Download or read book Using Stable Nitrogen Isotopes to Characterize and Evaluate Nitrogen Sources to Greenwich Bay RI and Their Influence on Isotopic Signatures in Estuarine Organisms written by Peter A. Dimilla and published by . This book was released on 2006 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Science of Ecosystem based Management written by Alan Desbonnet and published by Springer Science & Business Media. This book was released on 2008-01-12 with total page 577 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the U.S., approximately two-thirds of the coastal rivers and bays are moderately to severely degraded from nutrient pollution. The contributors to this book use long-term data sets to discuss the interactions among biological, ecological, chemical, and physical processes, and discuss what is known about nutrient inputs to the bay ecosystem, the impacts related to nutrient inputs, and how the ecosystem might respond to a sudden reduction in these inputs.
Download or read book Application of Nitrogen Stable Isotopes to Identify Sources of Nutrient Pollution written by Elizabeth A. Redon and published by . This book was released on 2001 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nutrient pollution may perhaps be one of the oldest water quality problems and has recently been considered as one of the greatest threats to estuarine and coastal waters. Excessive nutrient loads have had a vast array of impacts on estuarine and coastal ecosystems globally. Direct negative effects include: shading out of benthic plant communities, hypoxia and anoxia due to increased biological oxygen demand, compositional change in plant and fauna! community structure and increased occurrences of harmful algal blooms. This has lead to decreased biodiversity, habitat, fisheries, tourism and aesthetics. So far environmental managers have had to rely on a posteriori assessments of the status of nutrient pollution, using indicators such as taxonomic shifts and changes in biological abundance, which have already occurred. By the time nutrient pollution is detected, restoration of habitats is costly and sometimes no longer an option. Therefore, there is a need for management tools to assess sources of nutrient loads before damage to estuarine and coastal ecosystems progresses beyond recovery. Early work using stable isotopes of dissolved inorganic nitrogen in groundwater samples demonstrated the potential for using stable isotopes to identify anthropogenic sources of nitrogen. These studies revealed that nitrogen sources such as fertilizers, soil organic nitrogen and wastewater nitrogen have isotopically distinct signatures that could be used to assess anthropogenic nitrogen contributions. Therefore, application of nitrogen stable isotope methods could potentially provide information on the anthropogenic nitrogen sources stimulating nutrient pollution in estuarine and coastal waters. However, when I assessed this approach for application, two sources of errors became apparent. First, laboratory isolation of dissolved inorganic nitrate from seawater delivered results depleted in 15N relative to the standard used to assess the method. Second, isotopic fractionation associated with nitrogen cycle processes complicates usage of an isotopic mass balance to solve for the nitrogen source and its fractional contribution based on isotopic data alone. As a result, isotopic analysis alone of dissolved inorganic nitrogen to determine anthropogenic sources of nutrient loads to estuarine and coastal waters is not a practical approach to obtain management information concerning nutrient pollution.
Download or read book Nitrogen Isotopes in Deep Time written by Colin Mettam and published by Cambridge University Press. This book was released on 2021-02-18 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen is an essential nutrient for life, and its sources and cycling have varied over earth history. Stable isotope ratios of nitrogen compounds (expressed as δ15N, in ‰) are preserved in the sedimentary record and track these changes, providing important insights into associated biogeochemical feedbacks. Here we review the use of nitrogen stable isotope geochemistry in unravelling the evolution of the global N cycle in deep time. We highlight difficulties with preservation, unambiguous interpretations, and local versus global effects. We end with several case studies illustrating how depositional and stratigraphic context is crucial in reliably interpreting δ15N records in ancient marine sediments, both in ancient anoxic (Archean) and more recent well oxygenated (Phanerozoic) environments.
Download or read book Stable Isotope Tracers of Nitrogen Sources to the Neuse River North Carolina written by and published by . This book was released on 1990 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Dynamics of Carbon and Nitrogen Stable Isotope Analysis of Aquatic Organisms Within the Grand River Watershed written by Heather Anne Loomer and published by . This book was released on 2008 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stable isotope analysis is a tool employed in ecological studies to provide information on the movement of elements and energy through a system. The stable carbon and nitrogen isotope analysis of aquatic organisms has been commonly used to address questions related to energy transfer between organisms and to identify the reliance of aquatic organisms on different sources of organic matter within the system. Within the rivers, stable isotope analysis has been used to describe food webs and connect conditions within the watershed with the river. The Grand River watershed is a predominantly agricultural watershed which receives inputs from ~26 MWWTP and is managed for flow by multiple large reservoirs and weirs. The stable isotope values of aquatic organisms within this watershed were analyzed from samples collected between May and September, 2007. Sites were selected in relation to three different municipal waste water treatment plants (MWWTP) in the centre of the watershed and along a 200 km stretch of the main stem of the Grand River. Results show that stable isotope analysis can be used to differentiate organisms collected from different sites and which represent different trophic levels within the river system under select conditions. Sites which are influences by inputs from organic matter or nutrients within distinct isotope values can be distinguished easily if the input is large and the isotope values are significantly distinct from background values. For smaller inputs changes in stable isotope values were not observed relative the background variability in the system. In this case, sites should be selected to allow for the characterization the variation in isotope values already occurring within the river. Samples collected later in the growing seasons have more distinctive isotope values are between sites. At sites where seasonal variation is greater, the organisms collected may not show a clear separation between trophic levels. A lack of knowledge regarding the time period represented by the tissues of the organisms challenges interpretation these results. It is concluded that stable isotope values of aquatic organisms reflected the condition of this watershed. For nitrogen increasing loads from point sources were accompanied by increasing isotope values. Stable isotope values decreased over the river reach where recovery in river condition occurs as a result of ground water inputs. The influence of individual large MWWTP and reservoirs was observable and the management of the MWWTP and reservoir appears to affect the changes in isotope values which are observed.
Download or read book Nitrogen Isotope Techniques written by Roger Knowles and published by Academic Press. This book was released on 1992-10 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the first laboratory manual to bring together basic procedures for measurement of stable and radioactive isotopes of nitrogen, with specific applications to plant, soil, and aquatic biology. This bench-top reference gives practical coverage of mass and emission spectrometry, nitrogen fixation, nitrification, and identification, organic nitrogen, and the radioactive isotope 13N. Methods are described so that researchers can adapt them, without the aid of outside references, to virtually any task they may encounter in investigations of nitrogen transformation processes. Serves as a practical guide for nitrogen isotope techniques Features studies of nitrogen transformations in terrestrial and aquatic systems Includes basic measurement techniques plus specific applications for stable and radioactive nitrogen isotopes Presents detailed protocols, overviews, and key references Includes fifty figures and sixteen tables Hands-on reference for both students and researchers
Download or read book Assessing the Use of Stable Isotopes to Monitor Anthropogenic Nitrogen Inputs to Estuarine Systems written by Rebecca O. Bannon and published by . This book was released on 2006 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stable Isotopes in Ecology and Environmental Science written by Kate Lajtha and published by Wiley-Blackwell. This book was released on 1994-08-16 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stable isotopes are used extensively in all areas of ecology: in studying metabolic processes, to monitor nitrogen turnover in soil, to look at pollution in rainwater, to trace elements through ecosystems, etc. This book, written by two of the leading researchers in the field, will explain the background to stable isotope methodology and discuss the use of the methods in varying ecological situations. An ideal resource for all ecologists using or seeking to use isotopes in their research. A complete guide to the methods, the theory behind them and their advantages and disadvantages. Adopts an ecosystem approach - unlike the competition.
Download or read book Application of Isotope Techniques for Assessing Nutrient Dynamics in River Basins written by International Atomic Energy Agency and published by IAEA Tecdoc. This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents the application of isotope techniques as a tool for evaluating nutrient dynamics in river systems. The book shows that the application of isotope techniques could enable or facilitate the examination of sources, pathways, transformations, and fates of nutrients in river systems, contributing to integrated water resource management.
Download or read book Investigation of Nitrogen Cycling Using Stable Nitrogen and Oxygen Isotopes in Narragansett Bay RI written by Courtney Elizabeth Schmidt and published by . This book was released on 2014 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Exploration of the Use of Hydrogen and Oxygen Stable Isotopes in Animal Ecology written by Nathan Wolf and published by . This book was released on 2011 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Final Report Stable Isotope Component written by P. L. Parker and published by . This book was released on 1989 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The purpose of this study was to evaluate the use of stable carbon and nitrogen isotope ratio variations for detecting and quantifying the impact of freshwater inflow on three Texas bays. The study was divided into three objectives. ... Objective 1 was accomplished and a large database reported in final reports to the Texas Water Development Board (TWDB Contracts #55-61011 and #55-71003). Objectives 2 and 3 are reported in this document"--Introduction.
Download or read book Nitrogen stable isotope ratios in surface sediments epilithon and macrophytes from upland lakes with differing nutrient status written by R I. Jones and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recovery of Nitrogen Stable Isotope Signatures in the Food Web of an Intermittently Open Estuary Following Removal of Wastewater Loads written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stable Carbon and Nitrogen Isotope Analysis written by Lindsay Ann Ecclesiastes Dorio and published by . This book was released on 2012 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stable carbon and nitrogen isotope analysis has been used to reflect dietary signatures in humans and animals. For ancient human remains, bone collagen and bone apatite are the traditional biomaterials used to estimate stable isotope ratios. For modern populations, hair and fingernail are used toward this end. Recent work indicates that dental calculus from ancient remains may be another viable biomaterial for stable isotope analysis. Because its collection is technically non-destructive, the use of dental calculus for stable isotope analysis could have benefits in cases where destructive analysis is prohibited. To help establish the utility of calculus as an isotope proxy, the present research analyzed modern calculus, along with the established biomaterials of hair and fingernail, to determine the extent to which they yield comparable isotope ratios. The analysis shows there is a strong and significant correlation between the stable carbon isotope ratios of modern calculus, hair and fingernails. In contrast, there is no correlation for stable nitrogen isotope ratios between calculus and either hair or nail. Based on the high weight percentages of carbon and nitrogen in some calculus samples, these findings may be complicated by components in plaque and saliva.
Download or read book Responding to Oil Spills in the U S Arctic Marine Environment written by National Research Council and published by National Academies Press. This book was released on 2014-08-01 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: U.S. Arctic waters north of the Bering Strait and west of the Canadian border encompass a vast area that is usually ice covered for much of the year, but is increasingly experiencing longer periods and larger areas of open water due to climate change. Sparsely inhabited with a wide variety of ecosystems found nowhere else, this region is vulnerable to damage from human activities. As oil and gas, shipping, and tourism activities increase, the possibilities of an oil spill also increase. How can we best prepare to respond to such an event in this challenging environment? Responding to Oil Spills in the U.S. Arctic Marine Environment reviews the current state of the science regarding oil spill response and environmental assessment in the Arctic region north of the Bering Strait, with emphasis on the potential impacts in U.S. waters. This report describes the unique ecosystems and environment of the Arctic and makes recommendations to provide an effective response effort in these challenging conditions. According to Responding to Oil Spills in the U.S. Arctic Marine Environment, a full range of proven oil spill response technologies is needed in order to minimize the impacts on people and sensitive ecosystems. This report identifies key oil spill research priorities, critical data and monitoring needs, mitigation strategies, and important operational and logistical issues. The Arctic acts as an integrating, regulating, and mediating component of the physical, atmospheric and cryospheric systems that govern life on Earth. Not only does the Arctic serve as regulator of many of the Earth's large-scale systems and processes, but it is also an area where choices made have substantial impact on life and choices everywhere on planet Earth. This report's recommendations will assist environmentalists, industry, state and local policymakers, and anyone interested in the future of this special region to preserve and protect it from damaging oil spills.
