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Century Scale Records Of Coral Growth And Water Quality From The Mesoamerican Reef Reveal Increasing Anthropogenic Stress And Decreasing Coral Resilience
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Book Synopsis Century-scale Records of Coral Growth and Water Quality from the Mesoamerican Reef Reveal Increasing Anthropogenic Stress and Decreasing Coral Resilience by : Jessica Elizabeth Carilli
Download or read book Century-scale Records of Coral Growth and Water Quality from the Mesoamerican Reef Reveal Increasing Anthropogenic Stress and Decreasing Coral Resilience written by Jessica Elizabeth Carilli and published by . This book was released on 2009 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :National Academies of Sciences, Engineering, and Medicine Publisher :National Academies Press ISBN 13 :030948538X Total Pages :259 pages Book Rating :4.3/5 (94 download)
Book Synopsis A Research Review of Interventions to Increase the Persistence and Resilience of Coral Reefs by : National Academies of Sciences, Engineering, and Medicine
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.
Author :National Academies of Sciences, Engineering, and Medicine Publisher :National Academies Press ISBN 13 :0309485355 Total Pages :259 pages Book Rating :4.3/5 (94 download)
Book Synopsis A Research Review of Interventions to Increase the Persistence and Resilience of Coral Reefs by : National Academies of Sciences, Engineering, and Medicine
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.
Book Synopsis A Reef Manager's Guide to Coral Bleaching by :
Download or read book A Reef Manager's Guide to Coral Bleaching written by and published by . This book was released on 2006 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explores emerging monitoring strategies and presents adaptive management techniques to anticipate and mitigate coral bleaching, with emphasis upon identification and promotion of resilience in coral reef ecosystems. Includes coverage of strategic use of marine protected areas.
Book Synopsis The Mexican Caribbean Reefs by : Ameris Ixchel Contreras Silva
Download or read book The Mexican Caribbean Reefs written by Ameris Ixchel Contreras Silva and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Mexican Caribbean is home to many coral reefs with a high ecological and economic value for people in the country and beyond. Nevertheless, these ecosystems are highly threatened due to a combination of global (anthropogenic climate change) and local stressors (mass tourism, land-based pollution, and overuse of resources). The decline of the wider Caribbean coral reefs has been alarming, with an average loss of 40 percent of absolute coral cover since the late 1970s. However, the current literature lacks spatiotemporal information on the coral and macroalgae cover development and longitudinal studios regarding the stressors causing changes in Mexican Caribbean reefs. Therefore, this thesis aimed first to understand the benthic dynamics of change and the main stressors causing these changes to finally propose a conceptual framework to improve coral reef management. A large-scale spatiotemporal analysis between 1978 and 2016 on coral and macroalgae cover in the Mexican Caribbean reefs was conducted through meta-analysis. Here, findings revealed that hard coral cover decreased from ~ 26 % in the 1970s to 16 % in 2016, whereas macroalgae cover increased from ~ 16 % in the 1980s to ~ 30 % in 2016. Both groups showed high spatiotemporal variability. Hard coral cover declined by 12 % from 1978 to 2004 but increased again by 5 % between 2005 and 2016, indicating some coral recovery after the 2005 mass bleaching event and hurricane impacts. Additionally, a cumulative impact assessment on hard coral and macroalgae benthic communities exposed to multiple stressors (thermal stress, nutrient inflow, sedimentation, hurricane impact, and anthropisation) was conducted using an extensive remote sensing data collection. These data were coupled with 91 coral reef monitoring sites from 2005 to 2016, and the estimates of the change in coral and macroalgae cover percentage were related to each factor considered a potential stressor impacting reefs. Results showed that sea surface temperature increased by 0.30 °C in 12 years, and bleaching susceptibility strongly influenced coral cover change, followed by the negative effect of anthropogenic activities, which incorporates the increasing pressures of urban hubs. The water quality predictors, primarily the particulate organic carbon (used as a proxy for sedimentation and nutrients), only affected macroalgae cover. The only adverse effect on macroalgae was sea surface temperature and chlorophyll-a interaction. Analyses here revealed that global warming impacts on coral reefs occur parallel with local pressures, such as increases in nutrients and suspended sediments through coastal development. The future of Mexican Caribbean coral reefs is at high risk due to cumulative impacts from local and global stressors despite monitoring and restoration efforts over the past few decades, which begs the question of why and how protection and management may be improved. Consequently, a conceptual framework was generated focusing on an integrated management strategy to improve the understanding of the unique and vital services that coral reef ecosystems in the Mexican Caribbean provide. Within this spectrum, a Cybercartographic atlas was proposed because it offers an excellent method for creating a conceptual framework for such a management tool. The ultimate objective is to make arguments accessible that serve as a baseline for assisting and setting priorities for governance in political decisions.
Book Synopsis Coral Reefs in the Anthropocene Ocean by : Nathaniel Rust Mollica
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.
Book Synopsis Holocene Coral Reef Development in the Tropical Eastern Pacific by : Lauren Trent Toth
Download or read book Holocene Coral Reef Development in the Tropical Eastern Pacific written by Lauren Trent Toth and published by . This book was released on 2013 with total page 804 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent decades, a variety of local- to global-scale disturbances have caused the global degradation of coral-reef ecosystems. In most regions, large-scale coral mortality is a recent phenomenon. In contrast, my records from the tropical eastern Pacific (TEP) have revealed a period of limited coral-reef development, beginning about 4000 cal BP (calibrated calendar years before 1950), which lasted for the next 2500 years. This protracted hiatus in reef growth provides the opportunity to test explicit predictions about the causes of reef collapse, the controls on reef resilience, and the likely trajectories of reef development in the future. Reefs of the TEP are subject to a variety of modern environmental stressors, the most important of which are seasonal upwelling and interannual impacts of the El Niño-Southern Oscillation (ENSO); however, the relative roles of these stressors in shaping past reef development are unknown. Although it is generally accepted that reef growth in the TEP is slow compared with other regions around the world, this assumption has never been tested, and the paleoecological record from reefs in this region is limited. Using data from cores of reef frameworks collected throughout Pacific Panamá, this study evaluated trends in reef development from ~7000 cal BP to the present to assess the impacts of environmental variability on reef growth during the Holocene. To further characterize the observed hiatus in reef growth and investigate the impact of seasonal upwelling on past reef development, I compared trends in vertical reef accretion among three sites situated along a contemporary gradient of seasonal upwellling: Contadora Island, which received the most intense seasonal upwelling; Iguana Island, where upwelling was moderate; and Canales de Tierra Island, where there was no upwelling. By reconstructing the age of the local radiocarbon reservoir for each of these sites, I confirmed that this general upwelling regime existed from at least ~7000 cal BP to the present. I also used geochemical analyses of fossil coral skeletons and reef sediments from Contadora to reconstruct the regional climatic and oceanographic conditions over the last 7000 years and evaluated their impacts on coral condition. Coral reefs at all three sites stopped growing from ~4100-1600 cal BP, coincident with the shutdown of reef development at several other locations elsewhere in the Pacific. There was a dramatic and significant reduction in reef accretion during the depositional hiatus. Contrary to earlier surmises that reef growth was slow in the TEP, however, millennial rates of reef accretion in Pacific Panama ́before and after the hiatus were similar to those documented in the Caribbean region. There was no significant difference in reef accretion among sites, which suggests that although upwelling has an impact on the short-term growth of corals, upwelling does not impact long-term reef accretion. Upwelling did, however, have a significant impact on the duration of reef collapse. The hiatus in reef accretion began earlier, ended later and, therefore, lasted significantly longer at Contadora, where reefs are subject to the strongest seasonal upwelling. Although upwelling was most likely not the ultimate cause of the hiatus, persistent upwelling may reduce the capacity of a reef to recover from major disturbances. Correlative evidence from regional paleoclimate proxies suggested that the ultimate cause of the hiatus was most likely enhanced climatic oscillations, particularly variability associated with ENSO. In the TEP, El Niño and La Niña events result in dramatic changes in sea temperatures, nutrient inputs, turbidity, and sea level, all of which can be problematic for reef development. ENSO activity increased 4500-4000 cal BP, coincident with the onset of the hiatus. Additionally, ENSO variability was likely enhanced from 4000-2000 cal BP due to it becoming in-phase, or "coupled", with the Intertropical Convergence Zone (ITCZ). Overall, hiatus was a time of stronger and more frequent El Niño and La Niña events and this period of enhanced climatic variability likely overwhelmed the capacity of reefs to recover. Reef growth resumed when there was a change in the mode of ENSO, with more El Niño events, but fewer La Niña events after ~2000 cal BP. Climatic reconstructions from this study suggested that oceanic productivity at Contadora was higher in the mid-Holocene, 6000-4000 cal BP, likely as a result of increased upwelling, compared with the period 4000-2000 cal BP. These results supports the conclusion of other researchers that the early to middle Holocene, may have been more "La Niña-like", compared with the late Holocene, when mean climate had shifted to a more "El Niño-like" state. Furthermore, my environmental reconstructions before and after the hiatus in reef accretion reveal that climatic and oceanographic variability in the TEP were greater over centennial scales than previously surmised. From 5000-4500 cal BP, conditions were warmer and drier, and there was less upwelling, than at other times in the Holocene. Oceanic productivity and climatic variability both increased in the 100-200 yr preceding the shutdown of reef growth. These changes are consistent with the hypothesis of escalating ENSO variability overall, and in particular an increase in La Niña activity. I used coral [lower case delta]13C, a measure of productivity and coral health, and B/Ca, a measure of carbonate saturation state within the coral, to track changes in coral condition through time. Dramatic declines in both coral productivity and coral saturation state occurred just before the hiatus, indicating that sublethal declines in coral health could serve as early warning signs of ecosystem collapse. Although coral productivity was high just after the hiatus, it gradually declined over the period ~1500 cal BP to present. One explanation for the deteriorating health of corals during this interval was that the increase in the number of El Niño events through the late Holocene resulted in an increasing frequency and severity of coral bleaching events. The parallel between the reduction in coral productivity before the collapse of Panamanian reefs ~4100 cal BP and the slow decline of coral productivity through the late Holocene may indicate that reefs in the TEP are headed toward another significant interruption in reef development in the future. There is no clear consensus on how anthropogenic climate change will affect ENSO in the future; however, many of the same conditions that occurred during the hiatus are also expected under reasonable scenarios of future climate change. If the history of reef development in Pacific Panamá is any indication of what may happen in the future, climate change could indeed be pushing some Pacific reefs towards another major collapse. On the other hand, these reefs were able to recover after a 2500-yr hiatus in reef development. Thus, if the current trajectories of climate change can be reversed, there may yet be hope for the reefs of the future.
Book Synopsis 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 by : Juan Pablo D'Olivo Cordero
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.
Book Synopsis Quaternary Coral Reef Systems by : Lucien F. Montaggioni
Download or read book Quaternary Coral Reef Systems written by Lucien F. Montaggioni and published by Elsevier. This book was released on 2009-08-13 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents both state-of-the art knowledge from Recent coral reefs (1.8 million to a few centuries old) gained since the eighties, and introduces geologists, oceanographers and environmentalists to sedimentological and paleoecological studies of an ecosystem encompassing some of the world's richest biodiversity. Scleractinian reefs first appeared about 300 million years ago. Today coral reef systems provide some of the most sensitive gauges of environmental change, expressing the complex interplay of chemical, physical, geological and biological factors. The topics covered will include the evolutionary history of reef systems and some of the main reef builders since the Cenozoic, the effects of biological and environmental forces on the zonation of reef systems and the distribution of reef organisms and on reef community dynamics through time, changes in the geometry, anatomy and stratigraphy of reef bodies and systems in relation to changes in sea level and tectonics, the distribution patterns of sedimentary (framework or detrital) facies in relation to those of biological communities, the modes and rates of reef accretion (progradation, aggradation versus backstepping; coral growth versus reef growth), the hydrodynamic forces controlling water circulation through reef structures and their relationship to early diagenetic processes, the major diagenetic processes affecting reef bodies through time (replacement and diddolution, dolomitization, phosphatogenesis), and the record of climate change by both individual coral colonies and reef systems over the Quaternary. * state-of-the-art knowledge from Recent corals reefs* introduction to sedimentological and paleoecological studies of an ecosystems encompassing some of the world's richest biodiversity.* authors are internationally regarded authorities on the subject* trustworthy information
Book Synopsis Marine Animal Forests by : Sergio Rossi
Download or read book Marine Animal Forests written by Sergio Rossi and published by Springer. This book was released on 2017-08-15 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last decades there has been an increasing evidence of drastic changes in marine ecosystems due to human-induced impacts, especially on benthic ecosystems. The so called “animal forests” are currently showing a dramatic loss of biomass and biodiversity all over the world. These communities are dominated by sessile suspension feeder organisms (such as sponges, corals, gorgonians, bivalves, etc.) that generate three-dimensional structures, similar to the trees in the terrestrial forest. The animal forest provide several ecosystem services such as food, protection and nursery to the associated fauna, playing an important role in the local hydrodynamic and biogeochemical cycles near the sea floor and acting also as carbon sinks. The present book focus its attention on these three dimensional animal structures including, for the first time, all the different types of animal forests of the world in a single volume.
Book Synopsis The Coral Reef Era: From Discovery to Decline by : James Bowen
Download or read book The Coral Reef Era: From Discovery to Decline written by James Bowen and published by Springer. This book was released on 2015-01-06 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: On 4 June 1629, the Batavia, pride of the Dutch East India Company Fleet, was wrecked on her maiden voyage in a seemingly empty expanse of the Indian Ocean. The question “how did this happen?” led to 300 years of investigation by those curious to solve the enigma: what are corals and how are coral reefs formed?. Relying heavily on primary source material Part 1 traces the sequential evolution of scientific thought and practice as the author explores the way this evolution is reflected in the search for understanding corals. At each stage, answers lead to fresh questions that challenge investigators to solve the riddle and new branches of science emerge. Then, with the first enigma finally understood, a new enigma arose. Why are Reefs dying? Part 2 traces the range of problems that have emerged in the past 50 years as marine, ecological, reef and climate scientists attempt to put the pieces of the jigsaw together. Is there a new “canary in the coal mine” warning of the fate of the world as we know it if man’s impact on his environment continues unchecked?.
Book Synopsis Reefs at Risk Revisited by : Lauretta Marie Burke
Download or read book Reefs at Risk Revisited written by Lauretta Marie Burke and published by . This book was released on 2011 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Latin American Coral Reefs by : J. Cortés
Download or read book Latin American Coral Reefs written by J. Cortés and published by Elsevier. This book was released on 2003-04-25 with total page 509 pages. Available in PDF, EPUB and Kindle. Book excerpt: Approx.508 pages
Book Synopsis Natural Vs. Anthropogenic Sedimentation by : Francesca Fourney
Download or read book Natural Vs. Anthropogenic Sedimentation written by Francesca Fourney and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Corals face serious worldwide population declines due to global climate change in combination with direct anthropogenic impacts. Global climate change is difficult to manage locally, but policy makers can regulate the magnitude of local stressors affecting reefs. The objective of this experiment is to investigate if reducing sedimentation will enable reef corals to better endure global climate change. It has been shown that some coral species can handle climate change stress when provided with additional energy resources. Here I tested if the capacity of corals to cope with climate change can be improved when their ability to feed and photosynthesize was not compromised by increased sedimentation. Sedimentation can impede coral feeding and their ability to photosynthesize due to direct polyp blocking and increased turbidity, which reduces light availability. To evaluate the potential of enhancing coral ability to tolerate climate change by reducing a local stressor, I examined the survival and growth of brooding coral Porites astreoides juveniles when exposed to ambient and elevated water temperatures under differing sedimentation rates. I also assessed if sediment composition has significant impacts on these results. I used sediment from a reef and sediment from a boat basin within a port to mimic natural and anthropogenic sediment types and processes (e.g. dredging). Experiments were conducted to quantitatively assess the synergistic effects of sediment concentration and composition, along with increased temperature on the survival and growth of juvenile P. astreoides. The most detrimental effects were observed with anthropogenic sediment, when both sediment concentration and water temperatures were high. However, increased natural reef sediment was found to be beneficial to juvenile corals. More interestingly, I found that corals capacity to deal with higher temperatures is improved when anthropogenic sedimentation is maintained at minimal levels and turbidity resulting from sedimentation was low. Therefore, this information will aid managers in making decisions that regulate dredging and construction activities to minimize sedimentation, which will contribute to increase coral survival under climate change.
Book Synopsis Global Climate Change and Coral Reefs by : Clive R. Wilkinson
Download or read book Global Climate Change and Coral Reefs written by Clive R. Wilkinson and published by IUCN. This book was released on 1994 with total page 140 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.
Book Synopsis Global Trends 2040 by : National Intelligence Council
Download or read book Global Trends 2040 written by National Intelligence Council and published by Cosimo Reports. This book was released on 2021-03 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The ongoing COVID-19 pandemic marks the most significant, singular global disruption since World War II, with health, economic, political, and security implications that will ripple for years to come." -Global Trends 2040 (2021) Global Trends 2040-A More Contested World (2021), released by the US National Intelligence Council, is the latest report in its series of reports starting in 1997 about megatrends and the world's future. This report, strongly influenced by the COVID-19 pandemic, paints a bleak picture of the future and describes a contested, fragmented and turbulent world. It specifically discusses the four main trends that will shape tomorrow's world: - Demographics-by 2040, 1.4 billion people will be added mostly in Africa and South Asia. - Economics-increased government debt and concentrated economic power will escalate problems for the poor and middleclass. - Climate-a hotter world will increase water, food, and health insecurity. - Technology-the emergence of new technologies could both solve and cause problems for human life. Students of trends, policymakers, entrepreneurs, academics, journalists and anyone eager for a glimpse into the next decades, will find this report, with colored graphs, essential reading.
Book Synopsis Independent and Interacting Effects of Multiple Anthropogenic Stressors on Cold-Water Corals by : Alexis Weinnig
Download or read book Independent and Interacting Effects of Multiple Anthropogenic Stressors on Cold-Water Corals written by Alexis Weinnig and published by . This book was released on 2020 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: Human population growth and global industrial development are driving potentially irreversible anthropogenic impacts on the natural world, including altering global climate and ocean conditions and exposing oceanic environments to a wide range of pollutants. While there are numerous studies highlighting the variable effects of climate change and pollution on marine organisms independently, there are very few studies focusing on the potential interactive effects of these stressors. The deep-sea is under increasing threat from these anthropogenic stressors, especially cold-water coral (CWC) communities which contribute to nutrient and carbon cycling, as well as providing biogenic habitats, feeding grounds, and nurseries for many fishes and invertebrates. The primary goals of this dissertation are to assess the vulnerability of CWCs to independent and interacting anthropogenic stressors in their environment; including natural hydrocarbon seepage, hydrocarbon and dispersant concentrations released during an accidental oil spill (i.e. Deepwater Horizon), and the interacting effects of climate change-related factors and hydrocarbon/dispersant exposure. To address these goals, multiple stressor experiments were implemented to assess the effects of current and future conditions [(a) temp: 8C and pH: 7.9; (b) temp: 8C and pH: 7.6; (c) temp: 12C and pH: 7.9; (d) temp: 12C and pH: 7.6] and oil spill exposure (oil, dispersant, oil + dispersant combined) on coral health using the CWC Lophelia pertusa. Phenotypic response was assessed through observations of diagnostic characteristics that were combined into an average health rating at four points during exposure and recovery. Regardless of environmental condition, average health significantly declined during 24-hour exposure to dispersant alone and increased temperature resulted in a delay in recovery (72 hours) from dispersant exposure. The overall gene expression patterns varied by coral colony, but the dispersant exposure elicited the strongest response. Gene ontology (GO) enrichment analysis revealed that L. pertusa likely experienced varying stages of the cellular stress response (CSR) during exposure to oil, dispersant, and a decrease in pH. The most severe responses were associated with the dispersant exposure including GO terms related to apoptosis, the immune system, wound healing, and stress-related responses. However, the oil exposure induced an upregulation of metabolic pathways and energy transfer but a downregulation of cell growth and development, indicating that the coral nubbins could have been reallocating resources and reducing growth to maintain cellular homeostasis. The decrease in seawater pH elicited a similar response to oil through the enrichment of terms associated with a reduction in the cell cycle and development. Interestingly, the increase in temperature did not elicit a CSR that was detectable in the gene expression data. To further investigate the influence of hydrocarbon exposure on CWCs, comparisons of gene expression profiles were conducted using Callogorgia delta colonies that live in close proximity to active hydrocarbon seepage ("seep") areas with no current active seepage ("non-seep") at two different sites in the Gulf of Mexico. There were fewer differentially expressed genes in the "seep" versus "non-seep" comparison (n=21) than the site comparison (n=118) but both analyses revealed GO terms indicating slight alterations in natural biological housekeeping processes, as opposed to a CSR. Our results indicate that distinct stages of the CSR are induced depending on the intensity of stress. This bolsters the idea that there is a stress response shared by all corals in response to a variety of stressors. These data provide evidence that CWCs can be more negatively impacted, both on the phenotypic and molecular levels, by exposure to chemical dispersants than to hydrocarbons alone. Gaining an understanding of how these communities respond, not only to independent stressors, but the combination of these stressors, provides vital information about how CWC communities will fair in current and future conditions.
