Jump to main content or area navigation.

Contact Us

Extramural Research

Grantee Research Project Results

Grantee Research Project Results

Denitrification in Permeable Continental Shelf Sediments on the South Atlantic Bight

EPA Grant Number: FP916364
Title: Denitrification in Permeable Continental Shelf Sediments on the South Atlantic Bight
Investigators: Rao, Alexandra M.F.
Institution: Georgia Institute of Technology
EPA Project Officer: Just, Theodore J.
Project Period: January 1, 2004 through December 31, 2006
Project Amount: $79,609
RFA: STAR Graduate Fellowships (2004)
Research Category: Academic Fellowships , Fellowship - Oceanography and Coastal Processes , Aquatic Ecosystems

Description:

Objective:

Denitrification rates and pathways are being investigated in continental shelf sediments of the South Atlantic Bight (SAB). This region, covering 90,600 km2 on the southeastern U.S. seaboard, is dominated by permeable, nonaccumulating medium- to coarse-grained sands. Despite low organic carbon content, recent measurements have demonstrated the presence of significant metabolic activity presumably supported by filtration of organic matter advectively transported into the seabed. The objective of this study is to contribute to our understanding of the fate of fixed nitrogen in permeable shelf sediments and the potential role of continental shelves in the marine nitrogen cycle.

Approach:

Sediment flow-through reactor experiments have been conducted with unamended seawater and 15N-labelled nitrate additions to constrain the nitrogen budget for these sediments. Preliminary results indicate that denitrification occurs in the presence of oxygen, probably within suboxic microenvironments and closely coupled to in situ nitrification. Coupled nitrification-denitrification may quantitatively consume regenerated nitrogen within the upper oxic zone of SAB sediments.

Supplemental Keywords:

fellowship, South Atlantic Bight, dentrification, continental shelf, sediments, marine environments, nitrogen cycle,, RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Oceanography, Monitoring/Modeling, Ecology and Ecosystems, environmental monitoring, aquatic ecosystem, dentrification, nitrification, continental shelf sediments, ecosystem health, South AMerican Bight

Top of Page

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

Jump to main content.