The Arctic is already experiencing consequences of climate change, with rates of ocean warming and acidification being higher than in any other of the world’s oceans. In some sense, the Kongsfjord system with its strong influence by Atlantic advection can be seen as a ‘miners’ canary’ of changes to come elsewhere in Arctic coastal systems. The effects of these changes on phytoplankton as the main primary producers and base of the pelagic food web are expected to impact ecosystem functioning and biogeochemistry. In the last four years, we have combined different observational and experimental approaches to investigate the effects of these ‘multiple stressors’ on phytoplankton assemblages and isolates from Kongsfjorden. By connecting field sampling, experiments with natural assemblages as well as detailed physiological studies of freshly isolated strains from Kongsfjorden, we aimed at understanding the ecological and physiological underpinnings of observed changes and/or resilience. In the talk, some of our approaches and their results will be presented.