Mapping groundwater aquifers located more than 400 metres beneath the seabed in the coastal area between Jesolo and Lignano. This was the objective of the recently completed oceanographic expedition carried out under the RESCUE project aboard the Laura Bassi research vessel of the National Institute of Oceanography and Applied Geophysics (OGS).

Coordinated by the University of Trieste, with OGS as a project partner, RESCUE aims to strengthen water security through research and innovation by identifying freshwater resources in unexplored coastal and offshore aquifers. Building on recent scientific discoveries, the project is mapping deep, low-salinity aquifers—located at depths exceeding 400 metres—both on land and beneath the seabed. At a time when freshwater resources in coastal regions are increasingly threatened by population growth, pollution and climate change, these aquifers could help supplement water supplies for drinking, agriculture and industry, while also reducing the costs associated with seawater desalination.

Researchers and students from OGS, the University of Trieste, the University of Pisa, CNR-ISMAR (Institute of Marine Sciences of the Italian National Research Council) in Bologna, the University of Malta, and the Monterey Bay Aquarium Research Institute (MBARI, California, USA) took part in the expedition aboard the Laura Bassi.

During the campaign, researchers carried out seismic reflection surveys to obtain high-resolution images of the subsurface beneath the seabed, together with seafloor mapping. In addition, electromagnetic surveys were conducted for the first time in the area to detect the possible presence of freshwater aquifers beneath the seabed. The investigations, which did not involve any seabed sampling, covered an area approximately 10 kilometres offshore, extending from Jesolo, in the Province of Venice, to the Tagliamento Delta off the coast of Lignano.

"The surveys were carried out under excellent environmental conditions, and all operations proceeded according to plan. The data collected are of very high quality, but several months of laboratory processing and analysis will be required before we can confirm the presence of freshwater aquifers beneath the northern Adriatic seabed," said Cristina Corradin, OGS researcher and scientific coordinator of the expedition.

"The operations required the integration of several geophysical techniques and close collaboration among the different research teams, the technical and scientific staff, and the ship's crew," explained Daniela Accettella of OGS, chief scientist aboard the Laura Bassi.

"After two years of scientific work, the RESCUE team has successfully applied innovative integrated geophysical methods for investigating deep offshore aquifers in one of the most promising study areas: the seabed of the northern Adriatic, particularly off the coast of Friuli Venezia Giulia. The new data will improve our understanding of regional groundwater resources and contribute to addressing water shortages linked to climate change and extreme events, such as the heatwave and drought currently affecting Europe," said Professor Michele Pipan of the University of Trieste, coordinator of the RESCUE project.

This oceanographic expedition has also laid the groundwork for a second research initiative funded by the European intergovernmental association JPI Oceans. Launched through a joint initiative by Malta and Italy, the new project will seek to confirm the presence of freshwater beneath the northern Adriatic seabed by drilling an offshore scientific borehole—the first of its kind in Europe. The project is coordinated by the University of Malta and involves OGS, the University of Trieste, the Alto Adriatico Technology Hub, as well as research institutions from Germany and Greece. It is funded by the Italian Ministry of University and Research (MUR) and the Autonomous Region of Friuli Venezia Giulia.

RESCUE – Resources in Coastal Groundwater Under Hydroclimatic Extremes is a project co-funded by the Water4All Partnership and the European Union. It addresses water scarcity in coastal regions by investigating deep groundwater resources located both onshore and beneath the seabed. The project focuses on mapping these resources, assessing their long-term sustainability, and developing policy recommendations for their sustainable use.

The project is coordinated by the University of Trieste, with OGS as a partner. Other partners include the University of Derby (United Kingdom), Ruden AS (Norway), and the University of Malta.