Temporal Changes in Aquatic Ecosystem Services Provision: Approach and Examples

Marine ecosystem services are key elements to support human wellbeing. Yet, its provision is not static and may fluctuate over time as a response to ecological, social and political changes. We present a methodological approach and tool which is tailor-made to assess temporal changes in coastal and marine ecosystem services provision. The Marine Ecosystem Services Assessment Tool (MESAT) utilizes elements of the Water Framework Directive to spatially define the assessment units (water bodies) as well as temporal time slices (initial and present statuses). MESAT was applied to several water bodies in the southern Baltic Sea, including estuaries, coastal lagoons, bays and open waters. Changes in individual ecosystem services provision vary among water bodies. Nevertheless, general trends were possible to identify. The provision of the provisioning services has decreased over time, as response to anthropogenic pressures and ecological changes, and cultural services have increased significantly over time as a response to social and political changes. Regulating and Maintenance services showed no overall trends among the studied waterbodies. Assessing temporal changes can provide useful insights to managers and decision-makers by identifying trends and trade-offs between ecosystem services, as well as by highlight priority services to be restored in the future.