Sources and sinks of nitrogen in the Cape Fear River estuary, southeastern North Carolina

UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
Leslie C. Bradshaw (Creator)
The University of North Carolina Wilmington (UNCW )
Web Site:
Steven Skrabal

Abstract: Fluxes of NH4+, NO3-, free amino acids, total nitrogen (TN), and organic nitrogen (ON) were measured in core incubation and particle exchange experiments between September 2002 and April 2004. These data were combined with other measurements of nitrogen species in river water, atmospheric deposition and wastewater discharge in order to determine nitrogen (N) speciation and loading to the Cape Fear River Estuary (CFRE), Southeastern North Carolina, and to ascertain why NH4+ concentrations in the estuary have more than doubled in the past 8 years. River fluxes are the primary source of N into the estuary, contributing >90% of TN input. The majority of N in river fluxes was ON (84%), with the remainder being inorganic N, primarily NO3- (11%) and NH4+ (5%). Sediments are also a source of the various N species to the estuary although they are much smaller than riverine inputs. The majority of TDN in benthic fluxes is dissolved inorganic N (50 to 90%) with NH4+ generally dominating the fluxes. Benthic fluxes of dissolved organic N are somewhat smaller (-1500 to 200 µmols DON·m-2·d-1) and are primarily taken up by sediments in contrast to inorganic N, which is generally released by sediments. Wastewater treatment discharge is a secondary source to river fluxes for TN where it contributed <5% to the annual TN input. Inorganic N was a major portion in discharge fluxes, with NH4+ making up 65% of TN. Although wastewater inputs are not important for TN, they are an important source of NH4+, contributing 33% to the total NH4+ input in the CFRE.

Additional Information

A Thesis Submitted to the University of North Carolina Wilmington in Partial Fulfillment Of the Requirements for the Degree of Master of Science
Language: English
Date: 2009
Water--Nitrogen content--North Carolina--Cape Fear River, Estuaries--Environmental aspects--Research--North Carolina--Cape Fear River, Nitrates--Environmental aspects--North Carolina--Cape Fear River, Nitrogen--Environmental aspects--North Carolina--Cape Fear River
Water -- Nitrogen content -- North Carolina -- Cape Fear River
Nitrates -- Environmental aspects -- North Carolina -- Cape Fear River
Estuaries -- Environmental aspects -- Research -- North Carolina -- Cape Fear River
Nitrogen -- Environmental aspects -- North Carolina -- Cape Fear River

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