Abstract. Due to their high biological productivity coastal upwelling regions are important for biogeochemical cycles in the ocean and for fisheries. Upwelled water is not only enriched in nutrients but also supersaturated with respect to atmospheric CO₂ and N₂O and undersaturated for O₂. We present a novel approach to estimate carbon based net community production (NCP) using surface ocean data for CO₂, O₂ and N₂O from three cruises to the Mauritanian upwelling region (Northwest Africa) that were conducted in different seasons. Through combination of the saturation patterns of CO₂, O₂ and N₂O effects of air–sea gas exchange and NCP could be separated. NCP values ranges from 0.6 ± 0.1g C m⁻² d⁻¹ during times of weak upwelling to 1.6 ± 0.4 g C m⁻² d⁻¹ during strong upwelling. The estimated NCP values show a strong relationship with a wind derived upwelling index, which was used to estimate annual NCP.