infected. My second data chapter aims to determine the relationship between the coral microbiome and coral survivorship in poor water quality conditions through a reciprocal transplant between a clear-water reef and a surviving turbid-water reef, as well as to explore the effects of such an environment on the sediment microbiome using metagenomic sequencing. Finally, my third data chapter aims to establish correlations between anthropogenically-impacted reef sites and the reef environment microbiome, and to therefore propose the future use of environmental microbial metagenomes as sources of information on bioindicator taxa, as well as genes and metabolic pathways that could also be used for indicator purposes.

Download or read book Constructing a Toolbox of Geochemical Indicators of Community Composition Shifts in Coral Reef Ecosystems Under Stress written by Isaiah Wesley Bolden and published by . This book was released on 2020 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern coral reef ecosystems house 25% of the planet's entire marine biodiversity in ~ 0.1% of the surface area cover of the ocean and provide numerous ecosystem services for human populations. Unfortunately, these marine rainforests are known to be in a global state of decline, largely due to the impacts of sea-surface warming, ocean acidification, pollution, disease, and other direct human impacts. Numerous studies have proposed that as these stressors increase in reef environments, a pronounced shift from precipitation to dissolution of calcium carbonate (CaCO3) substrates will induce the collapse of habitat-forming coral structures and lead to dominance of macroalgae. Together, these changes lend themselves to a decline in the overall biodiversity of marine organisms hosted in today's reef ecosystems in addition to major losses to global fisheries,erosion of coastal protection, and dissolution of the foundations of many tropical islands. As a means to improve future reef management and adaptation strategies, there has been a recent push for the development of new tools for monitoring the health of coral reefs under environmental stressors. My research follows a forensic geochemistry approach to understand ecological shifts within and between reef ecosystems in the age of anthropogenic climate change. Specifically, I combine discrete and continuous measurements of seawater composition in coral reef environments, mathematical modeling, and high-resolution mass spectrometry to determine the most effective geochemical proxies for changes in reef metabolism and community composition under stress. Here, I will report on (1) the limitations of exploring variability in modern reef metabolism through assumptions of canonical relationships between carbon and oxygen budgets, (2) the development of a high-precision method for detecting variability in the seawater dissolved strontium-to-calcium (Sr/Casw) ratio and its potential as an indicator of calcifier community composition, and (3) variability in the stable carbon isotope (delta-13 C) composition of seawater dissolved inorganic carbon (DIC) on reefs as a potential proxy for benthic primary producer community composition. With the current unprecedented decline of coral reef ecosystems, the ultimate goal of my research is to construct a sophisticated and quantitative toolkit for detecting ecological transitions within these dynamic marine habitats.

Download or read book Trait mediated Effects and the Extended Phenotype written by Anya Leard Brown and published by . This book was released on 2018 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interaction modifiers can induce changes in (a) physio-chemical conditions and (b) phenotypes of individuals, including host-associated microbial communities, thus influencing species interactions. Among the increasingly best-studied holobionts (hosts + microbes) are corals. Corals experience a myriad of stressors, including interactions with algae, which can decrease coral growth and survival. A hypothesized mechanism underlying the deleterious effects of algae on corals involves the release of dissolved organic carbon (DOC), which stimulates microbial growth leading to changes in microbial communities/hypoxia. The microbial effects of algae on corals are context-dependent, and change depending on the physical environment (e.g., water flow) and the presence of other species. One such species is the sessile vermetid gastropod, Cereasignum maximum, which uses its mucus net for food capture. When a mucus net covers a coral in contact with algae, the net can exacerbate the negative effects of algae on corals by 1) decreasing water flow, 2) synergistically decreasing coral growth, and/or 3) leading to changes in the coral's microbial communities, favoring potentially pathogenic groups and/or enhancing stress by changing the concentration of dissolved materials. Using a series of field surveys, lab flume studies, and field experiments, I found that mucus nets reduce water flow and lower oxygen concentrations at the surface of corals. Algal presence led to the greatest changes in microbial communities. Vermetids and algae decrease different aspects of coral growth. I hypothesized that the absence of a strong response of corals to vermetids arose because corals may have acclimatized to the presence of vermetids. To test this hypothesis I conducted a reciprocal transplant study of corals with and without previous exposure to vermetids. I found significant effects of prior exposure of vermetids on coral traits, and plasticity of the microbiome, but no evidence of a weakened vermetid effect. Interestingly, I also found genetic differences between coral on reefs with vs. without vermetids, and suggest vermetids may be part of a coral's extended phenotype. My dissertation demonstrated interaction modifications and trait-mediated effects of vermetids and algae on corals, and showed novel, but likely general mechanisms for these effects involving changes in the coral's microbial community.

Download or read book Synthesis of Water Quality and Coral Reefs in Relation to Sewage Contamination written by Coral Reef Alliance and published by . This book was released on 2015 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Wastewater contamination of groundwater is...harmful to shoreline environments...causing elevated nutrient levels...that alter coral reef growth rates, species distribution, diversity, and abundance, and increase the incidence of coral disease...The following paragraphs discuss what is known about the impacs of sewage on coastal ecosystems and how these impacts are measured, focusing on South Kohala and Puakō, Hawai'i"--Introduction.

Download or read book Tropical Marine Pollution written by E.J. Ferguson Wood and published by Elsevier. This book was released on 1975-01-01 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tropical Marine Pollution

Download or read book The Environment and Co infection Mediate Disease Risk in Corals Through Impacts on the Microbiome and Immunity written by Allison Merrow Tracy and published by . This book was released on 2019 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Disease in natural populations depends on the interaction between a host and a parasite, but the environment may also modify this interaction. In this dissertation, I explore how abiotic and biotic components of a host's environment alter health and disease in the sea fan octocoral, Gorgonia ventalina. As ectotherms, corals are particularly sensitive to the environment and thus a priority for studying broader questions about environmental drivers of disease. The microbiome is an essential component of the holobiont that can shift under stressful conditions and alter host susceptibility. In Chapter 1, I compare sea fan and scleractinian bacterial communities across the warm thermal anomaly of 2010. Bacterial communities shifted in sea fans, but not in the more bleaching-susceptible, reef-building scleractinian, Orbicella faveolata. In Chapter 2, I further explore the role of organisms infecting sea fans by studying co-infecting macroparasites. Co-infection is common in nature and has ecological and evolutionary consequences for disease outbreaks. I surveyed 10 sites in Puerto Rico and determined that one parasite suppressed host immunity, yet did not facilitate a second parasite due to the overriding influence of the environment and host demography. A primary goal at the intersection of eco-immunology and disease ecology is to understand how the environment influences host immunity in multi-parasite systems. I investigate this interplay in Chapter 3 by measuring both cellular immunity and immune gene expression. Laboratory experiments reveal distinct immune responses to two parasites, but immune responses in field populations are dominated by the influence of environment and demography. There were no signs that the parasites influence each other in nature. While disease outbreaks occur even in healthy populations, anthropogenic change may alter disease risk. In Chapter 4, I use field surveys and a laboratory experiment to test how warming and copper pollution influence sea fan immunity and disease. Higher copper and temperature increased disease risk, while also driving nonlinear immune responses to a damaging parasite. This dissertation provides insight into the mechanisms through which biotic and abiotic factors structure disease. Understanding sea fan health is also a look to the future, as octocorals are critical for reef habitat in a changing ocean.

Download or read book Climate Change Effects on Coral Symbioses written by Andrea Chan and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral reefs are already suffering the impacts of global climate change, including mass coral bleaching, unprecedented disease outbreaks, and increased damage from more intense tropical storms. The loss of reefs would be devastating because these ecosystems support a diversity of fishes and invertebrates, as well as ecosystem services like commercially important fisheries, tourism revenue, and coastal protection. The framework of coral reefs is built by scleractinian corals, which form a symbiotic relationship with intracellular dinoflagellates in the family Symbiodiniaceae. Understanding how a multi-faceted stressor like climate change will impact coral symbioses requires research conducted at multiple levels of organization, including gene expression and physiology, population connectivity, and interactions between species. For my thesis, I studied these impacts of climate change using three different scleractinian coral species. To increase our understanding of the cellular mechanisms resulting in coral bleaching, we conducted a chronic heat stress experiment using the facultatively symbiotic northern star coral, Astrangia poculata, which naturally occurs with (symbiotic) and without (aposymbiotic) its algal symbiont Breviolum psygmophilum sometimes on the same coral colony. With replicate symbiotic and aposymbiotic ramets of A. poculata, we could separate the heat stress response of the coral host from the coral in symbiosis with its symbiont, while also characterizing the response of the symbiont. Sustained high temperature stress resulted in photosynthetic dysfunction of the symbiont, including a drop in maximum photosynthesis rate, maximum photochemical efficiency, and the absorbance peak of chlorophyll a. Interestingly, the metabolic rates of symbiotic and aposymbiotic coral hosts were differentially impacted. RNAseq analysis revealed more differentially expressed genes between heat-stressed and control aposymbiotic colonies than heat-stressed and control symbiotic colonies. Notably, aposymbiotic colonies increased the expression of inflammation-associated genes such as nitric oxide synthases. Unexpectedly, the largest transcriptional response was observed between heat-stressed and control B. psygmophilum, including genes involved in photosynthesis, response to oxidative stress, and meiosis. Thus, in contrast with previous studies, the algal symbiont responded more strongly to high temperatures than the coral host, possibly resulting in suppressed immune function of the coral. In a separate study, I developed novel microsatellite markers to assess population and clonal structure in the threatened pillar coral, Dendrogyra cylindrus, and its specific symbiont, Breviolum dendrogyrum. Patterns of population structure differed between host and symbiont, with more restricted gene flow for the symbiont along the Florida Reef Tract. Sites with multiple colonies of D. cylindrus were found to be clonal, with the same genotype of the coral host often associating with the same strain of the algal symbiont. High clonality in Florida may have increased the vulnerability of D. cylindrus to a recent thermal stress-associated disease outbreak, resulting in a precipitous population decline. Lastly, I investigated clonal structure in the lobe coral, Porites lobata, in two regions with similar gradients of abiotic variables and bioeroding mussel densities. While genotypic diversity was lower at Galapagos sites that are more acidic, similar sites in Palau had relatively equal levels of genotypic diversity across an acidification gradient. These contrasting results are likely due to differences in biotic interactions between the two regions, such as the presence of coral-biting triggerfish in the Galapagos that prey on bioeroding mussels. This points to the importance of considering these interactions when predicting how climate change could impact asexual reproduction in foundational species like corals. Overall, the work presented in this thesis highlights the variability of biological responses at different levels of organization in coral reef environments that will continue to be impacted by climate change.