During the two last decades, groundwater ecology has developed very rapidly as a new research area. Groundwater ecology originated important concepts such as Groundwater Dependent Ecosystems. Recent studies have concluded that many of the Earth's ecosystem services are seriously affected by over-use and abstraction of groundwater resources. All these anthropogenic changes pose a significant threat to the health of the groundwater dependent ecosystems and negative modifications on the services provided by them. The book, authored by specialists in the field, presents relevant papers on climate changes, groundwater quantity and quality and threatening processes in dependent ecosystems, biological aspects of groundwater dependent ecosystems and management and economic tools to protect groundwater.