Macrofaunal Effects on Nitrification and its Coupling to    Denitrification in Coastal Marine Sediments
{'Code': '06040301', 'Directorate': {'Abbreviation': 'GEO', 'LongName': 'Directorate For Geosciences'}, 'Division': {'Abbreviation': 'OCE', 'LongName': 'Division Of Ocean Sciences'}}
{'SignBlockName': 'Phillip R. Taylor', 'PO_EMAI': None, 'PO_PHON': None}
This study examines the interaction between benthic                        macrofauna and sediment nitrification and denitrification in                    the coastal marine environment.  Dr. Kemp and his co-inves-                     tigator Dr. Boynton will make direct measurements of                            macrofaunal influence on nitrification and coupled                              nitrification - denitrification using a modified 15N                            isotope technique for intact coastal marine sediments with                      manipulated animal densities.  Three levels of                                  macrofaunal abundance will be used for representative                           species (e.g. amphipod, bivalve, polychaete).  Alternative                      mechanisms by which macrofauna may stimulate nitrification                      (e.g. increased supplies of oxygen vs. ammonium) will be                        examined separately using artificial tubes will be compared                     using microelectrode techniques.  Three possible mechanisms                     for macrofaunal enhancement of nitrification - denitrification                  coupling will be tested with the isotopic procedures                            including: 1) effects of radial diffusion geometry; 2) effects                  of alternating oxic- anoxic conditions; 3) role of anoxic                       microsites in surface deposited fecal pellets.                                       Dissolved nitrogen compounds such as nitrate and ammonium                  are important nutrients for biological production.  However,                    the oxidation of ammonium (nitrification) coupled to the                        reduction of nitrate to nitrogen gas (denitrification) results                  in the decrease of nitrogen in biologically active pools and                    may serve one of the important mechanisms controlling the                       nutrient levels in sea water.  This study addresses the                         coupling of these processes and their relation to the larger                    organisms living in the coastal sediments, an environment                       in which nitrification/denitrication is particularly active.                    The work will test quantitatively the notion that the                           sediment burrows these organisms construct (along with the                      activities of these animals) facilitates the microbiological                    nitrification/denitrification activity in the surrounding                       sediment.  The work include novel experiments using                             sediment samples with varying numbers of organisms and                          laboratory experiments using artificial burrows.  Isotopic                      labelling experiments will be used to measure the actual                        rates of nitrification/denitrification and to address the                       mechanisms by which the larger sediment organisms influence                     these microbiological processess.
{'FirstName': 'William', 'LastName': 'Kemp', 'PI_MID_INIT': 'M', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'William M Kemp', 'EmailAddress': 'kemp@hpl.umces.edu', 'NSF_ID': '000117713', 'StartDate': '01/01/1989', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'University of Maryland Center for Environmental Sciences', 'CityName': 'CAMBRIDGE', 'ZipCode': '216133368', 'PhoneNumber': '4102212014', 'StreetAddress': '2020 HORNS POINT RD', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Maryland', 'StateCode': 'MD', 'CONGRESSDISTRICT': '01', 'CONGRESS_DISTRICT_ORG': 'MD01', 'ORG_UEI_NUM': 'JHTYTGKYWLL9', 'ORG_LGL_BUS_NAME': 'UNIVERSITY OF MARYLAND CENTER FOR ENVIRONMENTAL SCIENCE', 'ORG_PRNT_UEI_NUM': None}
{'Name': None, 'CityName': None, 'StateCode': None, 'ZipCode': None, 'StreetAddress': None, 'CountryCode': None, 'CountryName': None, 'StateName': None, 'CountryFlag': None, 'CONGRESSDISTRICT': None, 'CONGRESS_DISTRICT_PERF': '""'}
[{'Code': '1650', 'Text': 'BIOLOGICAL OCEANOGRAPHY'}, {'Code': '1670', 'Text': 'Chemical Oceanography'}]
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1988&All=true', 'xml': '8811269.xml'}