Download or read book Quantifying the Rates and Drivers of Coral and Coral Reef Calcification in the Anthropocene written by Travis Alexander Courtney and published by . This book was released on 2019 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anthropogenic environmental change threatens the ability for many coral reefs to maintain the calcium carbonate structures that provide shoreline protection, fisheries provision, and tourism revenue to human populations worldwide. Rigorous quantification of the rates and drivers of coral and coral reef net ecosystem calcification (NEC) represents a significant challenge but is tantamount for understanding how these services to humanity may be affected by environmental change. This challenge is addressed here by leveraging a combination of field observations, numerical models, and statistical analyses. The major findings showed that extremely large NEC errors of -91% to +1000% can be driven by interacting ±83% uncertainties in the difficult to measure seawater depth and residence time parameters used to calculate NEC. Confidence in NEC rates can nonetheless be improved by leveraging multiple NEC methods as evidenced by the agreement between chemistry and census-based NEC calculated for Hog Reef, Bermuda. Analysis of the environmental drivers of coral and reef-scale calcification at Hog Reef and Crescent Reef, Bermuda showed that temperature was the strongest driver of coral and reef-scale calcification rates with little influence by the other environmental parameters studied. This suggests that reduced warming rates driven by lower global carbon dioxide emissions pathways could maintain Bermudan coral calcification through the twenty-first century. However, more rapid warming can cause coral bleaching that reduces NEC as evidenced by the observation of zero NEC during the fall 2015 coral bleaching event in Kāne'ohe Bay, Hawai'i. The subsequent recovery to pre-bleaching NEC rates by the following summer highlights the capacity of coral reef NEC to rapidly recover in the absence of continued stressors. Conversely, the cumulative effects of 20 years of disturbances on coral calcification capacity (CCC) across the main Hawaiian Islands, Mo'orea, Florida Keys reef tract, and St. John revealed disturbance-driven reductions in CCC and community-level shifts in contributions to CCC from competitive to weedy corals that may increase CCC resilience to future disturbances. This dissertation collectively improves projections for how the Anthropocene may change reef structures and the services they provide humanity by advancing our understanding of the rates and drivers of coral and coral reef calcification.

Download or read book Coral Reefs in the Anthropocene written by Michael Sweet and published by Frontiers Media SA. This book was released on 2020-02-04 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: Every year, 10 outstanding Research Topics are selected as finalists of the Frontiers Spotlight Award. These shortlisted article collections each address a globally important field of research with the potential to drastically impact our future. They bring together the latest, cutting-edge research to advance their fields, present new solutions and foster essential, large-scale collaborations across multiple disciplines and research groups worldwide. This international research prize recognizes the most innovative and impactful topics and the winning team of editors receives $100,000 to organize an international scientific conference on the theme of their successful collection.

Download or read book New Isotopic Methods to Better Understand the Effects of Ocean Acidification on Net Ecosystem Calcification and Coral Calcification Rates in Bermuda written by Alyson Venti and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The health and future of coral and coral reef ecosystems remains threatened by global climate change (GCC) and ocean acidification (OA). There is a need to better understand the current health of coral reef ecosystems, particularly those in threshold environments which will likely be affected first by pressures from GCC and OA. This need can be addressed by answering two critical questions: 1) what are the current net ecosystem calcification (NEC) rates in threshold environments? And 2) what physical, biological or chemical parameter is/are driving these calcification rates? Bermuda, located at the northern threshold to support tropical coral reefs, provides an ideal study site to address these questions. To address the first question requires new methods to estimate reef water residence times, a parameter required for estimating NEC rates, but one that has traditionally been difficult to quantify with the necessary accuracy and precision. Two such methods are introduced here, one based on a radio chemical tracer (beryllium-7, 7Be) and one based on a stable chemical tracer ([delta]18O). Both 7Be and [delta]18O samples were measured from water samples collected on the Bermuda coral reef platform and yielded spatially and temporally integrated model residence times ranging between 1 and 10 days. To address the second question coral calcification rates were assessed simultaneously with physical (temperature, light) and chemical (seawater aragonite saturation states, [omega]arag) properties at both seasonal and hourly timescales to assess how calcification is affected by these physical and chemical driving factors. Seasonal differences in [omega]arag only explained a 2.4% change in coral growth, while seasonal differences in light and temperature explained 20% and 26% of the observed 81 mmolCaCO3 m-2 d-1 seasonal change in calcification rates of Porites astreoides and Diploria strigosa. This work contributes to the understanding impacts of GCC and OA on coral reef ecosystems by quantifying current NEC rates across the Bermuda coral reef platform, against which future rates can be assessed. This work also demonstrates that there are multiple driving factors affecting coral calcification rates in situ, though it does not suggest that OA may place a less influential role in governing future changes in coral growth rates as the expected change in [omega]arag for 2100 far exceeds the observed seasonal difference in this study.

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 Coral Reefs in the Anthropocene written by Charles Birkeland and published by Springer. This book was released on 2015-11-03 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume investigates the effects of human activities on coral reefs, which provide important life-supporting systems to surrounding natural and human communities. It examines the self-reinforcing ecological, economic and technological mechanisms that degrade coral reef ecosystems around the world. Topics include reefs and limestones in Earth history; the interactions between corals and their symbiotic algae; diseases of coral reef organisms; the complex triangle between reef fishes, seaweeds and corals; coral disturbance and recovery in a changing world. In addition, the authors take key recent advances in DNA studies into account which provides new insights into the population biology, patterns of species distributions, recent evolution and vulnerabilities to environmental stresses. These DNA analyses also provide new understandings of the limitations of coral responses and scales of management necessary to sustain coral reefs in their present states. Coral reefs have been essential sources of food, income and resources to humans for millennia. This book details the delicate balance that exists within these ecosystems at all scales, from geologic time to cellular interactions and explores how recent global and local changes influence this relationship. It will serve as an indispensable resource for all those interested in learning how human activities have affected this vital ecosystem around the world.

Download or read book Coral Reefs in the Anthropocene Ocean written by Nathaniel Rust Mollica and published by . This book was released on 2021 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anthropogenic emissions of greenhouse gases are driving rapid changes in ocean conditions. Shallow-water coral reefs are experiencing the brunt of these changes, including intensifying marine heatwaves (MHWs) and rapid ocean acidification (OA). Consequently, coral reefs are in broad-scale decline, threatening the livelihoods of hundreds of millions of people. Ensuring survival of coral reefs in the 21st century will thus require a new management approach that incorporates robust understanding of reef-scale climate change, the mechanisms by which these changes impact corals, and their potential for adaptation. In this thesis, I extract information from within coral skeletons to 1) Quantify the climate changes occurring on coral reefs and the effects on coral growth, 2) Identify differences in the sensitivity of coral reefs to these changes, and 3) Evaluate the adaptation potential of the keystone reef-building coral, Porites. First, I develop a mechanistic Porites growth model and reveal the physicochemical link between OA and skeletal formation. I show that the thickening (densification) of coral skeletal framework is most vulnerable to OA and that, under 21st century climate model projections, OA will reduce Porites skeletal density globally, with greatest impact in the Coral Triangle. Second, I develop an improved metric of thermal stress, and use a skeletal bleaching proxy to quantify coral responses to intensifying heatwaves in the central equatorial Pacific (CEP) since 1982. My work reveals a long history of bleaching in the CEP, and reef-specific differences in thermal tolerance linked to past heatwave exposure implying that, over time, reef communities have adapted to tolerate their unique thermal regimes. Third, I refine the Sr-U paleo-thermometer to enable monthly-resolved sea surface temperatures (SST) generation using laser ablation ICPMS. I show that laser Sr-U accurately captures CEP SST, including the frequency and amplitude of MHWs. Finally, I apply laser Sr-U to reconstruct the past 100 years of SST at Jarvis Island in the CEP, and evaluate my proxy record of bleaching severity in this context. I determine that Porites coral populations on Jarvis Island have not yet adapted to the pace of anthropogenic climate change.

Download or read book Coral Reefs in the Anthropocene written by Charles Birkeland and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume investigates the effects of human activities on coral reefs, which provide important life-supporting systems to surrounding natural and human communities. It examines the self-reinforcing ecological, economic, and technological mechanisms that degrade coral reef ecosystems around the world. Topics include reefs and limestones in Earth history; the interactions between corals and their symbiotic algae; diseases of coral reef organisms; the complex triangle between reef fishes, seaweeds, and corals; coral disturbance and recovery in a changing world. In addition, the authors take key recent advances in DNA studies into account which provides new insights into the population biology, patterns of species distributions, recent evolution, and vulnerabilities to environmental stresses. These DNA analyses also provide new understandings of the limitations of coral responses and scales of management necessary to sustain coral reefs in their present states. Coral reefs have been essential sources of food, income, and resources to humans for millennia. This book details the delicate balance that exists within these ecosystems at all scales, from geologic time to cellular interactions, and explores how recent global and local changes influence this relationship. It will serve as an indispensable resource for all those interested in learning how human activities have affected this vital ecosystem around the world.

Download or read book Coral Reefs at the Crossroads written by Dennis K. Hubbard and published by Springer. This book was released on 2016-07-27 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, contributors from diverse backgrounds take a first step toward an integrated view of reefs and the significance of their recent decline. More than any other earth system, coral reefs sit at a disciplinary crossroads. Most recently, they have reached another crossroads - fundamental changes in their bio-physical structure greater than those of previous centuries or even millennia. Effective strategies to mitigate recent trends will require an approach that embraces the myriad perspectives from across the scientific landscape, but will also need a mechanism to transform scientific understanding into social will and political implementation.

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 Global Climate Change and Coral Reefs written by Clive R. Wilkinson and published by World Conservation Union. This book was released on 1994 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: A global overview of the potential impacts of climate change and sea level rise on coral reefs, and of the implications of such impacts for ecological sustainable use of coral reefs. Includes information on the status and trends of reef conservation and use around the world, and suggestions for management of reefs in a changing world.

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.

Download or read book YOUMARES 9 the Oceans Our Research Our Future written by Simon Jungblut and published by Springer Nature. This book was released on 2020-01-01 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book summarizes peer-reviewed articles and the abstracts of oral and poster presentations given during the YOUMARES 9 conference which took place in Oldenburg, Germany, in September 2018. The aims of this book are to summarize state-of-the-art knowledge in marine sciences and to inspire scientists of all career stages in the development of further research. These conferences are organized by and for young marine researchers. Qualified early-career researchers, who moderated topical sessions during the conference, contributed literature reviews on specific topics within their research field. .

Download or read book Coral Reefs of the Western Pacific Ocean in a Changing Anthropocene written by Jing Zhang and published by Springer. This book was released on 2022-09-09 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The monograph is based on the research and training activities in the Western Pacific Ocean Region within the umbrella of UNESCO/IOC-Sub-Commission for the Western Pacific Region. The results of these activities are compared to cases from other tropical and subtropical regions on this planet to make the knowledge applicable to global aspects of sustainability of coral reef ecosystems. In this monograph, we examine the coral reefs from viewpoint of multidisciplinary approaches, including, environmental impacts, coral biology and system ecology, biogeochemical cycles and processes that drive the material and energy flow through the food web, as well as the proxies in geochemistry that have been used to track the responses of coral reefs to the changing climate and human perturbations. Although this study is focused on the Western Pacific Ocean, the Western Pacific Ocean is so large and diverse that most reef environment types on this planet are located within it. Therefore, knowledge gained in this study is relevant to the application of coastal management in practice as well as in the teaching classes on the interactions between coral reef ecosystems with changing environments.

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 2019-04-05 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 Coral Biomineralization Climate Proxies and the Sensitivity of Coral Reefs to CO2 driven Climate Change written by Thomas Mario DeCarlo and published by . This book was released on 2017 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scleractinian corals extract calcium (Ca2+) and carbonate (CO2−3) ions from seawater to construct their calcium carbonate (CaCO3) skeletons. Key to the coral biomineralization process is the active elevation of the CO2−3 concentration of the calcifying fluid to achieve rapid nucleation and growth of CaCO3 crystals. Coral skeletons contain valuable records of past climate variability and contribute to the formation of coral reefs. However, limitations in our understanding of coral biomineralization hinder the accuracy of (1) coral-based reconstructions of past climate, and (2) predictions of coral reef futures as anthropogenic CO2 emissions drive declines in seawater CO2−3 concentration. In this thesis, I investigate the mechanism of coral biomineralization and evaluate the sensitivity of coral reef CaCO3 production to seawater carbonate chemistry. First, I conducted abiogenic CaCO3 precipitation experiments that identified the U/Ca ratio as a proxy for fluid CO2−3 concentration. Based on these experimental results, I developed a quantitative coral biomineralization model that predicts temperature can be reconstructed from coral skeletons by combining Sr/Ca - which is sensitive to both temperature and CO2−3 - with U/Ca into a new proxy called “Sr-U”. I tested this prediction with 14 corals from the Pacific Ocean and the Red Sea spanning mean annual temperatures of 25.7-30.1°C and found that Sr-U has uncertainty of only 0.5°C, twice as accurate as conventional coral-based thermometers. Second, I investigated the processes that differentiate reef-water and open-ocean carbonate chemistry, and the sensitivity of ecosystem-scale calcification to these changes. On Dongsha Atoll in the northern South China Sea, metabolic activity of resident organisms elevates reef-water CO2−3 twice as high as the surrounding open ocean, driving rates of ecosystem calcification higher than any other coral reef studied to date. When high temperatures stressed the resident coral community, metabolic activity slowed, with dramatic effects on reef-water chemistry and ecosystem calcification. Overall, my thesis highlights how the modulation of CO2−3, by benthic communities on the reef and individual coral polyps in the colony, controls the sensitivity of coral reefs to future ocean acidification and influences the climate records contained in the skeleton.

Download or read book Coral Biomineralization Climate Proxies and the Sensitivity of Coral Reefs to CO2 driven Climate written by Thomas Mario DeCarlo and published by . This book was released on 2017 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scleractinian corals extract calcium (Ca2+) and carbonate (CO32−) ions from seawater to construct their calcium carbonate (CaCO3) skeletons. Key to the coral biomineralization process is the active elevation of the CO32− concentration of the calcifying fluid to achieve rapid nucleation and growth of CaCO3 crystals. Coral skeletons contain valuable records of past climate variability and contribute to the formation of coral reefs. However, limitations in our understanding of coral biomineralization hinder the accuracy of (1) coral-based reconstructions of past climate, and (2) predictions of coral reef futures as anthropogenic CO2 emissions drive declines in seawater CO32− concentration. In this thesis, I investigate the mechanism of coral biomineralization and evaluate the sensitivity of coral reef CaCO3 production to seawater carbonate chemistry. First, I conducted abiogenic CaCO32− precipitation experiments that identified the U/Ca ratio as a proxy for fluid CO32− concentration. Based on these experimental results, I developed a quantitative coral biomineralization model that predicts temperature can be reconstructed from coral skeletons by combining Sr/Ca - which is sensitive to both temperature and CO32− - with U/Ca into a new proxy called "Sr-U". I tested this prediction with 14 corals from the Pacific Ocean and the Red Sea spanning mean annual temperatures of 25.7-30.1 °C and found that Sr-U has uncertainty of only 0.5 °C, twice as accurate as conventional coral-based thermometers. Second, I investigated the processes that differentiate reef-water and open-ocean carbonate chemistry, and the sensitivity of ecosystem-scale calcification to these changes. On Dongsha Atoll in the northern South China Sea, metabolic activity of resident organisms elevates reef-water CO32− twice as high as the surrounding open ocean, driving rates of ecosystem calcification higher than any other coral reef studied to date. When high temperatures stressed the resident coral community, metabolic activity slowed, with dramatic effects on reef-water chemistry and ecosystem calcification. Overall, my thesis highlights how the modulation of CO32−, by benthic communities on the reef and individual coral polyps in the colony, controls the sensitivity of coral reefs to future ocean acidification and influences the climate records contained in the skeleton.

Download or read book Metabolic Ecology written by Richard M. Sibly and published by John Wiley & Sons. This book was released on 2012-04-30 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metabolic Ecology Most of ecology is about metabolism, the ways that organisms use energy and materials. The energy requirements of individuals (their metabolic rates) vary predictably with their body size and temperature. Ecological interactions are exchanges of energy and materials between organisms and their environments. Therefore, metabolic rate affects ecological processes at all levels: individuals, populations, communities and ecosystems. Each chapter focuses on a different process, level of organization, or kind of organism. It lays a conceptual foundation and presents empirical examples. Together, the chapters provide an integrated framework that holds the promise for a unified theory of ecology. The book is intended to be accessible to upper-level undergraduates and graduate students, but also of interest to senior scientists. Its easy-to-read chapters and clear illustrations can be used in lecture and seminar courses. This is an authoritative treatment that will inspire future generations to study metabolic ecology.