The Greenpeace ship MY Esperanza and its crew are working with scientists from the German marine research institute IFM-GEOMAR to investigate ocean acidification, with the use of nine large mesocosms, or experiment water enclosures, in Kongsfjord, near the Arctic scientific research station of Ny-Alesund in Svalbard. The mesocosms are being used to investigate future implications of ocean acidification, a phenomenon caused by carbon dioxide (CO2) emissions that has just as much potential to damage marine ecosystems as climate change. Absorption of excess CO2 pollution by seawater causes its PH level to drop, making it more difficult for creatures integral to the food web to form shells and skeletons. Commenting on the success of the experiment Professor Ulf Riebesell, leader of the project said: "The experiment was successful and we have now the largest data set in our hand for impacts of ocean acidification. What we have learned from this experiment is that ocean acidification has an impact on the base of the food web, and this has implications for the entire ecosystem." The crew also tracks and documents fishing vessels from an industry exploiting this fragile ecosystem. Greenpeace is calling for the area of the Arctic Ocean historically protected year round by sea ice to be closed to all industrial activity, including destructive fishing.