The relative proportions of marine organic carbon and biogenic carbonate in a high-resolution record from a glacial trough on the northern Norwegian continental shelf were used to decipher changes in biogenic sedimentation and paleoproductivity from the last deglaciation to the middle Holocene. Decadal-scale to century-scale oscillations in biogenic sedimentation and surface ocean productivity recorded in the Andfjorden sediments are synchronous with abrupt climate changes in open oceanic and atmospheric regimes of the high northern latitudes. Following several fluctuations during the B¿lling-Aller¿d interstadial, the most dramatic drop in marine organic carbon and biogenic carbonate proportions occurred during the Younger Dryas. However, many short-term and low-amplitude events during the Preboreal and the Holocene have also affected biogenic sedimentation in the outer Andfjorden. Apparently, these abrupt changes in biogenic sedimentation were caused by the suppression of a potential upwelling center in the outer Andfjorden by variable Atlantic Water inflow over the past 14,000 years. The adjustment of decadal high-productivity coastal systems to freshwater-forced multiple cooling events during the late glacial to middle Holocene highlights the impact of global climate changes on the climate-sensitive local ecosystems off coastal Norway.