Offshore Freshened Groundwater, discovered in the 1960s, resides in sub-seafloor sediments and rocks, characterized by lower salinity than seawater. Globally, offshore groundwater is estimated to be between 100,000 to 1,000,000 cubic kilometers, predominantly meteoric and located near non-glaciated, passive continental margins within 50 km of the coast. However, its direct exploitation remains unexplored, primarily due to lack of data, technological and economic feasibility, environmental impacts, and legal uncertainties.
The current research landscape in Europe on the topic consists of small research groups, with very specialised skills, with limited connections between them. Fragmentation of scientific knowledge between academics with different backgrounds, and between academics and other stakeholders – hinders sharing of data, know-how and infrastructure, hampering a holistic understanding of offshore freshened groundwater, and limiting the translation of scientific findings into operational tools. Therefore there is a need for an interdisciplinary scientific effort, bringing in the perspectives and methods of a wide range of fields of research while also reflecting on the policy implications and associated regulatory framework.
To identify opportunities and priorities that could lead to the establishment of a formal JPI Oceans Joint Action on “Offshore Freshened Groundwater”, JPI Oceans hosted a scoping workshop in August 2024. The group emphasised the importance of exploring OFG, stressing the significant information gap compared to inland water resources. They further identified several promising regions for further investigation. Participants noted the need for technological innovation in OFG exploration, highlighting possible opportunities of building on existing infrastructures and of collaborating with energy sectors.
The importance of this initiative is multi-faceted. It presents an innovative approach to tackling water scarcity, particularly in coastal regions, by exploring offshore groundwater as a freshwater source. This exploration is expected to lessen the environmental impacts associated with traditional water resources and can provide a buffer to increased demand during periods of intense drought. Importantly, it bridges the gap between science, policy, and society, ensuring that potential exploration aligns with responsible environmental and societal norms.