In this article of the REMENA policy paper series, Bdredin Suliman, Hussam Hussein and Salma Daoudi  explore the impact of desalination on the Mediterranean ecosystem. Desalination, the process of purifying brackish or seawater to provide freshwater, has gained prominence globally and is particularly crucial in regions facing water shortages. The paper highlights the positive aspects of desalination, such as diversifying water sources and supporting economic growth in water-stressed areas. However, it also underscores the challenges associated with this technology, including high energy consumption and environmental concerns linked to the disposal of concentrated brine into the sea.

 The Mediterranean region, characterized by diverse countries facing water scarcity, has become a hub for desalination projects. The paper points out that while technological advancements, such as reverse osmosis and renewable energy integration, aim to improve efficiency and reduce environmental impact, challenges persist. The authors stress the importance of managing water supply strategies and promoting regional cooperation to minimize the environmental footprint of desalination.

The Mediterranean faces a growing water demand, with projections indicating a doubling or tripling of water demand by 2050. The paper emphasizes that desalination has become an essential component of the region's water supply portfolio, especially in the face of climate change impacts and water stress. The authors discuss the concentration of desalination plants in countries like Spain, Italy, Israel, Cyprus, Algeria, and Malta.

Despite the potential benefits, the paper outlines various challenges associated with desalination, including economic, ecological, and political obstacles. High energy requirements mostly covered by fossil fuels, financial costs, and habitat disruption are identified as sustainability concerns. The paper delves into the ecological impacts of desalination on marine ecosystems, noting adverse effects on biodiversity, fish populations, and the release of concentrated brine. It emphasizes the need for continuous research, environmental monitoring, and technological advancements to mitigate these negative effects. Geopolitical tensions and a lack of regional cooperation further complicate the sustainable implementation of desalination projects.

In terms of policy implications and recommendations, the authors propose measures such as promoting international cooperation frameworks, strengthening regional collaboration, and focusing on sustainable water management. They advocate for enhanced environmental impact assessments, effective brine disposal management, and investment in technological innovation to improve desalination procedures. The paper concludes that while desalination offers a    potential solution to water scarcity, careful consideration and strategic policies are necessary to address the associated challenges and ensure long-term sustainability.