Most of my PhD projects will be conducted on Askö. We are intending to follow the fate of newly fixed nitrogen (N) and carbon (C) by cyanobacterial blooms in the Baltic Sea by determining small- and large-scale N- and C-fluxes. Some of the planned projects are: I. Quantification of C- and N2-fixation in colony-forming cyanobacteria of the Baltic Sea: Combining cell-specific rate measurements with in situ abundance and size distributions of Aphanizomenon sp. and Nodularia sp. II. Remineralisation: NH4+ uptake and remineralisation as a function of POM source-leaking cyanobacteria and total NH4+ production (cyanobacteria, heterotrophic bacteria, zooplankton sloppy-feeding, detritus incl. faecal pellet production)-during cyanobacterial bloom s in the Baltic Sea. III. Remineralisation and sedimentation: O2 respiration and NH4+ production on suspended and sinking POM sources (diatoms, cyanobacteria, zooplankton detritus incl. faecal pellets) in the Baltic Sea. IV. Key processes of cyanobacterial colony-attached bacteria: Does anammox and denitrification occur in decaying Nodularia sp. colonies of the Baltic Sea? In conclusion, we are aiming to asnwer the following questions: Who are the beneficiaries of newly fixed N; and what is the fate of cyanobacterial summer blooms in terms of remineralisation and sedimentation in the Baltic Sea? Surely, we will not answer all the question during 2012, but which of these experiments will be conducted will depend on the weather condition during the stay on Askö. This PhD project is part of the BEAM researchprogramme (Baltic Ecosystem Adaptive Management) on ecosystem-based management of the Baltic Sea.

Stockholms universitet

Isabell Klawonn, Institutionen för ekologi, miljö och botanik
Handledare: Helle Ploug, Volker Brüchert