Nitrogen cycling in a deep ocean margin sediment (Sagami Bay, Japan)

Ronnie Glud, B Thamdrup, Henrik Stahl, F Wenzhoefer, Ronnie Glud, H Nomaki, K Oguri, Niels Peter Revsbech, H Kitazato

Research output: Contribution to journalArticle

72 Citations (Scopus)

Abstract

On the basis of in situ NO3- microprofiles and chamber incubations complemented by laboratory-based assessments of anammox and denitrification we evaluate the nitrogen turnover of an ocean margin sediment at 1450-m water depth. In situ NO3- profiles horizontally separated by 12 mm reflected highly variable NO3- penetration depths, NO3- consumption rates, and nitrification. On average the turnover time of the pore-water NO3- pool was similar to 0.2 d. Net release of NH4+ during mineralization (0.95 mmol m(-2) d(-1)) sustained a net efflux of ammonia (53%), nitrification (24%), and anammox activity (23%). The sediment had a relatively high in situ net influx of NO3- (1.44 mmol m(-2) d(-1)) that balanced the N-2 production as assessed by onboard tracer experiments. N2 production was attributed to prokaryotic denitrification (59%), anammox (37%), and foraminifera-based denitrification (4%). Anammox thereby represented an important nutrient sink, but the N2 production was dominated by denitrification. Despite the fact that NO3- stored inside foraminifera represented similar to 80% of the total benthic NO3- pool, the slow intracellular NO3- turnover that, on average, sustained foraminifera metabolism for 12-52 d, contributed only to a minor extent to the overall N-2 production. The microbial activity in the surface sediment is a net nutrient sink of similar to 1.1 mmol N m(-2) d(-1), which aligns with many studies performed in coastal and shelf environments. Continental margin areas can act as significant N sinks and play an important role in regional N budgets.
Original languageEnglish
Pages (from-to)723-734
Number of pages12
JournalLIMNOL OCEANOGR
Volume54
Issue number3
DOIs
Publication statusPublished - 2009

Keywords

  • SINKING PARTICLES
  • IN-SITU
  • ANAEROBIC AMMONIUM OXIDATION
  • OXYGEN-UPTAKE
  • ESTUARINE SEDIMENT
  • ORGANIC-MATTER
  • ISOTOPE PAIRING TECHNIQUE
  • Limnology
  • Oceanography
  • MARINE-SEDIMENTS
  • CONTINENTAL-MARGIN
  • COASTAL SEDIMENT

Fingerprint Dive into the research topics of 'Nitrogen cycling in a deep ocean margin sediment (Sagami Bay, Japan)'. Together they form a unique fingerprint.

  • Cite this

    Glud, R., Thamdrup, B., Stahl, H., Wenzhoefer, F., Glud, R., Nomaki, H., Oguri, K., Revsbech, N. P., & Kitazato, H. (2009). Nitrogen cycling in a deep ocean margin sediment (Sagami Bay, Japan). LIMNOL OCEANOGR, 54(3), 723-734. https://doi.org/10.4319/lo.2009.54.3.0723