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 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 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 Coral Bleaching written by Madeleine J. H. van Oppen and published by Springer. This book was released on 2018-07-05 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most serious consequences of global climate change for coral reefs is the increased frequency and severity of mass coral bleaching events and, since the first edition of this volume was published in 2009, there have been additional mass coral bleaching events. This book provides comprehensive information on the causes and consequences of coral bleaching for coral reef ecosystems, from the genes and microbes involved in the bleaching response, to individual coral colonies and whole reef systems. It presents detailed analyses of how coral bleaching can be detected and quantified and reviews future scenarios based on modeling efforts and the potential mechanisms of acclimatisation and adaptation. It also briefly discusses emerging research areas that focus on the development of innovative interventions aiming to increase coral climate resilience and restore reefs.
Download or read book Coral Bleaching written by United States. Congress. Senate. National Ocean Policy Study and published by . This book was released on 1991 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 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 Ecophysiology and Biogeochemistry of Marine Plants in the Anthropocene written by Kasper Elgetti Brodersen and published by Frontiers Media SA. This book was released on 2022-09-29 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Assessing the Impacts of Ocean Acidification Global Warming and Terrestrial Runoff on the Cross shelf Variability of Coral Calcification in the Central Great Barrier Reef written by Juan Pablo D'Olivo Cordero and published by . This book was released on 2013 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ocean acidification and thermal stress due to anthropogenic greenhouse gas emissions present significant, potentially interacting, threats to the future of coral reefs. Coastal reef environments, as in the case of the Great Barrier Reef (GBR), can also be exposed to terrestrial stressors. This thesis evaluates the combined effects of ocean acidification, rising temperatures and river inputs on the calcification of Porites corals along a transect across-shelf the central GBR, north of Townsville. Calcification rates were obtained for 41 long-lived Porites corals from 7 reefs, in an inshore to offshore transect across the central GBR. The boron isotope composition (d11B) of selected cores was used to reconstruct annual and sub-annual changes in seawater pH in inner-shelf and mid-shelf environments. These unique seawater pH records are integrated with sea-surface temperature, river discharge and rainfall records to assess the nature and cause of seasonal, interannual, decadal and long-term (50 years) trends in coral calcification. Significant across-shelf differences in the temporal variability and long-term evolution of coral calcification are documented and can be related to local and global-scale changes in environmental conditions and water quality. Corals in the mid-shelf and outer-reef regions of the GBR exhibit an increase in calcification of 10.9% (1.1% S.E.) and 11.1% (3.9% S.E.) respectively since 1950 which are associated to the rise in sea-surface temperatures. However, calcification rates of mid-shelf corals show a decline of 3.3% (0.9% S.E.) over the recent period (1990-2008). This may indicate that a thermal optimum for calcification has been reached. Calcification rates in inner-shelf reefs over 1930-2008 display a long term trend of decreasing calcification of 4.6% (1.3% S.E.). The interannual-decadal component of variation is modulated by wet and dry periods, particularly during the last 40 years. The negative effects of bleaching on coral growth are evident in inshore reefs, and are particularly strong during 1998, with a significant recovery occurring after 3 years. This translate to constant calcification rates of 1.1% (2.0% S.E.) for the inner-shelf reefs over 1990-2008. These results highlight the need to consider regional differences in environmental factors when assessing and predicting changes in the GBR. Sub-annual and annual variation in the d11B of inner-shelf corals record seasonal and interannual seawater pH changes of up to 0.5 pH units. This variability is overlain on a long-term decrease of 0.02 pH units per decade, consistent with estimates of surface seawater acidification due to rising atmosphere CO2 levels. Sub-annual low pH values occur in summer and partly reflect the effects of higher temperatures and increased calcification (a source of CO2). Higher d11B (pH) values are observed in wet years when nutrients supplied by river run-off promote extensive phytoplankton blooms that take up CO2 and increase seawater pH. Decreased calcification of inner-shelf corals during large flood events, despite higher pH conditions, may reflect increased shading, turbidity, sedimentation and/or competition for carbon. The complex interactions between processes that can affect coral calcification, particularly in coastal zones, need to be considered when predicting the future of coral reefs in warmer and more acidic oceans.
Download or read book Understanding Individual and Combined Effects of Ocean Acidification Warming and Coastal Runoff on Marine Calcifying Organisms on Tropical Coral Reefs written by and published by . This book was released on 2015 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Ocean Acidification on the Physiology of Coral Recruits written by Aaron Matthew Dufault and published by . This book was released on 2012 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ocean acidification (OA), caused by the dissolution of anthropogenic CO2 into the surface waters of the ocean, threatens the fate of calcifying marine organisms. The effects of OA on adult coral calcification have been well-studied over the past decade and generally results in decreased calcification rates with increasing pCO2, although the effects of OA on early life history stages are less well-studied. This thesis addresses the effects of OA on coral recruit physiology with an emphasis on filling key gaps in the ecological relevance of previous manipulative OA coral studies. Together the findings provide novel insight into the physiology of corals exposed to OA under ecologically relevant seawater chemistry and light conditions. Coral recruits are biologically quite different than their adult counterparts therefore further work is needed to determine the extent to which these results apply to adult corals.
Download or read book Physiological Adaptations in Hawaiian Corals to Global Climate Change written by Rowan H. McLachlan and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The distribution and abundance of coral reef ecosystems is declining globally due to the detrimental impacts of climate change. As the surface ocean becomes warmer and more acidic, corals must adapt or acclimatize in order to survive and persist. The overarching goal of my dissertation was to evaluate the biological processes that lead corals to adapt and acclimatize to the levels of ocean warming and acidification expected later this century. Following a review of 255 coral heat-stress experiments conducted over the last thirty years (Chapter 2), I identified several gaps in our knowledge of coral bleaching. For instance, the majority of experimental coral bleaching research has been conducted on only three Scleractinian coral species, many reef regions worldwide are critically understudied, and the literature is heavily biased towards adult life stages (as opposed to gametes, larvae, recruits). Similarly, the majority of studies are short-term in duration (i.e.,
Download or read book Effects of Ocean Acidification and Temperature on the Physiology of Juvenile Scleractinian Corals written by Christopher Wall and published by . This book was released on 2013 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
