Download or read book Shallow water Benthic Foraminifera as Proxy for Natural Versus Human induced Environmental Change written by and published by . This book was released on 2007 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Benthic Foraminifera and Environmental Change written by Irina Polovodova Asteman and published by Sudwestdeutscher Verlag Fur Hochschulschriften AG. This book was released on 2012-03 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Baltic Sea ecosystem undergoes a high environmental variability due to the occasional ventilation of deep water by highly saline Kattegat water, which enters the Baltic through the narrow and shallow Danish Straits. During the past two decades, the frequency of major inflows decreased and led to extended periods of stagnation with reduced deep-water oxygenation. At the same time, a growing economy caused a significant anthropogenic pollution in the area. The anthropogenic influx of different pollutants caused eutrophication, oxygen depletion and left elevated levels of trace metals in the sediments. These environmental changes are seen today at all trophic levels of living organisms and affected even one of the smallest inhabitants of the Baltic Sea: benthic foraminifera. In this thesis, foraminifera are evaluated as proxies of recent environmental change of both natural and anthropogenic origin in two shallow fjords of the Kiel Bight (SW Baltic Sea).
Download or read book Coastal Signals of Environmental Changes Foraminifera as Benthic Monitors written by Inda Brinkmann and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate changes, tightly linked to anthropogenic activities, are significantly altering environments and ecosystems globally, such as by increasing marine and coastal deoxygenation or occurrences of extreme weather events. The significance of paleoenvironmental and -climate reconstructions, as well as monitoring of current conditions, for unravelling baseline natural variation, today's changes and potential future impacts, has been recognised by the Intergovernmental Panel on Climate Change (IPCC) reports. However, to access past records of physical and chemical environmental variables, and comprehensively assess ecosystem reactions, reliable and sensitive proxies are critical. This thesis' focus lies on benthic foraminifera--unicellular protists with mineralised or organic test, abundantly inhabiting ocean and coastal sediments--and their calibration as indicator for a variety of environmental conditions in field-sampling approaches. The research projects follow two general strategic tracks: (I) a biogeochemical assessment of trace-elemental ratios in foraminiferal calcium-carbonate tests using high-resolution, micro-analytical techniques; (II) a molecular approach investigating foraminiferal environmental DNA derived from coastal sediments. Papers I and II concern the calibration of the benthic foraminiferal Mn/Ca proxy for marine oxygenation conditions in modern field studies. Trace-element concentrations and distributions were measured by plasma-, laser- and synchrotron-based analyses in a high-resolution, individual-foraminifera approach, and interpreted in the context of ambient physical and chemical conditions of the water column, pore-waters and sediments (including oxygen and manganese concentrations). Investigating two coastal systems with almost permanently severely oxygen-deficient bottom-waters (Santa Barbara Basin, Paper I), and undergoing a seasonal oxygenation cycle across the low- to well-oxygenated range (Gullmar Fjord, Paper II), respectively, demonstrated the utility of the Mn/Ca proxy for indicating low-oxygen conditions specifically. Continued calibration efforts under consideration of ambient oxygenation and redox regimes may open further possibilities of quantitative oxygen reconstructions. Paper III explores the use of coastal, benthic Ba/Ca records as indicator of riverine runoff and drought on land across the years 2018 and 2019, characterised by severe heat and drought, and warm and wet conditions, respectively. Benthic Ba/Ca correlated significantly with the hydroclimate conditions, as inferred from extensive meteorological and hydrological data sets of the region, highlighting qualitative proxy potential for paleo-drought reconstructions. Based on ambient sediment and pore-water geochemistry, we discuss mediation of water-column transport and pore-water Ba cycling by Fe and Mn oxides. All three investigations of these geochemical proxies (Paper I-III) highlighted the significance of biological controls on foraminiferal TE/Ca, which are species-specific and, thus, should be a deciding factor in choosing proxy candidate species. In particular the influences of micro-habitat distribution and utilised metabolic pathways by foraminifera are discussed in detail. In Paper IV foraminiferal biodiversity and assemblage responses to natural and anthropogenic environmental trends in a fjord system (Swedish west coast) are documented in a metabarcoding approach. Environmental DNA successfully tracked biodiversity and community composition changes associated with contrasting ecosystems but showed damped sensitivity to environmental variability on sub-annual time-scales. Overlaps and discrepancies between molecular and traditional, observation-based assessment techniques, as well as future trajectories to resolve uncertainties are discussed. Overall, this thesis solidifies and expands the currently available proxy toolbox for reconstructions of both coastal low-oxygen, as well as terrestrial hydroclimate conditions. The findings contribute towards filling current knowledge gaps pertaining to biotic impacts on foraminifera-derived biogeochemical signals and methodological uncertainties in metabarcoding approaches and highlight the significance of implementing molecular techniques in conventional foraminiferal assemblage studies.
Download or read book Modern Foraminifera written by Barun K. Sen Gupta and published by Springer Science & Business Media. This book was released on 2007-05-08 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the reviews: "This is now the definitive, authoritative text on applied foraminiferal micropaleontology and should be in the library of all practicing micropaleontologists." (William A. Berggren, Woods Hole Oceanographic Institution in Micropaleontology, 47:1 (2001)"During the last 20 years there has been an explosion of publications about foraminifera from an amazing variety of disciplines: basic cell biology, algal symbiosis, biomineralization, biogeography, ecology, pollution, chemical oceanography, geochemistry, paleoceanography, and geology. This book summarizes contributions by leading researchers in these diverse fields. It is not just another text on the biology of foraminifera. Rather, Barun Sen Gupta has accomplished his objective to "write an advanced text for university students that would also serve as a reference book for professionals"." (Howard J. Spero, University of California at Davis in Limnology and Oceanography, 45:8 (2000).
Download or read book Ecology and Palaeoecology of Benthic Foraminifera written by John W. Murray and published by Routledge. This book was released on 2014-10-13 with total page 878 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an important and authoritative review of foraminiferal ecology, the first for over a decade. Professor Murray relates ecological data on living forms of foraminifera to the palaeoecology of fossil species, and defines in detail areas of global distribution.
Download or read book Spatio temporal Distribution of Benthic Foraminifera in Intertidal Areas of Hauts de france written by Fabio Francescangeli and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Foraminifera are unicellular eukaryotes widespread in all marine environments. Modern benthic foraminifera own specific characteristics (i.e., high abundance, high diversity, easy to collect, well preserved) that make them good tools to highlight global and local environmental changes. Over the recent past the estuarine areas of the Hauts-de-France region, experienced differential degree of human disturbance. The principal objectives of this work are within this area, 1) to describe the benthic foraminiferal distributions and 2) to investigate their response to short- (annual and seasonal) and long-term (hundred years) environmental changes. This has been performed across both pristine and anthopogenized intertidal areas of the region. Faunal analyses have been coupled with sedimentological and geochemical analyses, to better understand the control of environmental parameters on driving spatial and temporal variations of benthic foraminifera. Different intertidal living foraminiferal assemblages are distinguished reflecting the main environmental drivers identified in the Hauts-de-France region. Long-term scale observations have allowed distinguishing both natural and human-induced environmental transformations through monitoring benthic foraminiferal changings. The study demonstrates the potential of foraminifera as bioindicators for application in environmental monitoring.
Download or read book Recent New Zealand Shallow water Benthic Foraminifera written by Bruce William Hayward and published by . This book was released on 1999 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Benthic Foraminifera Assemblages from Shallow water Ecosystems written by Olugbenga Temitope Fajemila and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ocean Acidification written by National Research Council and published by National Academies Press. This book was released on 2010-09-14 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ocean has absorbed a significant portion of all human-made carbon dioxide emissions. This benefits human society by moderating the rate of climate change, but also causes unprecedented changes to ocean chemistry. Carbon dioxide taken up by the ocean decreases the pH of the water and leads to a suite of chemical changes collectively known as ocean acidification. The long term consequences of ocean acidification are not known, but are expected to result in changes to many ecosystems and the services they provide to society. Ocean Acidification: A National Strategy to Meet the Challenges of a Changing Ocean reviews the current state of knowledge, explores gaps in understanding, and identifies several key findings. Like climate change, ocean acidification is a growing global problem that will intensify with continued CO2 emissions and has the potential to change marine ecosystems and affect benefits to society. The federal government has taken positive initial steps by developing a national ocean acidification program, but more information is needed to fully understand and address the threat that ocean acidification may pose to marine ecosystems and the services they provide. In addition, a global observation network of chemical and biological sensors is needed to monitor changes in ocean conditions attributable to acidification.
Download or read book Natural Climate Variability on Decade to Century Time Scales written by National Research Council and published by National Academies Press. This book was released on 1996-08-30 with total page 645 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reflects the current state of scientific knowledge about natural climate variability on decade-to-century time scales. It covers a wide range of relevant subjects, including the characteristics of the atmosphere and ocean environments as well as the methods used to describe and analyze them, such as proxy data and numerical models. They clearly demonstrate the range, persistence, and magnitude of climate variability as represented by many different indicators. Not only do natural climate variations have important socioeconomic effects, but they must be better understood before possible anthropogenic effects (from greenhouse gas emissions, for instance) can be evaluated. A topical essay introduces each of the disciplines represented, providing the nonscientist with a perspective on the field and linking the papers to the larger issues in climate research. In its conclusions section, the book evaluates progress in the different areas and makes recommendations for the direction and conduct of future climate research. This book, while consisting of technical papers, is also accessible to the interested layperson.
Download or read book The Anthropocene as a Geological Time Unit written by Jan Zalasiewicz and published by Cambridge University Press. This book was released on 2019-03-07 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reviews the evidence underpinning the Anthropocene as a geological epoch written by the Anthropocene Working Group investigating it. The book discusses ongoing changes to the Earth system within the context of deep geological time, allowing a comparison between the global transition taking place today with major transitions in Earth history.
Download or read book Environmental Micropaleontology written by Ronald E. Martin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microfossils are ideally suited to environmental studies because their short generation times allow them to respond rapidly to environmental change. This book represents an assessment of the progress made in environmental micropalaeontology and sets out future research directions. The taxa studied are mainly foraminifera, but include arcellaceans, diatoms, dinoflagellates, and ostracodes. The papers themselves range from reviews of applications of particular taxa to specific case studies.
Download or read book Understanding Earth s Deep Past written by National Research Council and published by National Academies Press. This book was released on 2011-08-02 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is little dispute within the scientific community that humans are changing Earth's climate on a decadal to century time-scale. By the end of this century, without a reduction in emissions, atmospheric CO2 is projected to increase to levels that Earth has not experienced for more than 30 million years. As greenhouse gas emissions propel Earth toward a warmer climate state, an improved understanding of climate dynamics in warm environments is needed to inform public policy decisions. In Understanding Earth's Deep Past, the National Research Council reports that rocks and sediments that are millions of years old hold clues to how the Earth's future climate would respond in an environment with high levels of atmospheric greenhouse gases. Understanding Earth's Deep Past provides an assessment of both the demonstrated and underdeveloped potential of the deep-time geologic record to inform us about the dynamics of the global climate system. The report describes past climate changes, and discusses potential impacts of high levels of atmospheric greenhouse gases on regional climates, water resources, marine and terrestrial ecosystems, and the cycling of life-sustaining elements. While revealing gaps in scientific knowledge of past climate states, the report highlights a range of high priority research issues with potential for major advances in the scientific understanding of climate processes. This proposed integrated, deep-time climate research program would study how climate responded over Earth's different climate states, examine how climate responds to increased atmospheric carbon dioxide and other greenhouse gases, and clarify the processes that lead to anomalously warm polar and tropical regions and the impact on marine and terrestrial life. In addition to outlining a research agenda, Understanding Earth's Deep Past proposes an implementation strategy that will be an invaluable resource to decision-makers in the field, as well as the research community, advocacy organizations, government agencies, and college professors and students.
Download or read book Benthic Foraminifera of the Gulf of Mexico written by C. Wylie Poag and published by Texas A&M University Press. This book was released on 2015-03-15 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1981, Woods Hole researcher C. Wylie Poag published the book Ecological Atlas of the Benthic Foraminifera of the Gulf of Mexico. In this new volume, Poag has revised and updated the atlas, incorporating three decades of extensive data collections from the open Gulf and from an additional seventeen estuarine systems to cover species of benthic foraminifera from more than eight thousand sample stations. Benthic Foraminifera of the Gulf of Mexico features 68 plates of scanning electron photomicrographs, 64 color figures, and a large color foldout map, indicating species distribution of forams. This book is designed to aid students and teachers of geology, biology, oceanography, and ecology, as well as micropaleontologists in government and industry laboratories, and other researchers and consultants who have an interest in benthic ecology or paleoecology.
Download or read book Benthic Foraminifera Environmental Change in the South western Baltic Sea written by Irina Polovodova and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Encyclopedia of Paleoclimatology and Ancient Environments written by Vivien Gornitz and published by Springer Science & Business Media. This book was released on 2008-10-31 with total page 1062 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of Springer’s Major Reference Works, this book gives the reader a truly global perspective. It is the first major reference work in its field. Paleoclimate topics covered in the encyclopedia give the reader the capability to place the observations of recent global warming in the context of longer-term natural climate fluctuations. Significant elements of the encyclopedia include recent developments in paleoclimate modeling, paleo-ocean circulation, as well as the influence of geological processes and biological feedbacks on global climate change. The encyclopedia gives the reader an entry point into the literature on these and many other groundbreaking topics.
Download or read book Ecology and Applications of Benthic Foraminifera written by John W. Murray and published by Cambridge University Press. This book was released on 2006-10-26 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher description
