The marine areas in the Arctic are exposed to significant climate change. This has made identification of key species and description of the area's biodiversity to a matter of urgency to make it possible to assess the likely effects of climate change and human activities in the future. Benthic fauna are mostly stationary, perennial and represent a significant proportion of marine species richness. It is therefore an ideal group to focus a baseline study on. This study of the geographic variation in the fauna diversity and determination of species distributions in Southwest Greenland complement similar ongoing and upcoming projects along the Greenland coast (MarineBasic, Kanumas West and East), which together will make it possible to give a detailed insight into the variation along a climate gradient from the sub-Arctic to the high-Arctic, as well as to identify the physicochemical and biological factors affecting the fauna. This is essential in relation to the interpretation of future variability, and also of the different time series resulting from the MarineBasic programmes.