The Arctic region is rapidly warming. As a result of the sea ice retreat the area is opening up for human activities, leading to pressures on the marine environment. This thesis assesses two pressures of local human activities on the marine coastal system of Svalbard: contaminants and non-indigenous species. Results from field studies focusing on the present situation are combined with data from laboratory studies that are needed to prepare for potential future pressures. This information forms the basis for an assessment of risks for the Svalbard marine coastal system and is of vital importance for the proper management of anthropogenic activities in a changing Arctic coastal system.