Author: Irina PolovodovaPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Benthic Foraminifera & Environmental Change in the South-western Baltic Sea
Benthic Foraminifera & Environmental Change in the South-western Baltic Sea
Author: Irina PolovodovaBenthic Foraminifera and Environmental Change
Author: Irina Polovodova AstemanPublisher: Sudwestdeutscher Verlag Fur Hochschulschriften AG
ISBN: 9783838131757
Category :
Languages : en
Pages : 128
Book Description
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).
Benthic Foraminifera and Enviromental Change in the South-Western Baltic-Sea
Author: Irina PolovodovaImpact of Elevated PCO2 on Benthic Foraminifera from the Southwestern Baltic Sea
Author: Kristin HaynertUse of Proxies in Paleoceanography
Author: Gerhard FischerPublisher: Springer Science & Business Media
ISBN: 3642586465
Category : Science
Languages : en
Pages : 768
Book Description
Paleoceanographic proxies provide infonnation for reconstructions of the past, including climate changes, global and regional oceanography, and the cycles of biochemical components in the ocean. These prox ies are measurable descriptors for desired but unobservable environmental variables such as tempera ture, salinity, primary productivity, nutrient content, or surface-water carbon dioxide concentrations. The proxies are employed in a manner analogous to oceanographic methods. The water masses are first characterized according to their specific physical and chemical properties, and then related to particular assemblages of certain organisms or to particular element or isotope distributions. We have a long-standing series of proven proxies available. Marine microfossil assemblages, for instance, are employed to reconstruct surface-water temperatures. The calcareous shells of planktonic and benthic microorgan isms contain a wealth of paleoceanographic information in their isotopic and elemental compositions. Stable oxygen isotope measurements are used to detennine ice volume, and MglCa ratios are related to water temperatures, to cite a few examples. Organic material may also provide valuable infonnation, e. g. , about past productivity conditions. Studying the stable carbon isotope composition of bulk organic matter or individual marine organic components may provide a measure of past surface-water CO 2 conditions within the bounds of certain assumptions. Within the scope of paleoceanographic investigations, the existing proxies are continuously evolving and improving, while new proxies are being studied and developed. The methodology is improved by analysis of samples from the water column and surface sediments, and through laboratory experiments.
Ecology and Applications of Benthic Foraminifera
Author: John W. MurrayPublisher: Cambridge University Press
ISBN: 0521828392
Category : Science
Languages : en
Pages : 320
Book Description
Publisher description
Biological Oceanography of the Baltic Sea
Author: Pauline Snoeijs-LeijonmalmPublisher: Springer Science & Business Media
ISBN: 9400706685
Category : Science
Languages : en
Pages : 696
Book Description
This is the first comprehensive science-based textbook on the biology and ecology of the Baltic Sea, one of the world’s largest brackish water bodies. The aim of this book is to provide students and other readers with knowledge about the conditions for life in brackish water, the functioning of the Baltic Sea ecosystem and its environmental problems and management. It highlights biological variation along the unique environmental gradients of the brackish Baltic Sea Area (the Baltic Sea, Belt Sea and Kattegat), especially those in salinity and climate. pt;font-family:"Arial","sans-serif"; color:#262626">The first part of the book presents the challenges for life processes and ecosystem dynamics that result from the Baltic Sea’s highly variable recent geological history and geographical isolation. The second part explains interactions between organisms and their environment, including biogeochemical cycles, patterns of biodiversity, genetic diversity and evolution, biological invasions and physiological adaptations. In the third part, the subsystems of the Baltic Sea ecosystem – the pelagic zone, the sea ice, the deep soft sea beds, the phytobenthic zone, the sandy coasts, and estuaries and coastal lagoons – are treated in detail with respect to the structure and function of communities and habitats and consequences of natural and anthropogenic constraints, such as climate change, discharges of nutrients and hazardous substances. Finally, the fourth part of the book discusses monitoring and ecosystem-based management to deal with contemporary and emerging threats to the ecosystem’s health.
Coastal Signals of Environmental Changes: Foraminifera as Benthic Monitors
Author: Inda BrinkmannPublisher:
ISBN: 9789187847677
Category :
Languages : en
Pages : 0
Book Description
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.
(Table1) Living and Dead Benthic Foraminifera Abundance in Sediments of the Bottsand-Lagoon, Western Baltic Sea, Supplementary Data To: Lutze, Gerhard F (1968): Jahresgang Der Foraminiferen-Fauna in Der Bottsand-Lagune (westliche Ostsee). Meyniana, 18, 13-30
Author: Gerhard Friedrich LutzePublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Seasonal collections were made from 3 stations in a brackish lagoon near Kiel/Germany from December 1964 to June 1967. In addition 120 samples were taken in June 1966 to investigate the general pattern of distribution. Two species of the offshore fauna were found to dominate the lagoon (high population densities): Cribrononion articulatum and Miliammina fusca. The 'Vegetation zone' of the lagoon contains an assemblage of seven euryhaline arenaceous species. All of them were previously recorded from different regions of the world. - C. articulatum seems to prefer shallow water with a high daily range of water temperature (up to 30° Cels.). Population density and distribution show considerable differences between the different years. Size distribution curves of C. articulatum indicate main reproduction activity in spring and subsequent growth in uniform populations. Growth is terminated after six months but most of the specimens will either die in winter or reproduce the next spring; only a smaller amount is reproducing in summer or autumn. - Annual differences of the observed degree make it difficult to calculate foraminiferal productivity in a lagoonal environment and require seasonal observation over a period of at least 3 or 4 years.