Effects of oxygen on recycling of biogenic elements from sediments of a stratified coastal Baltic Sea basin
Number of Authors: 5
2016 (English)In: Journal of Marine Systems, ISSN 0924-7963, E-ISSN 1879-1573, Vol. 154, 206-219 p.Article in journal (Refereed) Published
Benthic nutrient dynamics in the coastal basin Kanholmsfjarden, NW Baltic proper, were studied by in situ flux measurements and sediment samplings in 2010-2013. The benthic release of NH4 and DIP from anoxic sediments in Kanholmsfjarden were calculated to renew the standing stock inventories of DIN and DIP in the overlying water in roughly 1 year. Starting in summer 2012, mixing of oxygen-rich water into the deep part of the basin temporarily improved the oxygen conditions in the deep water. During the 1 year oxygenated period, the total phosphorus inventory in the surficial sediment increased by 0.4 g P m(-2) or 65%. This was most likely due to stimulated bacterial P assimilation under oxygenated conditions. By July 2013, the bottom water had again turned anoxic, and DIP and DSi fluxes were even higher than earlier in the study period. These high fluxes are attributed to degradation of sedimentary pools of P and Si that had accumulated during the bottom water oxygenation in 2012. The strong correlation between DIP and DSi fluxes and the similar dynamics of DIP and DSi in the sediment pore water and near bottom water, suggest a similar redox dependency of benthic-pelagic exchange for these nutrients.
Place, publisher, year, edition, pages
2016. Vol. 154, 206-219 p.
Baltic Sea, Benthic nutrient flux, Bottom water oxygenation, Sediment chemistry
Earth and Related Environmental Sciences Biological Sciences
IdentifiersURN: urn:nbn:se:su:diva-126370DOI: 10.1016/j.jmarsys.2015.10.005ISI: 000367760500007OAI: oai:DiVA.org:su-126370DiVA: diva2:903207