Organic carbon fluxes in polar oceans: Subject to changing ice conditions and related secondary effects

Primary production and mineralization are key processes and living organisms key components of the biological carbon cycle. Their dynamics are controlled by abiotic and biotic factors, which can also be inter-dependently linked with each other. Changes in the polar cryosphere and related secondary effects, associated with global temperature increase, can have a great impact on processes and components of the biological carbon cycle. For example, nutrients and particles are released into the marine realm by glacial and permafrost soil melt, while thinning, diminishing, and retreating sea ice leads to increased light availability but suppresses nutrient upwelling. These secondary effects are known to influence primary productivity, organismal community structures and mineralization rates. The investigation of how changes in polar ice conditions alter primary production, the benthic biota, and benthic mineralization is the overall aim of this thesis and was addressed in three manuscripts.