Background Freshwater ecosystems are very important in terms of the number and variety of species they host. Groundwater, including more than 70% of the Earth's fresh water, plays a crucial role in the maintenance of most surface environments and has profound implications for human well-being and socio-economic development. Groundwater environments are also among the most important corridors, connecting different kinds of other freshwater environments, including lakes, rivers, springs and wetlands. In the European Union, all of these systems and their biodiversity are highly threatened. Consequently, the Groundwater Daughter Directive (2006/118/EC) underlines the importance of protective measures for groundwater ecosystems in its introductory section, and in further notes. However, awareness of groundwater as a biological habitat has lagged behind awareness of its importance as a drinking water reservoir. As a consequence, no comprehensive indicator systems for the evaluation of biodiversity levels and losses in groundwater-dependent ecosystems are available. Objectives The project will develop and disseminate the AQUALIFE Package, which will be an innovative and user-friendly work package of biodiversity indicators that will be easily and widely useable for assessing the status of biodiversity and biodiversity losses in groundwater-dependent ecosystems (hereafter GDEs). The AQUALIFE Package will fill an identified gap, as no similar indicator systems currently exist. The specific objectives of the project are: To develop and test a new set of indicators for assessing and mapping biodiversity status, trends and losses in GDEs; To produce the user-friendly AQUALIFE work package and to disseminate it to people who are potentially interested in its use for monitoring GDEs, management planning and the development of field interventions. Expected results: A first-level database will be assembled, gathering all the background information about the distribution of groundwater, drivers, pressures and impacts affecting GDE biodiversity, and including data gathered from 70 sampling sites; A schematic table, with an annex describing the statistical methodology used and the criteria adopted for calculating the measured level of biodiversity at the monitored sampling sites, will be drawn up, accompanied by a methodology for extrapolating biodiversity losses and applying the results to other Italian regions and EU countries; A relational database will be established. Database users will be able to access the data in an almost unlimited number of ways, and to combine the tables as building blocks to create complex and much larger databases; A validation procedure will be carried out covering an additional 20 testing sites, the results of which will be used to fine tune the indicator system and extend its application; The AQUALIFE Package will be produced and distributed to at least 250 relevant people in public and private institutions and NGOs.