Degradation of Dissolved Organic Carbon in Permeable Coastal Sediments PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Degradation of Dissolved Organic Carbon in Permeable Coastal Sediments PDF full book. Access full book title Degradation of Dissolved Organic Carbon in Permeable Coastal Sediments by Lindsay Chipman. Download full books in PDF and EPUB format.
Author: Lindsay Chipman Publisher: ISBN: Category : Languages : en Pages :
Book Description
Approximately 70% of the shelf sediments are relict sands (Riggs et al., 1996), and in the shallow coastal zone a large fraction of these sands are highly permeable and permit circulation of water through the interstitial space (Marinelli et al., 1998; Huettel et al., 1996; Huettel and Gust, 1992). In this shallow environment, strong boundary currents caused by wind, waves, and tides force bottom water loaded with DOC through the sediment ripples and upper surface layers of the sand. Abundance and diversity of microbes in permeable sediments exceed that of the overlying water column (Hunter et al., 2006), and the question arises whether the filtration through the sediment affects the decomposition of DOC and water column DOC dynamics. I tested the working hypotheses that rapid DOC transport along relatively short pathways through the sand significantly enhances the degradation of the DOC and that the sedimentary flushing tightly links sedimentary and water column DOC concentrations.
Author: Lindsay Chipman Publisher: ISBN: Category : Languages : en Pages :
Book Description
Approximately 70% of the shelf sediments are relict sands (Riggs et al., 1996), and in the shallow coastal zone a large fraction of these sands are highly permeable and permit circulation of water through the interstitial space (Marinelli et al., 1998; Huettel et al., 1996; Huettel and Gust, 1992). In this shallow environment, strong boundary currents caused by wind, waves, and tides force bottom water loaded with DOC through the sediment ripples and upper surface layers of the sand. Abundance and diversity of microbes in permeable sediments exceed that of the overlying water column (Hunter et al., 2006), and the question arises whether the filtration through the sediment affects the decomposition of DOC and water column DOC dynamics. I tested the working hypotheses that rapid DOC transport along relatively short pathways through the sand significantly enhances the degradation of the DOC and that the sedimentary flushing tightly links sedimentary and water column DOC concentrations.
Author: Lindsay Chipman Publisher: ISBN: Category : Marine biology Languages : en Pages :
Book Description
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.
Author: Jack J. Middelburg Publisher: Springer ISBN: 3030108228 Category : Science Languages : en Pages : 118
Book Description
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.
Author: Dennis A. Hansell Publisher: Elsevier ISBN: 0443138591 Category : Science Languages : en Pages : 870
Book Description
Biogeochemistry of Marine Dissolved Organic Matter, 3rd edition is the most up-to-date revision of the fundamental reference for the biogeochemistry of marine dissolved organic matter. Since its original publication in June 2002, the science, questions, and priorities have advanced, and the editors of this essential guide, have added nine new chapters, including one on the South China Sea. An indispensable manual edited by the most distinguished experts in the field, this book is addressed to graduate students, marine scientists, and all professionals interested in advancing their knowledge of the field. Features up-to-date knowledge on DOM, including 9 new chapters Presents the only published work to synthesize recent research on dissolved organic carbon in the South China, a region receiving a great deal of attention in recent decades Offers contributions by world-class research leaders
Author: Dennis A. Hansell Publisher: Academic Press ISBN: 0124071538 Category : Science Languages : en Pages : 712
Book Description
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
Author: Deborah J. Read Publisher: ISBN: Category : Aquatic ecology Languages : en Pages : 156
Book Description
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.
Author: Glenn Lopez Publisher: Springer Science & Business Media ISBN: 1468476718 Category : Science Languages : en Pages : 333
Book Description
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.
Author: M. Schwartz Publisher: Springer Science & Business Media ISBN: 1402038801 Category : Science Languages : en Pages : 1243
Book Description
This new Encyclopedia of Coastal Science stands as the latest authoritative source in the field of coastal studies, making it the standard reference work for specialists and the interested lay person. Unique in its interdisciplinary approach. This Encyclopedia features contributions by 245 well-known international specialists in their respective fields and is abundantly illustrated with line-drawings and photographs. Not only does this volume offer an extensive number of entries, it also includes various appendices, an illustrated glossary of coastal morphology and extensive bibliographic listings.
Author: Lindsay Chipman
Author: Lindsay Chipman
Author: Lindsay Chipman
Author: Jack J. Middelburg
Author: Dennis A. Hansell
Author: Dennis A. Hansell
Author: Kelly Lynne Taylor
Author: Deborah J. Read
Author: SungHyun Nam
Author: Glenn Lopez
Author: M. Schwartz