Coupled Dynamics of Iron and Phosphorus in Sediments of an Oligotrophic Coastal Basin and the Impact of Anaerobic Oxidation of Methane
2013 (English)In: PLoS ONE, ISSN 1932-6203, Vol. 8, no 4, e62386- p.Article in journal (Refereed) Published
Studies of phosphorus (P) dynamics in surface sediments of lakes and coastal seas typically emphasize the role of coupled iron (Fe), sulfur (S) and P cycling for sediment P burial and release. Here, we show that anaerobic oxidation of methane (AOM) also may impact sediment P cycling in such systems. Using porewater and sediment profiles for sites in an oligotrophic coastal basin (Bothnian Sea), we provide evidence for the formation of Fe-bound P (possibly vivianite; Fe-3(PO4)(2)center dot 8H(2)O) below the zone of AOM with sulfate. Here, dissolved Fe2+ released from oxides is no longer scavenged by sulfide and high concentrations of both dissolved Fe2+ (>1 mM) and PO4 in the porewater allow supersaturation with respect to vivianite to be reached. Besides formation of Fe(II)-P, preservation of Fe-oxide bound P likely also contributes to permanent burial of P in Bothnian Sea sediments. Preliminary budget calculations suggest that the burial of Fe-bound P allows these sediments to act as a major sink for P from the adjacent eutrophic Baltic Proper.
Place, publisher, year, edition, pages
2013. Vol. 8, no 4, e62386- p.
Environmental Sciences Ecology
IdentifiersURN: urn:nbn:se:su:diva-90365DOI: 10.1371/journal.pone.0062386ISI: 000318008400179OAI: oai:DiVA.org:su-90365DiVA: diva2:627744