The Importance of Dissimilatory Nitrate Reduction to Ammonium (DNRA) in the Nitrogen Cycle of Coastal Ecosystems Journal Article


Authors: Giblin, Anne E.; Tobias, Craig R.; Song, Bongkeun; Weston, Nathaniel; Banta, Gary T.; Rivera-Monroy, Victor H.
Article Title: The Importance of Dissimilatory Nitrate Reduction to Ammonium (DNRA) in the Nitrogen Cycle of Coastal Ecosystems
Abstract: Until recently, it was believed that biological assimilation and gaseous nitrogen (N) loss through denitrification were the two major fates of nitrate entering or produced within most coastal ecosystems. Denitrification is often viewed as an important ecosystem service that removes reactive N from the ecosystem. However, there is a competing nitrate reduction process, dissimilatory nitrate reduction to ammonium (DNRA), that conserves N within the ecosystem. The recent application of nitrogen stable isotopes as tracers has generated growing evidence that DNRA is a major nitrogen pathway that cannot be ignored. Measurements comparing the importance of denitrification vs. DNRA in 55 coastal sites found that DNRA accounted for more than 30% of the nitrate reduction at 26 sites. DNRA was the dominant pathway at more than one-third of the sites. Understanding what controls the relative importance of denitrification and DNRA, and how the balance changes with increased nitrogen loading, is of critical importance for predicting eutrophication trajectories. Recent improvements in methods for assessing rates of DNRA have helped refine our understanding of the rates and controls of this process, but accurate measurements in vegetated sediment still remain a challenge.
Keywords: DYNAMICS; DENITRIFICATION; NITROGEN; estuary; INORGANIC; BENTHIC METABOLISM; Fringing marsh; SHALLOW; TERMINOS LAGOON; MANGROVE SEDIMENTS; C NITRITE REDUCTASE
Journal Title: Oceanography
Volume: 26
Issue: 3
ISSN: 1042-8275
Publisher: Oceanography Society  
Publication Place: ROCKVILLE; P.O. BOX 1931, ROCKVILLE, MD USA
Date Published: 2013
Start Page: 124
End Page: 131
DOI/URL:
Notes: PT: J; TC: 0; SI: SI; UT: WOS:000323808600018