Response Of Benthic Foraminifera To Environmental Variability
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Response Of Benthic Foraminifera To Environmental Variability
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Author : Maria Virginia Alves Martins
language : en
Publisher:
Release Date : 2019
Response Of Benthic Foraminifera To Environmental Variability written by Maria Virginia Alves Martins and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019 with Science categories.
Foraminifera are eukaryotic unicellular microorganisms inhabiting all marine environments. The study of these protists has huge potential implications and benefits. They are good indicators of global change and are also promising indicators of the environmental health of marine ecosystems. Nevertheless, much remains to be learned about foraminiferal ecology. The goals of this chapter are (1) to provide a few examples from foraminifera studies, presenting possible use of foraminifera as bioindicators for the monitoring of transitional and marine ecosystems and (2) to highlight the importance of applying these organisms in environmental monitoring studies. A semienclosed coastal lagoon (Aveiro Lagoon; Portugal), an estuarine system (S√£o Sebasti√£o Channel; SE Brazil), a continental shelf sector (Campos Basin; SE Brazil), and a segment of continental slope (Campos Basin; SE Brazil) are used as examples.
Foraminiferal Response To Environmental Variability Along The California Margin
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Author : Catherine Van Wie Davis
language : en
Publisher:
Release Date : 2016
Foraminiferal Response To Environmental Variability Along The California Margin written by Catherine Van Wie Davis and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
Foraminifera, marine protists, are ubiquitous throughout the worlds oceans, contributing to pelagic and benthic ecosystems, global carbon cycling and in producing an extensive fossil record ideal for paleoclimate reconstruction as well as for exploring macroevolutionary questions. As such, the morphology, species assemblages and geochemistry of fossil foraminifera each contain extensive information about their growth and depositional environment. Here, the responses of foraminifera along the California Margin are examined across a range of naturally occurring hydrographic variables and at differing time scales. Chapter 1 explores the potential for size and weight change in fossil calcareous benthic foraminifera across a temporal change in oxygen and inorganic carbon. Previous work has demonstrated that changes in both oxygen and pH can impact foraminiferal calcification. Four species of benthic foraminifera from a sediment core in Santa Barbara Basin were weighed and measured against a backdrop of well-resolved, decadal scale Oxygen Minimum Zone and corresponding Carbonate Maximum Zone fluctuations at the site over the last 15,000 years. The resulting record shows long-term species-specific fluctuations in size and size-normalized weight. Chapter 2 focuses on the species level planktic foraminiferal response to seasonal upwelling on the Central California shelf. The region off of Bodega Head, California experiences wind-driven coastal upwelling which seasonally brings deeper, colder, nutrient rich, oxygen poor, and CO2 enriched waters to the near surface. A distinct difference is observed in the relative abundances of species found during and outside of upwelling season, with Globigerina bulloides associated with non-upwelled waters, Turborotalia quinqueloba and Neogloboquadrina pachyderma found primarily during upwelling season, and Neogloboquadrina incompa present year-round but more relatively abundant outside of upwelling season. Chapter 3 builds from previous observations of decreased foraminifera calcification in response to low pH or [CO32−] to further probe the physiologic response of foraminifera to these conditions. Foraminifer G. bulloides was subjected in the laboratory to an ecologically relevant range of environmental pH treatments (7.5-8.3) and evaluated on both respirometry and calcification metrics. Results indicated a decrease in calcification with decreasing pH and reduced shell-repair at low pH, but a non-linear respiratory response, with metabolic depression at low pH, and the highest respiration rates observed at pH ~8.1. Chapter 4 presents species-specific Mg/Ca:temperature relationships for the cold-water planktic foraminifera species N. pachyderma and N. incompta. No significant pH effect on Mg/Ca is demonstrated at 12 °C in N. incompta. However, N. incompta did form a low Mg/Ca “crust” in culture at the same temperature as ontogenetic (higher Mg/Ca) calcite. This chapter therefore proposes a Mg/Ca:temperature relationship exclusive to ontogenetic calcite and presents a corroboration of this approach in fossil N. pachyderma and N. incompta. Through these chapters, the foraminiferal response in terms of morphology, species compositions, physiology and geochemistry is documented with respect the the range of conditions relevant to the modern California Margin. The results of each of these approaches inform the paleoceaongraphic interpretation of this and analogous regions, highlighting the importance of approaching paleoceaongraphic interpretations with species and regional specificity to the greatest extent possible. This necessitates relating the morphology and geochemistry of foraminiferal species to the environment in which they are endemic, and taking into account the ecology, physiology and life history or foraminifera populations when interpreting paleoclimate proxies.
Coastal Signals Of Environmental Changes Foraminifera As Benthic Monitors
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Author : Inda Brinkmann
language : en
Publisher:
Release Date : 2022
Coastal Signals Of Environmental Changes Foraminifera As Benthic Monitors written by Inda Brinkmann and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2022 with categories.
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.
Ecology And Palaeoecology Of Benthic Foraminifera
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Author : John W. Murray
language : en
Publisher: Routledge
Release Date : 2014-10-13
Ecology And Palaeoecology Of Benthic Foraminifera written by John W. Murray and has been published by Routledge this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014-10-13 with Science categories.
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.
Ecology And Applications Of Benthic Foraminifera
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Author : John W. Murray
language : en
Publisher: Cambridge University Press
Release Date : 2006-10-26
Ecology And Applications Of Benthic Foraminifera written by John W. Murray and has been published by Cambridge University Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2006-10-26 with Science categories.
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Monitoring Of Marine Pollution
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Author : Houma Bachari Fouzia
language : en
Publisher: BoD – Books on Demand
Release Date : 2019-06-05
Monitoring Of Marine Pollution written by Houma Bachari Fouzia and has been published by BoD – Books on Demand this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019-06-05 with Technology & Engineering categories.
Many of the pollutants discharged into the sea are directly or indirectly the result of human activities. Some of these substances are biodegradable, while others are not. This study is devoted to monitoring areas of the environment. Methods assessment is based on monitoring data and an evaluation of the impact of pollution.Surveillance provides a scientific basis for standards development and application. The methodology of marine pollution control is governed by algorithms and models. A monitoring strategy should be put in place, coupled with an environmental assessment concept, through targeted research activities in areas identified at local and regional levels. This concept will make it possible to diagnose the state of "health" of these zones and consequently to correct any anomalies. Monitoring of the marine and coastal environment is based on recent methods and validated after experiments in the field of marine pollution.
Environmental Micropaleontology
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Author : Ronald E. Martin
language : en
Publisher: Springer Science & Business Media
Release Date : 2012-12-06
Environmental Micropaleontology written by Ronald E. Martin and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012-12-06 with Science categories.
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.
Paleoecology Biostratigraphy Paleoceanography And Taxonomy Of Agglutinated Foraminifera
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Author : Christoph Hemleben
language : en
Publisher: Springer Science & Business Media
Release Date : 2012-12-06
Paleoecology Biostratigraphy Paleoceanography And Taxonomy Of Agglutinated Foraminifera written by Christoph Hemleben and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012-12-06 with Science categories.
Agglutinated foraminifera are among the most widely distributed and abundant groups of marine meiofauna in some environments (e. g. marshes, deep-sea). They are tolerant of environmental extremes, tending to live where the evolutionarily more advanced calcareous foraminifera cannot survive. However, largely because of historical reasons, the amount of scientific effort invested in this group has been small in comparison to studies of other marine organisms. The NATO Advanced Studies Institute conference on the paleoecology, biostratigraphy, paleoceanography and taxonomy of agglutinated foraminifera in TUbingen September 17-29, 1989, was a direct outgrowth of two previous workshops on agglutinated foraminifers held in Amsterdam in September 1981 (IW AF I) and in Vienna in June 1986 (IW AF 11). As such, the TUbingen conference constitutes the Third International Workshop on Agglutinated Foraminifera (IW AF III) and was organised to provide a platform for synthesizing the current state of knowledge on this group of organisms, and to strengthen interactions between basic research and applied micropaleontology. One of the main underlying themes of the conferen:e was to identify topics in the paleoecology, biostratigraphy, paleoceanography and taxonomy of agglutinated foraminifera which are in urgent need of further research. About 80 scientists and students from 5 continents participated in the TUbingen conference, which is one measure of the growth in interest in agglutinated foraminifers over the past decade. During four days of technical sessions, scientific results were communicated in the form of 34 oral presentations and 15 poster displays.
Modern Foraminiferal Assemblages Of The Denmark Strait
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Author : Laura Larocca
language : en
Publisher:
Release Date : 2016
Modern Foraminiferal Assemblages Of The Denmark Strait written by Laura Larocca and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
Foraminifera occupy a geological range from the early Cambrian to the present day. Their well preserved shells, high relative abundance, and short response time to changing environmental conditions make foraminifera ideal proxies for environmental change. Benthic foraminifera are a valuable but poorly understood paleobiological proxy for the reconstruction of environmental conditions on continental shelves occupied by arctic and subarctic waters. This study identifies, examines, and quantifies calcareous benthic foraminiferal faunas from a sediment core taken from the Denmark Strait. Our analysis of three-thousand individuals from ten discrete samples aim to provide a better understanding of the modern patterns of foraminiferal distribution in the Denmark Strait, an important area in regulating climate. We find that the variability in foraminiferal taxa reflect changes in the environment, specifically current velocity, over the past (approximately) 600 years. The dominant genera, Cibicides, Elphidium, and Buccella, in the studied core have shown significant variability in abundance through time. The variability in these genera support a change from a warmer climate with stronger current velocities and meltwater influx (likely the Medieval Warm Period) to a cooler climate, with slower current velocities and less meltwater influx (most likely the Little Ice age), and finally a shift to our present day environment in which the climate in the region is warming due to anthropogenic impacts. Although more work needs to be done, it is clear that benthic foraminifera in the region respond to changing climate conditions and are valuable proxies for environmental change.
Spatio Temporal Distribution Of Benthic Foraminifera In Intertidal Areas Of Hauts De France
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Author : Fabio Francescangeli
language : en
Publisher:
Release Date : 2017
Spatio Temporal Distribution Of Benthic Foraminifera In Intertidal Areas Of Hauts De France written by Fabio Francescangeli and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017 with categories.
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.