Balancing act: A participatory system dynamics approach for Mar Menor’s sustainable future

• Uncoordinated policies result in ineffective interventions for the Mar Menor lagoon. • Achieving socio-economic and ecological sustainability requires coherent policies. • Leveraging collective strengths can ensure Mar Menor's sustainable future. • Long-term sustainability may need short- and medium-term socio-economic sacrifices. • Participatory modelling enhanced system insights and informed better decisions. The Mar Menor lagoon and coastal area are facing significant environmental degradation; however, the role of socio-economic activities in this crisis has been insufficiently explored. Understanding this connection is crucial for reversing the damage and ensuring sustainable development. Our research employs a participatory system dynamic modeling approach, offering a fresh perspective on the intricate interplay among environmental, social, and economic factors in the Mar Menor catchment. This method not only identifies the shared responsibilities of various economic sectors and governance levels but also highlights the critical misalignment of policies at local, regional, and national levels. By simulating different future scenarios, we demonstrate how economic sectors can collaboratively drive sustainable social-ecological interventions. This approach enables stakeholders to understand the underlying dynamics of environmental degradation and its socio-economic connections, allowing them to anticipate the medium- and long-term consequences of their actions. It can aid in creating integrated, sustainable sectoral strategies and practices. The proposed mixed strategy scenario provides actionable insights for policymakers, enabling them to develop well-aligned policies that effectively mitigate nitrate pollution and promote sustainable socio-economic growth. Moreover, this approach facilitates anticipating long-term unintended consequences, ensuring that interventions are effective. Our findings emphasize the urgent need for coordinated action and provide a clear roadmap toward improving the water quality of the Mar Menor while fostering sustainable socio-economic development in the area. By aligning policies and leveraging shared responsibilities, Mar Menor’s vital ecosystem can be safeguarded, securing a sustainable future for the region.