This study focuses on the analysis of ecosystem services associated with alternative states in the Doñana marshes. Samples were collected during 2007 and 2008 at 27 sites. They were analysed using variables related to a clear and turbid water model. Four ecosystem services were assessed: water purification, soil retention, flood control and recreation (bird watching). For each of the services, key species, functional groups, ecological processes and ecosystem functions were considered. Ecosystem service performance under the two states was assessed by quantitative measures from primary data, except for recreation where data were taken from previous research and other secondary data, considering biophysical indicators. The results describe an irregular mosaic in which clear water and turbid water states coexist, this functioning being a key condition for the maintenance of ecological functions and services. All ecosystem services analysed perform best in clear water states, where higher levels of biodiversity are also found, where macrophytes dominate. However, wetland management and restoration in the Mediterranean does not necessarily follow the same pattern.