Estuaries are very vulnerable systems to climate change, especially with rising sea levels. For this reason, they are a priority objective in conservation, restoration and adaptation strategies to climate change.

In this context, the Foundation Institute of Environmental Hydraulics of Cantabria (FIHAC), with the support of the Biodiversity Foundation, has promoted the project “Preparation of Risk Maps of natural systems in the face of climate change in the Cantabrian estuaries (MARES)”.

In the MARES project, flooding in 4 Cantabrian estuaries has been characterised under 5 climate change scenarios. Based on this information, the impact of flooding on the 39 habitats identified in the estuary and adjacent coastal areas has been estimated, and on theirability to provide 31 supply, regulatory and cultural services on which human well-being depends. To this end, a specific methodology has been developed that allows these consequences to be evaluated in biophysical and economic terms for 25 ecosystem services. The results obtained reveal that estuaries are complex socio-ecological systems with a high ecological, social and economic value and that climate change will have economic consequences on the provision of ecosystem services that will be directly proportional to the extension of the flooded area and the increase in the water column. Based on the results obtained, a proposal for measures to manage the estuary ecosystem and the services they provide in a context of climate change has been developed.