Cyanobacteria as a trigger for increased primary productivity during sapropel formation in the Baltic Sea: a study of the Ancylus/Litorina transition
2007 (English)In: Journal of Paleolimnology, ISSN 0921-2728, E-ISSN 1573-0417, Vol. 38, no 1, 1-12 p.Article in journal (Refereed) Published
A sediment sequence from the Gotland Basin, representing the Ancylus Lake/Litorina Sea transition, was analysed for pigments, stable isotopes (δ13C and δ15N), diatoms and carbon and nitrogen content. The negative correlation between the cyanobacterial specific pigment zeaxanthin and δ15N supports the hypothesis that cyanobacteria in the early Litorina Sea indeed were nitrogen fixers. Their incorporation of nitrogen could have acted as a trigger for eutrophication during the Litorina Sea stage of the Baltic Sea. As cyanobacteria normally flourish in eutrophicated waters, the increasing concentrations of zeaxanthin during early Litorina Sea also corroborate that high primary production was an important part of the formation of organic rich (sapropel) sediments in the Baltic Sea. The first occurrence pre-dates the formation of laminated sediments, but the peaks of both zeaxanthin and organic carbon are within laminated sequences. This implies that the oxygen conditions of the bottom water also play a major role in the formation of sapropel sediments.
Place, publisher, year, edition, pages
2007. Vol. 38, no 1, 1-12 p.
Sapropels - Baltic Sea - Primary production - Cyanobacteria - Pigments - Zeaxanthin
IdentifiersURN: urn:nbn:se:su:diva-25827DOI: 10.1007/s10933-006-9055-0ISI: 000247530100001OAI: oai:DiVA.org:su-25827DiVA: diva2:200608
Part of urn:nbn:se:su:diva-8952006-03-022006-03-022010-07-27Bibliographically approved