Download or read book The Role of Labile Dissolved Organic Carbon in Influencing Fluxes Across the Sediment water Interface written by Deborah J. Read and published by . This book was released on 2008 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sediment diagenesis in aquatic systems is usually understood to be controlled by the concentrations of both organic carbon and the oxidant. However, the concept that sediment respiration may be limited by the supply of organic carbon, even in systems with moderate concentrations of organic carbon in the water column, has yet to be fully explored. Typically we assume that a direct coupling between water column and sediment diagenesis processes occurs and the chemical evolution of porewater and surface water are linked through fluxes of chemical species across the sediment-water interface. While the dynamics of supply of particulate organic carbon (POC) to the sediments via plankton deposition and resuspension, has previously been examined, the fate of dissolved organic carbon (DOC) once in the sediments, has rarely been investigated. A series of experiments comprising batch tests, microcosms and sediment cores were conducted on sediment and water from four diverse field sites in which sediment respiration was considered to be carbon limited. Three sites were oligotrophic, acidic lakes and the fourth an oligotrophic coastal embayment. During each experiment dissolved organic carbon was added and measurements were undertaken of solutes that were considered participants in diagenetic processes. While each system differed in its chemical, biological and geological makeup, a key commonality was the rapid onset of anoxic conditions in the sediments irrespective of the overlying water oxygen concentrations, indicating lack of direct coupling between biogeochemical processes in the water column and sediments. Also, similar apparent DOC remineralisation rates were observed, measured solute fluxes after the addition of DOC indicated adherence to the ecological redox sequence, and increased ammonium concentrations were measured in the overlying waters of the acidic microcosms. In marine system experiments it was noted that diagenetic respiration, as indicated by decreasing concentrations of oxygen in the overlying water, increased rapidly after labile DOC was added. To explore the influence of geochemical processes on sediment respiration, a diagenetic model was tested against the laboratory data. The model was able to capture the rapid changes observed in the microcosms after addition of DOC in both the marine and acidic systems experiments. The model has the potential to serve as an essential tool for quantifying sediment organic matter decomposition and dissolved chemical fluxes. This work has focussed our attention on the control of DOC availability on sediment respiration and thus its ultimate control on solute fluxes across the sediment water interface. The results highlight the need to understand and quantify the supply of DOC to the sediment (as POC or already as the dissolved form), its transport through the sediment and its eventual remineralisation. This understanding is critical for improved management of aquatic systems, possibly even in systems where water column organic carbon is plentiful but sediment respiration is constrained by high organic carbon turnover rates in the water column and a resulting low flux of organic carbon to the sediment.
Download or read book Marine Carbon Biogeochemistry written by Jack J. Middelburg and published by Springer. This book was released on 2019-01-25 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book discusses biogeochemical processes relevant to carbon and aims to provide readers, graduate students and researchers, with insight into the functioning of marine ecosystems. A carbon centric approach has been adopted, but other elements are included where relevant or needed. The book focuses on concepts and quantitative understanding of primary production, organic matter mineralization and sediment biogeochemistry. The impact of biogeochemical processes on inorganic carbon dynamics and organic matter transformation are also discussed.
Download or read book Role of the Sediments for Dissolved Organic Carbon DOC in Drinking Water Reservoirs written by Tallent Dadi and published by . This book was released on 2017* with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Benthic Flux; Dissolved Organic Carbon (DOC); Microbial Metabolic Potential; Resuspension; Sediment Core Incubation; Sediment-Water-Interface
Download or read book The Benthic Boundary Layer written by Bernard P. Boudreau and published by Oxford University Press. This book was released on 2001-03-22 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: The benthic boundary layer is the zone of water and sediment immediately adjacent to the bottom of a sea, lake, or river. This zone is of considerable interest to biologists, geochemists, sedimentologists, and engineers because of very strong gradients of energy, dissolved and solid chemical components, suspended matter, and the number of organisms that live there. It is, for example, the sink for anthropogenic substances and the home of microscopic plant life that provides the nutrients that determine fish populations--and ultimately the size of the fisheries. This book of original chapters edited by Professors Boudreau and Jorgensen, both leading researchers in the field, will meet the need for an up-to-date, definitive text/reference on measurements, techniques, and models for transport and biochemical processes in the benthic boundary layer. Each chapter provides a comprehensive review of a selected field, with illustrated examples from the authors' own work. The book will appeal to professionals and researchers in marine biology, marine chemistry, marine engineering, and sedimentology.
Download or read book Biogeochemistry of Marine Dissolved Organic Matter written by Dennis A. Hansell and published by Academic Press. This book was released on 2014-10-02 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine dissolved organic matter (DOM) is a complex mixture of molecules found throughout the world's oceans. It plays a key role in the export, distribution, and sequestration of carbon in the oceanic water column, posited to be a source of atmospheric climate regulation. Biogeochemistry of Marine Dissolved Organic Matter, Second Edition, focuses on the chemical constituents of DOM and its biogeochemical, biological, and ecological significance in the global ocean, and provides a single, unique source for the references, information, and informed judgments of the community of marine biogeochemists. Presented by some of the world's leading scientists, this revised edition reports on the major advances in this area and includes new chapters covering the role of DOM in ancient ocean carbon cycles, the long term stability of marine DOM, the biophysical dynamics of DOM, fluvial DOM qualities and fate, and the Mediterranean Sea. Biogeochemistry of Marine Dissolved Organic Matter, Second Edition, is an extremely useful resource that helps people interested in the largest pool of active carbon on the planet (DOC) get a firm grounding on the general paradigms and many of the relevant references on this topic. Features up-to-date knowledge of DOM, including five new chapters The only published work to synthesize recent research on dissolved organic carbon in the Mediterranean Sea Includes chapters that address inputs from freshwater terrestrial DOM
Download or read book Oxygen and Dissolved Organic Carbon Dynamics in Permeable Coastal Sediments written by Lindsay Chipman and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: A large fraction of the continental shelf is covered by permeable sediments that are flushed by wave, wind, and tide generated bottom currents. Elevated dissolved organic carbon (DOC) concentrations in coastal zones, a diverse and abundant sediment microbial community, and advective filtration of seawater through the surface layers of permeable sediments, make these environments important zones for the cycling of organic matter. This research investigates the role of permeable sediments in the dynamics of two central components of the carbon cycle: DOC and oxygen. In Chapter 2, published in Limnology & Oceanography, I investigate decomposition rates and compositional changes of DOC when filtered through permeable sediments contained in laboratory column reactors. Substantial amounts of DOC were mineralized in the sediments and could be linked to incorporation by aerobic and anaerobic microbes. In DOC pore-water profiles measured at two study sites with permeable sediment, we observed a concave shape of the profiles in the upper 10 cm of permeable sediment resulting from transport of DOC with advective pore water flows into the sand, and DOC decomposition in the subsurface layers. We found that the flushed sand layer between the water column and deeper anoxic sediment layers acts as an effective DOC filter, with subsurface horizontal pore-water flows promoting decomposition of DOC, suggesting that permeable sediments play a key role in the cycling of organic matter. In Chapter 3, submitted to Continental Shelf Research, I use the findings of Chapter 2 for the interpretation of field time series data of DOC, DIC, and TN concentrations in the water column and coastal sediment pore waters. We use these time series to investigate the spatial and temporal dynamics of dissolved organic matter and how benthic pelagic coupling influences DOC concentrations in the permeable sediments. Our results reveal that DOC in the upper layer (0-12 cm) of the shallow sands is controlled by benthic-pelagic coupling facilitated by advective pore water filtration modulated by the regional wave climate. For the quantification of oxygen fluxes in the permeable coastal sands resulting from the benthic organic matter production and consumption and the current-induced sediment flushing, I deployed the eddy correlation technique. In order to make this technique more suitable for our shallow coastal zone with relatively rough hydrodynamic conditions (as compared to deeper marine environments), we adapted existing eddy correlation instruments for use with more durable and repairable oxygen optodes. This development is described in detail in Chapter 4 that has been submitted for publication in Limnology and Oceanography Methods. Our results show that optodes have a comparable response time to electrodes, produce similar fluxes in field deployments, and are a viable alternative for use with the eddy correlation measurement in coastal environments with strong currents and wave action. These hydrodynamic conditions are an important factor controlling production and decomposition processes at the sediment-water interface and within the sediment because they can largely control the availability of DOC and oxygen to microbial communities in the sediments. In Chapter 5, which is presently is being prepared for submission to Marine Ecology - Progress Series, we investigate the relationship between flow, wave height, DOC concentration, temperature, light, and the benthic oxygen fluxes. The results reveal a large range of production and consumption rates in the permeable coastal sediments with distinct seasonal changes. The latter are caused by the availability of degradable organic matter and the magnitude of the pore water flushing process that carries these organic substrates and oxygen into the permeable coastal sands. We conclude that the highly degradable DOC produced by pelagic and benthic primary producers enhances water column - sediment biogeochemical coupling in the coastal zone thereby increasing the contribution of the sediment surface layer in the cycling of carbon and nutrients.
Download or read book An Investigation of Carbon Flux in the Sediment of Castle Lake California written by Frank Stanley Sanders and published by . This book was released on 1976 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sediment Oxygen Demand and Its Effects on Dissolved Oxygen Concentrations and Nutrient Release written by Cynthia B. Price and published by . This book was released on 1994 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluxes between Trophic Levels and through the Water Sediment Interface written by M.-C. Bonin and published by Springer Science & Business Media. This book was released on 1990-12-31 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the Joint Congress of Limnology and Oceanography held in Marseilles, June 26-29, 1989
Download or read book Ecology of Marine Deposit Feeders written by Glenn Lopez and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deposit feeders, animals that derive nutrition from organic matter in sedimentary deposits, are dominant among the inhabitants of muds and, therefore, of the benthos of much of the ocean. In this volume the critical research problems pertaining to deposit feeders are identified and promising approaches for dealing with those problems are proposed. Interdisciplinary approaches are of utmost importance in the study of deposit feeders and their sedimentary environment, merging fields as disparate as nutritional physiology and sediment geochemistry. Among the topics presented are advances in theories of foraging and digestion, and new experimental approaches to study the potential foods, feeding behavior and physiology of animals that ingest sediment.
Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1990 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Deep Carbon written by Beth N. Orcutt and published by Cambridge University Press. This book was released on 2019-10-17 with total page 687 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive guide to carbon inside Earth - its quantities, movements, forms, origins, changes over time and impact on planetary processes. This title is also available as Open Access on Cambridge Core.
Download or read book The Role of Dissolved Organic Carbon in the Terrestrial Carbon Cycle written by Jonathan Sanderman and published by . This book was released on 2007 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissolved Organic Carbon Flux Across the Littoral Zone Sediments of a Midwestern Mesotrophic Lake written by Sandra Jean Hellman and published by . This book was released on 1997 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissolved and Particulate Organic Carbon in Some Colorado Waters written by Edward B. Reed and published by . This book was released on 1971 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Instantaneous amounts of organic carbon, both particulate and dissolved, in a number of freshwaters ranging from unproductive tarns to moderately productive reservoirs were measured by acid-persulfate digestion and infrared absorption. Organic carbon was designated as net seston carbon, filter seston carbon, or dissolved carbon based on filtering techniques. Repeated sampling showed amounts of organic carbon, either dissolved or particulate, fluctuated considerably over short periods of time; the dissolved fraction probably varying less than particulate forms. Almost daily measurements in samples incubated over three week periods also revealed erratic changes, with no clear reduction in total organic carbon. The data have descriptive value, although they cannot, at this time, be related satisfactorily to the general limnological knowledge.
Download or read book Wetland Carbon and Environmental Management written by Ken W. Krauss and published by John Wiley & Sons. This book was released on 2021-11-23 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explores how the management of wetlands can influence carbon storage and fluxes. Wetlands are vital natural assets, including their ability to take-up atmospheric carbon and restrict subsequent carbon loss to facilitate long-term storage. They can be deliberately managed to provide a natural solution to mitigate climate change, as well as to help offset direct losses of wetlands from various land-use changes and natural drivers. Wetland Carbon and Environmental Management presents a collection of wetland research studies from around the world to demonstrate how environmental management can improve carbon sequestration while enhancing wetland health and function. Volume highlights include: Overview of carbon storage in the landscape Introduction to wetland management practices Comparisons of natural, managed, and converted wetlands Impact of wetland management on carbon storage or loss Techniques for scientific assessment of wetland carbon processes Case studies covering tropical, coastal, inland, and northern wetlands Primer for carbon offset trading programs and how wetlands might contribute The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity.Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.
Download or read book Fluxes of Dissolved Organic Carbon from Southampton Water Sediments written by Matthew Thompson and published by . This book was released on 2000 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt:
