Download or read book Multiple Stressor Effects on Coral Physiology and Biogeochemistry written by Kerri L. Dobson and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increases in atmospheric CO2 are causing the planet to warm. As such, corals are living closer to their upper thermal tolerance limits, leading to decreased coral health and increased mortality. Increasing sea surface temperatures alter the symbiotic relationship between the coral host and endosymbiotic algae, causing coral bleaching. Such mass bleaching events are predicted to increase in frequency and severity over the next few decades. To protect at least 50% of coral reefs, warming would have to be limited to no more than 1.2°C. Thus, global warming presents an immediate threat to coral reefs. The continuing release of anthropogenic CO2 is also leading to ocean acidification (OA): the net dissolution of atmospheric CO2 into the surface ocean leading to decreases in seawater pH, net increases in total dissolved inorganic carbon and bicarbonate species, and a net decrease in carbonate species. OA is known to cause decreases in calcification in some, but not all corals, and can also be dose-dependent. Thus, the increasing temperature and OA in the ocean co-occur. While OA can exacerbate the negative effects of temperature stress on the physiological responses of some coral species, but not others, it is unknown if OA will impede or slow coral recovery from bleaching. Previous studies have shown that coral feeding on zooplankton may serve to mitigate bleaching or OA stress and enhance recovery from such events in some species. Corals acquire fixed carbon (i.e. food) and nutrients in three ways: 1) via photosynthetically fixed carbon translocated to the coral host from the endosymbiotic algae, 2) uptake of dissolved organic carbon by the coral animal’s polyps, and 3) active eating of zooplankton and particulate organic matter by the coral polyps. While photosynthetically derived fixed carbon is critical to maintaining daily metabolism and calcification, heterotrophically derived food is critical for building lipid reserves and tissue growth. It is unknown if heterotrophy could help recovery from bleaching while also under OA conditions, or whether the thermal and pH history of corals may lay the foundation for coral capacity to acclimate to future ocean conditions. In addition, continued coastal development is leading to decreases in coastal water clarity (i.e. the amount of light penetrating the surface) and increases in nutrient concentrations due to anthropogenic run-off. Evidence suggests that modest increases in any one of temperature, nutrients, or light alone is typically beneficial to coral health, while dramatic increases in any one of these variables can have detrimental effects. For corals in the future, moderate increases in nutrients and/or nutrition might mitigate much of the negative impact of OA on coral calcification. Therefore, coral health is directly related to temperature, light, and nutrients acquired from seawater and zooplankton. However, it is unknown whether a slight increase in food availability and decrease in light level could act synergistically in coastal environments to protect corals from elevated temperature and OA stress and provide a refugia from future ocean conditions. Here, I study combinations of the interactive effects of temperature, ocean acidification, food availability, moderate nutrients, and light on corals through three studies to examine the following: 1) the physiological and biogeochemical responses of three coral species to predicted future coastal ocean conditions, 2) the interactive effects of ocean acidification, temperature, and moderate nutrients on coral physiology and biogeochemistry, and 3) the effect of ocean acidification and feeding on recovery rates of corals following single and annual bleaching.

Download or read book Multiple Stressor Effects on Coral Reefs written by Stephen Shigeyoshi Ban and published by . This book was released on 2014 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Future of Coral Reefs Subject to Rapid Climate Change Lessons from Natural Extreme Environments written by Emma F. Camp and published by Frontiers Media SA. This book was released on 2019-01-22 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examination of corals and reef-associated organisms which endure in extreme coral reef environments is challenging our understanding of the conditions that organisms can survive under. By studying individuals naturally adapted to unfavorable conditions, we begin to better understand the important traits required to survive rapid environmental and climate change. This Research Topic, comprising reviews, and original research articles, demonstrates the current state of knowledge regarding the diversity of extreme coral habitats, the species that have been studied, and the knowledge to-date on the mechanisms, traits and trade-offs that have facilitated survival.

Download or read book Physiology and Biogeochemistry of Corals Subjected to Repeat Bleaching and Combined Ocean Acidification and Warming written by Verena Schoepf and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral skeletal carbon isotopes are important paleo-climate proxies and have the potential to record past bleaching events. However, they are often confounded by strong kinetic isotope effects that can mask the bleaching signal in the skeleton and compromise overall accuracy of the proxy. A proposed data correction to remove kinetic isotope effects was tested for the first time using bleached corals. In addition, it was tested if photosynthesis to respiration (P/R) ratios can be reliably calculated from coral isotopes. We found that the data correction did not effectively remove kinetic isotope effects, and that isotope-based P/R ratios are in poor agreement with P/R ratios measured by respirometry. Therefore, the data correction should not be routinely applied to paleo-climate reconstruction, and P/R ratios should be obtained by respirometry only.

Download or read book Biogeochemistry and Physiology of Bleached and Recovering Hawaiian and Caribbean Corals written by Stephen J. Levas and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Coral reefs are declining globally due to a combination of direct and indirect human impacts. Much of this decline can be attributed to prolonged exposure to elevated sea surface temperatures which induces coral bleaching - a process whereby corals lose their endosymbionts and/or their endosymbiotic pigments resulting in corals that appear pale or white. Corals have extremely different responses to bleaching events: some corals bleach and die, others bleach and recover, and some do not visibly bleach at all. In the absence of abundant photosynthetically fixed C, corals may rely on one or more of the following strategies to sustain themselves and promote recovery: (1) catabolize stored energy reserves, including lipids, carbohydrates, and/or proteins, (2) reduce respiration rates, (3) decrease skeletal growth, (4) increase heterotrophy or (5) shuffle or change their endosymbiont type(s). Although mounding species of coral have been shown to survive bleaching events in greater abundance than branching species, the underlying mechanism(s) for mounding coral resilience is unknown. Furthermore, controlled bleaching and recovery experiments coupled with detailed carbon budgets that incorporate autotrophy and multiple heterotrophic sources (i.e. zooplankton and dissolved organic carbon) do not exist for Caribbean corals. Therefore, two controlled tank experiments, one in Hawaii and the other in Puerto Morelos, Mexico were conducted to understand the bleaching and recovery responses in the Hawaiian coral Porites lobata and the three Caribbean corals Montastraea faveolata, Porites astreoides, and Porites divaricata. Four major findings were observed: 1) Bleaching resilience in the mounding coral P. lobata is due to it harboring a thermally tolerant endosymbiont type combined with an ability to actively metabolize zooplankton acquired C and utilize DOC as a significant fixed C source, 2) Bleached P. astreoides were capable of meeting greater than 100% of metabolic demand by increasing feeding rates, 3) All Caribbean corals took up dissolved organic carbon as a source of fixed carbon when bleached, 4) M. faveolata and P. astreoides are more resilient to single bleaching than P. divaricata. This study represents the first comprehensive assessment of the underlying traits that confer bleaching resilience in a mounding Hawaiian coral. Furthermore, these studies represent a comprehensive physiological and biogeochemical analysis of bleached and recovering Caribbean corals and the first to detail their carbon budgets. The ability for bleached corals to maintain high photosynthetic capacity coupled with the ability to utilize exogenous C sources appears to be an underlying theme in resilience to bleaching. Based on these findings, species such as P. lobata, M. faveolata, and to a lesser extent P. astreoides are more likely to survive a single bleaching event than the branching P. divaricata or the previously studied branching coral P. compressa.

Download or read book The Cellular Stress Response and Physiological Adaptations of Corals Subjected to Environmental Stressors and Pollutants written by Davide Seveso and published by Frontiers Media SA. This book was released on 2022-07-18 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Corals in a Stressful World written by Emily Darling and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diverse anthropogenic and natural disturbances affect ecosystems, with the potential to provoke synergies and other 'ecological surprises' that may impede our ability to predict and mitigate the impacts of multiple stressors. This thesis examines the impacts of stressors on populations and communities to establish the prevalence of synergies and identify ecological factors that influence interactions between stressors. First, I quantify the magnitude of multiple stressor interactions using a meta-analysis of published factorial studies, and find that synergies are as common as two other types of interactions, antagonisms and simple additive effects. Then, I turn my focus to coral reefs, an ecosystem that is expected to be particularly vulnerable to the impacts of synergies and stressor interactions. Using a long-term time-series of coral cover data in Kenya, I quantify the impacts of two common stressors, fishing and climate change-induced coral bleaching, and conclude that these stressors do not interact synergistically but instead have a weakly additive or antagonistic effect. The next two chapters investigate the impacts of multiple stressors on coral community dynamics in Kenya. I first propose a new approach to quantitatively classify the diversity of scleractinian corals into four life-history strategies based on species traits. I then apply these life-history groupings to Kenyan corals and show that the composition of life histories can, in part, explain the long-term impacts of fishing and coral bleaching, although life histories do overlook variability within coral communities. Finally, I discuss the implications of my results for our understanding of coral reef resilience to the cumulative impacts of stressors. Specifically, I consider how managing local impacts may have counterintuitive effects on the resilience of coral reefs to global climate change. This thesis highlights the importance of community dynamics for understanding the complex interactions among stressors and provides novel insights for conservation and management actions that attempt to mitigate the impacts of multiple stressors in an increasingly stressful world.

Download or read book A Research Review of Interventions to Increase the Persistence and Resilience of Coral Reefs written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-05-05 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral reef declines have been recorded for all major tropical ocean basins since the 1980s, averaging approximately 30-50% reductions in reef cover globally. These losses are a result of numerous problems, including habitat destruction, pollution, overfishing, disease, and climate change. Greenhouse gas emissions and the associated increases in ocean temperature and carbon dioxide (CO2) concentrations have been implicated in increased reports of coral bleaching, disease outbreaks, and ocean acidification (OA). For the hundreds of millions of people who depend on reefs for food or livelihoods, the thousands of communities that depend on reefs for wave protection, the people whose cultural practices are tied to reef resources, and the many economies that depend on reefs for fisheries or tourism, the health and maintenance of this major global ecosystem is crucial. A growing body of research on coral physiology, ecology, molecular biology, and responses to stress has revealed potential tools to increase coral resilience. Some of this knowledge is poised to provide practical interventions in the short-term, whereas other discoveries are poised to facilitate research that may later open the doors to additional interventions. A Research Review of Interventions to Increase the Persistence and Resilience of Coral Reefs reviews the state of science on genetic, ecological, and environmental interventions meant to enhance the persistence and resilience of coral reefs. The complex nature of corals and their associated microbiome lends itself to a wide range of possible approaches. This first report provides a summary of currently available information on the range of interventions present in the scientific literature and provides a basis for the forthcoming final report.

Download or read book The Cellular Stress Response and Physiological Adaptations of Corals Subjected to Environmental Stressors and Pollutants volume II written by Davide Seveso and published by Frontiers Media SA. This book was released on 2024-09-06 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Given the success of the first edition of The Cellular Stress Response and Physiological Adaptations of Corals Subjected to Environmental Stressors and Pollutants and the continuing advances in the field, we are pleased to announce the Volume II. Coral reefs are among the most biologically diverse and economically important ecosystems on the planet, providing several ecosystem services that are vital to humans. However, the health of corals worldwide is seriously threatened by a multitude of factors. Biotic stressors, such as predation outbreaks and epizootic diseases, and abiotic factors, including abnormally elevated and low sea temperatures, ocean acidification, high UV radiations, changes in salinity, are increasing the occurrence of local and mass coral bleaching events. Additionally, anthropogenic activities such as industrial pollution, coastal development, nutrient input, and recreational activities are leading to further reef degradation and mortality around the world.

Download or read book Coral Reefs and Climate Change written by Jonathan Turnbull Phinney and published by American Geophysical Union. This book was released on 2006-01-10 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Coastal and Estuarine Studies, Volume 61. The effects of increased atmospheric carbon dioxide and related climate change on shallow coral reefs are gaining considerable attention for scientific and economic reasons worldwide. Although increased scientific research has improved our understanding of the response of coral reefs to climate change, we still lack key information that can help guide reef management. Research and monitoring of coral reef ecosystems over the past few decades have documented two major threats related to increasing concentrations of atmospheric CO2: (1) increased sea surface temperatures and (2) increased seawater acidity (lower pH). Higher atmospheric CO2 levels have resulted in rising sea surface temperatures and proven to be an acute threat to corals and other reef-dwelling organisms. Short periods (days) of elevated sea surface temperatures by as little as 1–2°C above the normal maximum temperature has led to more frequent and more widespread episodes of coral bleaching-the expulsion of symbiotic algae. A more chronic consequence of increasing atmospheric CO2 is the lowering of pH of surface waters, which affects the rate at which corals and other reef organisms secrete and build their calcium carbonate skeletons. Average pH of the surface ocean has already decreased by an estimated 0.1 unit since preindustrial times, and will continue to decline in concert with rising atmospheric CO2. These climate-related Stressors combined with other direct anthropogenic assaults, such as overfishing and pollution, weaken reef organisms and increase their susceptibility to disease.

Download or read book The Biology of Coral Reefs written by Charles R. C. Sheppard and published by Oxford University Press. This book was released on 2018 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral reefs represent the most spectacular and diverse marine ecosystem on the planet as well as a critical source of income for millions of people. However, the combined effects of human activity have led to a rapid decline in the health of reefs worldwide, with many now facing complete destruction. Their world-wide deterioration and over-exploitation has continued and even accelerated in many areas since the publication of the first edition in 2009. At the same time, there has been a near doubling in the number of scientific papers that have been written in this short time about coral reef biology and the ability to acclimate to ocean warming and acidification. This new edition has been thoroughly revised and updated, incorporating the significant increase in knowledge gained over the last decade whilst retaining the book's focus as a concise and affordable overview of the field. The Biology of Coral Reefs provides an integrated overview of the function, physiology, ecology, and behaviour of coral reef organisms. Each chapter is enriched with a selection of 'boxes' on specific aspects written by internationally recognised experts. As with other books in the Biology of Habitats Series, the emphasis in this book is on the organisms that dominate this marine environment although pollution, conservation, climate change, and experimental aspects are also included. Indeed, particular emphasis is placed on conservation and management due to the habitat's critically endangered status. A global range of examples is employed which gives the book international relevance.

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.

Download or read book A Decision Framework for Interventions to Increase the Persistence and Resilience of Coral Reefs written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-08-29 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral reefs are critical to ocean and human life because they provide food, living area, storm protection, tourism income, and more. However, human-induced stressors, such as overfishing, sediment, pollution, and habitat destruction have threatened ocean ecosystems globally for decades. In the face of climate change, these ecosystems now face an array of unfamiliar challenges due to destructive rises in ocean temperature, acidity and sea level. These factors lead to an increased frequency of bleaching events, hindered growth, and a decreasing rate of calcification. Research on interventions to combat these relatively new stressors and a reevaluation of longstanding interventions is necessary to understand and protect coral reefs in this changing climate. Previous research on these methods prompts further questions regarding the decision making process for site-specific interventions. A Decision Framework for Interventions to Increase the Persistence and Resilience of Coral Reefs builds upon a previous report that reviews the state of research on methods that have been used, tested, or proposed to increase the resilience of coral reefs. This new report aims to help coral managers evaluate the specific needs of their site and navigate the 23 different interventions described in the previous report. A case study of the Caribbean, a region with low coral population plagued by disease, serves as an example for coral intervention decision making. This report provides complex coral management decision making tools, identifies gaps in coral biology and conservation research, and provides examples to help individuals and communities tailor a decision strategy to a local area.

Download or read book Interactive Effects of Environment and Neighborhood on Coral Physiology and Demography written by Jamie Kerlin and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral reefs will continue to degrade as disturbances and extreme environmental variability become more severe. While these abiotic factors have strong effects on coral, corals are also affected by surrounding organisms, or their neighbors. The biological responses to disturbance and neighbors are likely interactive, however, few studies address both biotic and abiotic interactions in concert. This thesis consists of two studies testing the interactive effects of disturbance and neighbors on coral survivorship and physiology in Moorea, French Polynesia. [...]

Download or read book Physiology and Biogeochemistry of Bleached and Recovering Corals from Hawaii written by Lisa Jacqueline Rodrigues and published by . This book was released on 2005 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physiology and Biogeochemistry of Bleaches and Recovering Corals from Hawaii written by Lisa Jacqueline Rodrigues and published by . This book was released on 2005 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coral Reefs of the Red Sea written by Christian R. Voolstra and published by Springer. This book was released on 2019-05-07 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is a complete review and reference work for scientists, engineers, and students concerned with coral reefs in the Red Sea. It provides an up-to-date review on the geology, ecology, and physiology of coral reef ecosystems in the Red Sea, including data from most recent molecular studies. The Red Sea harbours a set of unique ecological characteristics, such as high temperature, high alkalinity, and high salinity, in a quasi-isolated environment. This makes it a perfect laboratory to study and understand adaptation in regard to the impact of climate change on marine ecosystems. This book can be used as a general reference, guide, or textbook.