The Mar Menor, Europe’s largest saline coastal Mediterranean lagoon in Spain’s Region of Murcia, is a natural treasure renowned for its biodiversity and cultural significance. Over the years, it faced near-collapse due to industrial and agricultural pollution, landscape changes, wastewater discharge, and invasive species. Excess nitrogen from agricultural runoff caused algal blooms, oxygen depletion, fish deaths, and the loss of seagrass, severely affecting local fisheries, tourism, and the broader regional economy.
A massive grassroots campaign involving over half a million citizens, coupled with legal action and regulatory enforcement, catalyzed the lagoon’s restoration. The Spanish Government launched the Framework of Priority Actions to Recover the Mar Menor (MAPMM), implementing 28 measures across 10 action lines. Initiatives include wetland restoration, sustainable agriculture, construction of green belts, cleanup of abandoned mining sites, flood risk management, biodiversity enhancement, and active social participation. The program targets 8,770 hectares, representing 7% of the lagoon’s basin, and aligns with Spain’s 2030 climate and biodiversity restoration goals.
Sustainable nutrient management has been a key focus, with agricultural nitrogen inputs reduced and wetlands acting as natural water filters. Local communities remain actively engaged, and the Mar Menor has been granted legal rights, making it the first European ecosystem recognized as a protected legal entity. This approach not only restores ecological balance but also generates economic benefits, with every dollar invested in ecosystem restoration estimated to return up to USD 30.
The Mar Menor example demonstrates that coordinated community action, government intervention, and investment in smart nutrient management can reverse environmental degradation. It serves as a global model for combating nitrogen pollution, supporting sustainable agriculture, and achieving broader biodiversity and climate objectives under the Kunming-Montreal Global Biodiversity Framework.
