Download or read book Plastic Versus Fixed Influences on Coral Response to Fluctuating Environmental Conditions written by Daniel J. Barshis and published by . This book was released on 2009 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: The degree to which coral reef ecosystems will be impacted by global climate change depends on regional and local differences in corals' susceptibility and resilience to environmental stressors. This dissertation attempts to investigate the physiological basis behind the unique stress tolerance of a group of back reef corals that experience daily environmental extremes thought to cause bleaching and mortality in most corals. I examined the response of a suite of stress protein biomarkers in the common reef coral Pontes lobata from multiple back reef sites and a neighboring forereef on Ofu and Olosega Islands, American Samoa, using field reciprocal transplant experiments (RTEs) and controlled laboratory manipulations. Additionally, I examined the genetic diversity of P. lobata hosts and their algal symbionts in both back reef and forereef populations to assess the degree of gene-flow between areas and the influence of symbiont genotype on coral response. RTEs performed during the southern summer revealed a combination of both fixed and environmental influence on biomarker response. Fixed influences were strongest for ubiquitin-conjugated proteins with consistently higher levels found in back reef versus forereef source colonies both pre and post transplant; suggesting a greater amount of or capacity to process irreversible protein denaturation in back reef corals. Algal endosymbiont populations were genetically indistinguishable between the forereef and back reef sites based on nuclear ribosomal DNA, while genetic analyses of nuclear microsatellite and mitochondrial loci of the coral host revealed both large scale (100 km) and small scale (1 km) population subdivision. Fixed and environmental influences on biomarker responses were consistent over seasonal and long-term changes, with a significant reduction in ubiquitin-conjugates during winter versus summer seasons when daily extremes in back reef characteristics were lowest. Controlled acclimation experiments demonstrated that coral thermal tolerance increased following exposure to fluctuating versus stable temperatures, although back reef corals still exhibited elevated thermal tolerance compared to forereef corals despite acclimation treatments. These experiments demonstrate that exposure to environmental variability promotes coral stress tolerance at both the level of phenotypic plasticity as well as over longer time-scales through epigenetic changes to or evolutionary adaptation of the coral stress response.
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 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 Plastic and Genetic Responses to Environmental Changes written by David Springate and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Human activity is causing climates to change more rapidly than at any time in the last 10,000 years. If populations of organisms are unable to effectively respond to changing environments, they will be at risk of extinction. In plants, two of the most important mechanisms of response to environmental change are phenotypic plasticity, where the same genotype expresses different phenotypes in different environments, and adaptation, which requires changes in allele frequency in populations as exposed individuals show variable survival and reproduction. Although most researchers accept the importance of both of these mechanisms, they are most commonly considered in isolation in models of response and persistence to climate change. Here, I use the model species Arabidopsis thaliana to investigate the interaction of plasticity and selection in fitness and phenology response to simulated climate warming, the effect of artificial selection on variation for plastic response and cross-generational effects of environmentally induced variation in flowering time. I also study the effects of varying rates of environmental fluctuation on evolvability on populations of self-replicating computer programs using the artificial life platform Avida. I find that a small increase in ambient temperature, in line with predictions for the next few decades, is able to elicit significant plastic responses and that these responses have the potential to alter population genetic structure and affect future evolution. I also find that selection on flowering time can reduce variation for plastic response and that non-genetic effects on flowering time can significantly alter germination in the next generation. Lastly, I find that rapidly changing environments in the long term can select for more evolvable populations and genotypes. These results highlight the importance of considering plasticity and evolution together if we are going to make accurate predictions of climate change response.
Download or read book Changing Plankton Communities Causes Effects and Consequences written by Kristian Spilling and published by Frontiers Media SA. This book was released on 2019-10-04 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine ecosystems are changing at an unprecedented rate. In addition to the direct effects of e.g. warming surface temperatures, the environmental changes also cause shifts in plankton communities. Plankton makes up the base of the marine food web and plays a pivotal role in global biogeochemical cycles. Any shifts in the plankton community composition could have drastic consequences for marine ecosystem functioning. This Research Topic focuses on causes, effects and consequences of such shifts in the plankton community structure.
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 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 Biology of Damselfishes written by Bruno Frédérich and published by CRC Press. This book was released on 2016-08-19 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: Damselfishes (Pomacentridae) are highly conspicuous, diurnal inhabitants of mainly reef areas, capturing the attention of many scientists. Their high diversity and the many interesting characteristics dealing with their way of life (sound production, breeding biology, sex change, farming and gregarious behavior, settlement, diet, habitat) easily explain how this group is continually kept in the limelight and is the subject of numerous studies. This book gathers the data dealing with damselfish morphology, physiology, behavior, ecology and phylogeny.It contains 14 chapters written by renowned scientists.
Download or read book Fluctuating Reef Environments Maintain Coral Resilience written by Lance W. Smith and published by . This book was released on 2008 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: The shallow back reef pools on Ofu Island, American Samoa, are highly-fluctuating environments where seawater temperature and irradiance often reach levels thought to cause bleaching of reef-building corals, yet bleaching is rare in the pools. I hypothesized that environmental fluctuations associated with the pools, and biological mechanisms associated with back reef host corals and their algal endosymbionts, both reduce the effects of elevated seawater temperatures and high irradiance levels. I tested the hypotheses with a series of water table and field experiments. Water table experiments using Porites lobata and P. cylindrica suggested that intermittent flow associated with semi-diurnal tides, and low irradiances caused by turbidity or shading, reduce photoinhibition and bleaching of back reef corals during warming events. Reciprocal transplant experiments (RTEs) of the corals P. lobata and Pocillopora eydouxi between the highly-fluctuating back reef pools and a nearby environmentally consistent forereef site demonstrated that back reef colonies of both species survived better and grew more than their forereef counterparts regardless of transplant site. For P. lobata, growth was more affected by source population than transplant site, suggesting effects of either developmental phenotypic plasticity or genetic polymorphism. For P. eydouxi, growth was only affected by transplant site, demonstrating effects of physiological phenotypic plasticity. In addition, a survey of zooxanthella genotypes of P. lobata, P. eydouxi, Galaxea fascicularis, and Acropora gemmifera colonies at the back reef and forereef sites used for the RTEs showed a higher proportion of heat-resistant Clade D genotypes in back reef colonies of all four coral species except P. lobata. In conclusion, these experiments demonstrated that environmental characteristics and biological mechanisms associated with fluctuating reef environments and their corals maintain the resilience of coral populations to disturbances for three reasons. First, potentially stressful conditions (elevated seawater temperatures and high irradiance levels) are moderated by environmental characteristics such as semi-diurnally intermittent flow. Second, exposure to these conditions likely maintains selection for mechanisms of acclimatization (phenotypic plasticity) or adaptation (genetic polymorphism) within host coral populations. Third, exposure of coral colonies to diurnally and seasonally fluctuating conditions maintains zooxanthella genotype diversity in some host coral species.
Download or read book The Great Barrier Reef written by Pat Hutchings and published by CSIRO PUBLISHING. This book was released on 2008-11-07 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Great Barrier Reef Marine Park is 344 400 square kilometres in size and is home to one of the most diverse ecosystems in the world. This comprehensive guide describes the organisms and ecosystems of the Great Barrier Reef, as well as the biological, chemical and physical processes that influence them. Contemporary pressing issues such as climate change, coral bleaching, coral disease and the challenges of coral reef fisheries are also discussed. In addition,the book includes a field guide that will help people to identify the common animals and plants on the reef, then to delve into the book to learn more about the roles the biota play. Beautifully illustrated and with contributions from 33 international experts, The Great Barrier Reef is a must-read for the interested reef tourist, student, researcher and environmental manager. While it has an Australian focus, it can equally be used as a baseline text for most Indo-Pacific coral reefs. Winner of a Whitley Certificate of Commendation for 2009.
Download or read book Eco evolutionary Dynamics written by Andrew P. Hendry and published by Princeton University Press. This book was released on 2020-06-09 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, scientists have realized that evolution can occur on timescales much shorter than the 'long lapse of ages' emphasized by Darwin - in fact, evolutionary change is occurring all around us all the time. This work provides an authoritative and accessible introduction to eco-evolutionary dynamics, a cutting-edge new field that seeks to unify evolution and ecology into a common conceptual framework focusing on rapid and dynamic environmental and evolutionary change.
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 Effects of Environment and Life History Strategy on Coral Reproductive Success written by Aaron C. Hartmann and published by . This book was released on 2014 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral reefs are threatened worldwide due to anthropogenic activities resulting in the loss of these ecosystems at an alarming rate. In this dissertation I build upon fundamental ecological theory related to early life history characters in order to identify factors affecting coral reproductive success in response to environmental change. I found that apparently healthy corals on degraded reefs contained lower energetic lipid content than conspecifics on healthy reefs within the island of Curacao, which contains some of the Caribbean's healthiest coral reefs. This work also revealed that populations differed in the number of offspring produced, highlighting reef-specific differences in reproductive potential. Motivated by observed variation in offspring size within and among species, I found that large size enhanced larval survival, yet unexpectedly did not afford larvae greater tolerance of harsh environmental conditions. Surprisingly, a species that produces large larvae and tolerates marginal environmental conditions as adults was particularly sensitive to environmental stress during the larval stage. I concluded that this difference arose due to the presence of symbiotic algae in larvae of this species. I subsequently determined that the uptake of symbionts during the larval stage led to disadvantageous behaviors and gene expression patterns. Furthermore, symbionts did not provide energy to larvae, as they do in adults. These results led me to theorize that the timing of symbiont acquisition is most optimal when it occurs around the time larvae locate cues for metamorphosing into an adult body form. To substantiate my theory in an evolutionary context, I performed a character trait reconstruction with the known phylogeny of reef corals. Evolutionary transition rates differed depending on whether a species transfers symbionts directly to larvae or obtains them from the environment. The loss of direct transmission correlated with transitions from high to low bleaching susceptibility in adult corals, suggesting a previously unknown evolutionary transition that favors environmental tolerance. In summary, my work contributes to general understanding of how larval characters and early life history strategies affect survival and fitness in corals, and offers insights into the ecological and evolutionary mechanisms by which larval corals respond to human-induced environmental change.
Download or read book Components of a Flexible Phenotype in Two Species of Scleractinian Coral Under Ocean Acidification written by Jessica Lauren Bergman and published by . This book was released on 2017 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: A developmental reaction norm integrates three tightly linked factors of ontogeny, genotype, and environment to address the ability of an organism to deal with environmental change. This concept of organismic flexibility is termed plasticity, and is well characterized in coral reef systems. However, there has been little quantification of how phenotypic plasticity in scleractinian corals may modulate their response to ocean acidification. This thesis consists of two studies addressing the role of ontogeny, genotype, and environment as influences on phenotypic complexity in scleractinian corals that may affect their response to ocean acidification. In Chapter 2, to address ontogeny, I investigated the effects of elevated pCO2 on the movement and behavior of brooded Pocillopora damicornis larvae in Okinawa, Japan, in 2016. A change in behavior in this developmental stage may alter distribution and settlement patterns of adult colonies of P. damicornis. I found that brooded larvae freshly released from P. damicornis are able to regulate their vertical position in the seawater over at least 12 h, and that this response, likely driven by a combination of modified buoyancy and active swimming, is affected by high pCO2. A change in vertical position of larvae due to elevated pCO2 has the potential to mediate pelagic larval duration (PLD) by determining their exposure to differing horizontal strata of water, thereby mediating the extent of larval connectivity among populations. In Chapter 3, to address genotype and environment, I first observed the effect of genotype-specific variation within adult colonies of P. damicornis in their growth response to elevated pCO2 in Moorea, French Polynesia, in 2016. In this preliminary experiment, I found differences among genotypes in mean growth rate that varied among trials conducted in different months, likely due to the environmental history of the corals. To quantify plasticity in two different environments, I conducted an experiment in 2017 that investigated how a plastic response in a coral to an environment change might modulate success in a fitness trait under elevated pCO2. I quantified plasticity using a suite of morphological traits in Pocillopora verrucosa at two different depths, and measured growth of plastic genotypes in high pCO2. Results suggest that genotype-specific morphological plasticity does not influence success in growth in high pCO2. Overall, the goal of this thesis was to better understand the scope of a coral's ability to deal with environmental heterogeneity (e.g. increasing ocean acidity) based on the formation and flexibility of its phenotype. Results indicate that under projected ocean acidification conditions, the formation of a coral's phenotype (e.g. larval behavior) will be affected by high pCO2, but that a flexible phenotype in adult corals does not appear to modulate growth success in high pCO2.
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 Managing Ocean Environments in a Changing Climate written by Kevin J. Noone and published by Newnes. This book was released on 2013-06-29 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Managing Ocean Environments in a Changing Climate summarizes the current state of several threats to the global oceans. What distinguishes this book most from previous works is that this book begins with a holistic, global-scale focus for the first several chapters and then provides an example of how this approach can be applied on a regional scale, for the Pacific region. Previous works usually have compiled local studies, which are essentially impossible to properly integrate to the global scale. The editors have engaged leading scientists in a number of areas, such as fisheries and marine ecosystems, ocean chemistry, marine biogeochemical cycling, oceans and climate change, and economics, to examine the threats to the oceans both individually and collectively, provide gross estimates of the economic and societal impacts of these threats, and deliver high-level recommendations. Nominated for a Katerva Award in 2012 in the Economy category State of the science reviews by known marine experts provide a concise, readable presentation written at a level for managers and students Links environmental and economic aspects of ocean threats and provides an economic analysis of action versus inaction Provides recommendations for stakeholders to help stimulate the development of policies that would help move toward sustainable use of marine resources and services
Download or read book The Ocean and Cryosphere in a Changing Climate written by Intergovernmental Panel on Climate Change (IPCC) and published by Cambridge University Press. This book was released on 2022-04-30 with total page 755 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for assessing the science related to climate change. It provides policymakers with regular assessments of the scientific basis of human-induced climate change, its impacts and future risks, and options for adaptation and mitigation. This IPCC Special Report on the Ocean and Cryosphere in a Changing Climate is the most comprehensive and up-to-date assessment of the observed and projected changes to the ocean and cryosphere and their associated impacts and risks, with a focus on resilience, risk management response options, and adaptation measures, considering both their potential and limitations. It brings together knowledge on physical and biogeochemical changes, the interplay with ecosystem changes, and the implications for human communities. It serves policymakers, decision makers, stakeholders, and all interested parties with unbiased, up-to-date, policy-relevant information. This title is also available as Open Access on Cambridge Core.
