Change search
ReferencesLink to record
Permanent link

Direct link
Sedimentary phosphorus dynamics and the evolution of bottom-water hypoxia: A coupled benthic-pelagic model of a coastal system
Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
2011 (English)In: Limnology and Oceanography, ISSN 0024-3590, Vol. 56, no 3, 1075-1092 p.Article in journal (Refereed) Published
Abstract [en]

The present study examines oxygen and phosphorus dynamics at a seasonally hypoxic site in the Arkona basin of the Baltic Sea. A coupled benthic-pelagic reactive-transport model is used to describe the evolution of bottom-water solute concentrations, as well as pore-water and sediment profiles. Aerobic respiration dominates remineralization, with iron reduction, denitrification, and sulphate reduction playing secondary roles, while other pathways are negligible. Sediments represent a significant oxygen sink chiefly due to the aerobic degradation of organic matter, as well as nitrification and iron oxyhydroxide precipitation. Most phosphorus deposited in sediments is in organic matter, yet cycling is dominated by iron-bound phosphorus due to rapid dissimilatory iron reduction coupled with aerobic iron oxyhydroxide formation. Sustained hypoxia results in an initial decrease in sediment phosphorus content due to dissolution of phosphorus-bearing iron oxyhydroxides, resulting in a pulse of phosphate to overlying waters. Although an organic-rich layer is formed under low-oxygen conditions, enhanced remineralization of organic phosphorus relative to organic carbon tempers sedimentary phosphorus accumulation. Upon reoxygenation of bottom waters after a decade of sustained hypoxia, oxygen concentrations do not immediately achieve values observed prior to hypoxia because the organic-rich layer creates a higher benthic oxygen demand. Artificial reoxygenation of bottom waters leads to a substantial increase in the iron-bound phosphorus pool; the total phosphorus content of the sediment, however, is unaffected. A relapse into hypoxia would consequently produce a large pulse of phosphate to the overlying waters potentially exacerbating the situation.

Place, publisher, year, edition, pages
2011. Vol. 56, no 3, 1075-1092 p.
National Category
Natural Sciences
URN: urn:nbn:se:su:diva-68508DOI: 10.4319/lo.2011.56.3.1075ISI: 000290678100025OAI: diva2:473695
authorCount :3Available from: 2012-01-07 Created: 2012-01-04 Last updated: 2012-01-07Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Gustafsson, Bo G.
By organisation
Baltic Nest Institute
In the same journal
Limnology and Oceanography
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 99 hits
ReferencesLink to record
Permanent link

Direct link