Simultaneous nitrate and oxygen respiration in coastal sediments: Evidence for discrete diagenesis
Oxygen and nitrate porewater profiles from sediments of Puget Sound, the Washington continental margin, and the Chukchi Sea were determined using a whole core squeezing apparatus. The two oxidants were observed to have equal sediment penetration depths and similar profile shapes in nearly all cores. Oxygen and nitrate, therefore, behaved in a similar manner in these shallow sediments: an observation that is not consistent with existing models of sediment diagenesis. A two-dimensional model was constructed in which nearly all oxidant (O2 and NO3−) consumption took place in scattered, highly reactive discrete micro-sites. The model produced a sedimentary environment in which reactions at each micro-site were limited by oxidant concentrations with oxidant gradients extending well beyond the micro-sites into relatively nonreactive bulk sediments. Thus for a given depth surface within the sediment, oxygen concentrations were much lower at micro-sites than average concentrations on that surface. Furthermore, at most micro-sites oxygen concentrations were sufficiently low enough to permit simultaneous denitrification, which explained the apparent similarity between oxygen and nitrate concentration profiles within these sediments. The model suggests that a relatively few, short-lived reaction sites are responsible for most oxygen and nitrogen reduction within oxic sediments under shallow seas, and it is consistent with emerging concepts about the fate of organic carbon in coastal sediments.
No References for this article.
No Supplementary Data.
No Article Media
Document Type: Research Article
Publication date: September 1, 1995
More about this publication?
- The Journal of Marine Research, one of the oldest journals in American marine science, publishes peer-reviewed research articles covering a broad array of topics in physical, biological and chemical oceanography. Articles that deal with processes, as well as those that report significant observations, are welcome. Biological studies involving coupling between ecological and physical processes are preferred over those that report systematics. The editors strive always to serve authors and readers in the academic oceanographic community by publishing papers vital to the marine research in the long and rich tradition of the Sears Foundation for Marine Research. We welcome you to the Journal of Marine Research.
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Purchase The Sea
- Ingenta Connect is not responsible for the content or availability of external websites