In this presentation, we will discuss how saltwater intrusion affects small islands freshwater supplies, and how tourism is a significant part of this. In Zanzibar fresh water for drinking and other purposes come from rain that replenishes the island’s groundwater reservoir and in many cases freshwater is a scarce resource. On top of this, the excessive pumping in groundwater for the tourist industry increases the risk of salt water seeping into the freshwater magazine from the sea, thereby destroying the freshwater resource. Would you like to learn more about Sustainable Tourism? Sign up for our online course: Sustainable Tourism - promoting Environmental Public Health? (indsæt hyperlink over titel, hvis muligt https://www.coursera.org/learn/sustainable-tourism You are also welcome to join other MOOCs from University of Copenhagen. (indsæt hyperlink, hvis muligt https://coursera.org/ucph). Flemming Konradsen Professor, Director, School of Global Health, University of Copenhagen