Download or read book Nitrogen in the Marine Environment written by Edward J. Carpenter and published by Elsevier. This book was released on 2013-10-22 with total page 919 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen in the Marine Environment provides information pertinent to the many aspects of the nitrogen cycle. This book presents the advances in ocean productivity research, with emphasis on the role of microbes in nitrogen transformations with excursions to higher trophic levels. Organized into 24 chapters, this book begins with an overview of the abundance and distribution of the various forms of nitrogen in a number of estuaries. This text then provides a comparison of the nitrogen cycling of various ecosystems within the marine environment. Other chapters consider chemical distributions and methodology as an aid to those entering the field. This book discusses as well the enzymology of the initial steps of inorganic nitrogen assimilation. The final chapter deals with the philosophy and application of modeling as an investigative method in basic research on nitrogen dynamics in coastal and open-ocean marine environments. This book is a valuable resource for plant biochemists, microbiologists, aquatic ecologists, and bacteriologists.
Download or read book An Examination of the Marine Nitrogen Cycle written by Fabian C. Batista and published by . This book was released on 2016 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: Paleoceanographic studies typically employ stable nitrogen isotopic measurements of total combustible N (delta15NTN) from marine sediments to infer temporal changes in surface ocean marine N dynamics. However, delta 15NTN is a highly non-specific measurement, susceptible to confounding issues including non-marine N sources, and offers little, if any, information regarding degradation and/or alteration of primary delta 15N signals. Recent development of novel biomarker and microfossil based proxies provide new analytical capabilities to circumvent issues with delta 15NTN.
Download or read book Marine Nitrogen Fixation written by Jonathan P. Zehr and published by Springer Nature. This book was released on 2021-04-02 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book aims to serve as a centralized reference document for students and researchers interested in aspects of marine nitrogen fixation. Although nitrogen is a critical element in both terrestrial and aquatic productivity, and nitrogen fixation is a key process that balances losses due to denitrification in both environments, most resources on the subject focuses on the biochemistry and microbiology of such processes and the organisms involved in the terrestrial environment on symbiosis in terrestrial systems, or on largely ecological aspects in the marine environment. This book is intended to provide an overview of N2 fixation research for marine researchers, while providing a reference on marine research for researchers in other fields, including terrestrial N2 fixation. This book bridges this knowledge gap for both specialists and non-experts, and provides an in-depth overview of the important aspects of nitrogen fixation as it relates to the marine environment. This resource will be useful for researchers in the specialized field, but also useful for scientists in other disciplines who are interested in the topic. It would provide a possible text for upper division classes or graduate seminars.
Download or read book Nitrogen Cycling in Coastal Marine Environments written by T. Henry Blackburn and published by . This book was released on 1988-03-21 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen discharge to the coastal environment has been increasing, posing the threat of accelerated eutrofication. Considerable research has been conducted in recent years to examine the impact of the nitrogen loading in coastal ecosystems. Based on proceedings from a SCOPE symposium held at the University of Aarhus in July of 1985, this volume covers a variety of up-to-date developments in research on nitrogen cycling in coastal marine environments. Topics include the role of nitrogen in algal productivity, regeneration of nutrients in the water column and the sediments, and the flow of nitrogen in coastal ecosystems.
Download or read book Nitrogen Cycling in the North Atlantic Ocean and its Watersheds written by Robert W. Howarth and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Human activity has dramatically altered the global nitrogen cycle in recent decades. These changes are not evenly distributed around the world; rather, they are greatest in regions of significant industrial and agricultural activity, as the synthesis and use of inorganic fertilizers, cultivation of legumes, burning of fossil fuels, and the simple act of concentrating humans and animals in dense populations all lead to the release of excess, reactive forms of nitrogen into the environment. In part because reactive nitrogen is frequently a limiting nutrient in many terrestrial and aquatic systems, an excess can lead to a variety of adverse effects on both environmental and human health. The North Atlantic Ocean and its contributing watersheds constitute a region which has seen perhaps the greatest increase in anthropogenically-derived nitrogen. In May of 1994, the International Scope Nitrogen Project, with funding from the Andrew Mellon Foundation, the United Nations Environment Program, and the World Meteorological Organization, sponsored a workshop held on Block Island, RI, USA, entitled `Nitrogen Dynamics of the North Atlantic Basin'. More than 50 scientists from 12 different countries convened with a unique set of goals: an integrated and comprehensive estimate of the current nitrogen cycle of the ocean, coastal systems, and contributing watersheds of the North Atlantic region; an analysis of human-induced changes to those cycles; and an assessment of the current and future effects of human-induced changes to nitrogen cycling throughout the globe.
Download or read book Diatom bound 15N as a Tool to Study the Marine Nitrogen Cycle written by Laura Viviana Morales and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Marine Pelagic Cyanobacteria Trichodesmium and other Diazotrophs written by E.J. Carpenter and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: Planktonic marine cyanobacteria are abundant and significant in the biogeochemistry of the sea. This volume focuses on the filamentous cyanobacteria, particularly those in the genus Trichodesmium which are common in tropical and subtropical seas. A portion of this book also concerns bloom-forming cyanobacteria in the Baltic Sea area. Filamentous cyanobacteria are important as primary producers and for the fixation of atmospheric nitrogen and thus are significant in global cycling of both of these elements. In recent years, through the application of new techniques and intensive multi-disciplinary research programs, progress has been made in understanding both the biology of these cyanobacteria and their place in the marine food web. A broad range of topics is covered in this book, ranging from molecular biology, physiology, ultrastructure, enzyme localization, toxicology, remote sensing, buoyancy, herbivory and the ecology of these organisms in the marine food web. This volume is an outgrowth of a NATO-sponsored meeting held in May 1991 in Bamberg, Germany, and represents the latest synthesis on these marine phytoplankters.
Download or read book The Nitrogen Cycle at Regional to Global Scales written by Elizabeth W. Boyer and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: This issue is the final report from the International SCOPE Project on Nitrogen Transport and Transformations: A Regional and Global Analysis. SCOPE (the Scientific Committee on Problems of the Environment, ICSU) authorized the Nitrogen Project as an 8-year effort between 1994 and 2002 because of the need to better understand how humans have altered nitrogen cyc1ing globally and at the scale of large regions. Human activity has more than doubled the rate of formation of reactive nitrogen on the land surface of the earth, and the nitrogen cyc1e continues to accelerate. The distribution of this reactive nitrogen is not uniform, though, and some regions such as Europe and Asia have seen massive increases in reactive nitrogen, while other regions have seen little change. The SCOPE Nitrogen Project has synthesized detailed information on the nature of the human alteration of the nitrogen cyc1e through aseries of workshops over the past 8 years. These cumulatively have involved over 250 of previous workshops scientists from over 20 different nations. The results have been published in aseries of special journal issues and reports that synthesize information on nitrogen in the North Atlantic Ocean and its water sheds (Howarth 1996), nitrogen cycling in Asia (Hong-Chi Lin et al. 1996; Mosier et al.
Download or read book Nitrogen in the Sea written by Etaro Wada and published by CRC Press. This book was released on 1990-12-07 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides essential information regarding the dynamics and rate processes of nitrogenous compounds in the sea. Topics discussed include characteristics and behavior of nitrogen at the atomic, molecular, and isotopic levels; elemental rate processes and physico-chemical and biological factors; the dynamics of nitrogen in several representative marine ecosystems; and current progress in isotope marine biogeochemistry. The book emphasizes the distribution and variation of nitrogen isotopes, which can provide a novel approach to understanding nitrogen metabolisms occurring in marine ecosystems. Nitrogen in the Sea: Forms, Abundances, and Rate Processes should be considered an indispensable reference tool for researchers and post-graduate students interested in the nitrogen cycle in aquatic ecosystems
Download or read book The Ocean Carbon Cycle and Climate written by Mick Follows and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our desire to understand the global carbon cycle and its link to the climate system represents a huge challenge. These overarching questions have driven a great deal of scientific endeavour in recent years: What are the basic oceanic mechanisms which control the oceanic carbon reservoirs and the partitioning of carbon between ocean and atmosphere? How do these mechanisms depend on the state of the climate system and how does the carbon cycle feed back on climate? What is the current rate at which fossil fuel carbon dioxide is absorbed by the oceans and how might this change in the future? To begin to answer these questions we must first understand the distribution of carbon in the ocean, its partitioning between different ocean reservoirs (the "solubility" and "biological" pumps of carbon), the mechanisms controlling these reservoirs, and the relationship of the significant physical and biological processes to the physical environment. The recent surveys from the JGOFS and WOCE (Joint Global Ocean Flux Study and World Ocean Circulation Ex periment) programs have given us a first truly global survey of the physical and biogeochemical properties of the ocean. These new, high quality data provide the opportunity to better quantify the present oceans reservoirs of carbon and the changes due to fossil fuel burning. In addition, diverse process studies and time-series observations have clearly revealed the complexity of interactions between nutrient cycles, ecosystems, the carbon-cycle and the physical envi ronment.
Download or read book Marine N2 Fixation Recent Discoveries and Future Challenges written by Angela Landolfi and published by Frontiers Media SA. This book was released on 2021-04-13 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Processes and Microbes in the Marine Nitrogen Cycle written by Xin Sun and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen is an essential nutrient for all organisms on earth. Primary production in most of the surface ocean is limited by inorganic fixed nitrogen. Diverse groups of microbes transform nitrogen between fixed and gaseous forms, including the greenhouse gas and ozone-depleting agent, N2O. Oxygen concentration is a key variable in determining the fixed nitrogen budget because the loss of fixed nitrogen can only occur under low oxygen conditions, while the retention of nitrogen usually requires oxygen. Marine oxygen minimum zones (OMZs) are unique regions with a full spectrum of oxygen conditions, which allows the retention and the loss of fixed nitrogen to occur within the water column of one OMZ. Despite the small volume of OMZs, they contribute up to 30% of oceanic fixed nitrogen loss. OMZs are predicted to expand in response to climate change. Thus, quantitative information on the responses of nitrogen cycling processes to changes, especially oxygen conditions, in OMZs, is needed to accurately predict feedbacks of the marine nitrogen cycle on the global climate.This dissertation focuses on investigation of nitrogen cycling processes occurring across natural oxygen gradients in OMZs using a combination of chemical, microbiological, and modeling methods. First, the major biological sink of N2O was assumed to occur only under anoxic conditions. This dissertation showed, however, that N2O consuming microbes were present and transcriptionally active in oxygenated seawater. These microbes initiated N2O consumption rapidly after switching to anoxic conditions, and their consumption rates were much higher than those from anoxic seawaters. Second, nitrite oxidation to nitrate, which retains fixed nitrogen, is thought to be restricted to oxic environments. Surprisingly, we found two novel nitrite-oxidizing bacteria from anoxic seawaters. We also presented the first direct experimental evidence of anaerobic nitrite oxidation in samples collected from anoxic waters. Including nitrite oxidation in a biogeochemical model reduced the estimate of fixed nitrogen loss by up to 62%. Our understanding of the relationship between these two processes and oxygen must be revised by incorporating the newly discovered components of the marine nitrogen cycle and novel microbes involved in those pathways.
Download or read book The European Nitrogen Assessment written by Mark A. Sutton and published by Cambridge University Press. This book was released on 2011-04-14 with total page 665 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting the first continental-scale assessment of reactive nitrogen in the environment, this book sets the related environmental problems in context by providing a multidisciplinary introduction to the nitrogen cycle processes. Issues of upscaling from farm plot and city to national and continental scales are addressed in detail with emphasis on opportunities for better management at local to global levels. The five key societal threats posed by reactive nitrogen are assessed, providing a framework for joined-up management of the nitrogen cycle in Europe, including the first cost-benefit analysis for different reactive nitrogen forms and future scenarios. Incorporating comprehensive maps, a handy technical synopsis and a summary for policy makers, this landmark volume is an essential reference for academic researchers across a wide range of disciplines, as well as stakeholders and policy makers. It is also a valuable tool in communicating the key environmental issues and future challenges to the wider public.
Download or read book Ocean Biogeochemical Dynamics written by Jorge L. Sarmiento and published by Princeton University Press. This book was released on 2006-06-09 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ocean Biogeochemical Dynamics provides a broad theoretical framework upon which graduate students and upper-level undergraduates can formulate an understanding of the processes that control the mean concentration and distribution of biologically utilized elements and compounds in the ocean. Though it is written as a textbook, it will also be of interest to more advanced scientists as a wide-ranging synthesis of our present understanding of ocean biogeochemical processes. The first two chapters of the book provide an introductory overview of biogeochemical and physical oceanography. The next four chapters concentrate on processes at the air-sea interface, the production of organic matter in the upper ocean, the remineralization of organic matter in the water column, and the processing of organic matter in the sediments. The focus of these chapters is on analyzing the cycles of organic carbon, oxygen, and nutrients. The next three chapters round out the authors' coverage of ocean biogeochemical cycles with discussions of silica, dissolved inorganic carbon and alkalinity, and CaCO3. The final chapter discusses applications of ocean biogeochemistry to our understanding of the role of the ocean carbon cycle in interannual to decadal variability, paleoclimatology, and the anthropogenic carbon budget. The problem sets included at the end of each chapter encourage students to ask critical questions in this exciting new field. While much of the approach is mathematical, the math is at a level that should be accessible to students with a year or two of college level mathematics and/or physics.
Download or read book Denitrification in the Nitrogen Cycle written by Han Golterman and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the papers presented at a Nato Advanced Re search Workshop entitled "DENITRIFICATION IN THE N-CYCLE," held in Braunschweig (W-Germany) from 24 to 27 Mai 1983. All expenses were provided by the North Atlantic Treaty Organization. The scientific programme was in the first instance planned by some members of the Eco-Science Panel under the stimulating organization of Dr. Oscar Ravera and the final programme was prepared in co-operation between Ravera and myself. However, even during the meeting important con tributions were added. The meeting was hosted by the Microbiologi cal Dept. of F.A.L., which also took care of the organizatory as pects. Nitrate is constantly lost from both terrestial and aquatic ecosystems, causing rnixed feelings between ecologists and agricul turists. While bacteriologically very rnuch is known, the ecology of the processes is still poorly understood, nor can it be evaluated what it rneans as an econornic loss for farrners and world food produc tion. Therefore this NATO Advanced Workshop was established to per mit a lirnited nurnber of scientists active in this field to corne to gether for a short while to address the following objectives: 1) To exchange ideas between scientists (bacteriologists and ecologists) and agronornists. 2) To assess the state of the art. 3) To discuss the difficulties of experimentation in the field. 4) To define future research. In order to accornplish these objectives, the workshopwas organ ized in three parts with the following thernes: 1) Bacteriological aspects of dentrification
Download or read book Nitrogen in the Marine Environment written by and published by . This book was released on 2008 with total page 1729 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.
