The Marine Ecosystem Services Assessment Tool (MESAT) was developed to address the knowledge gap regarding the assessment of ES in coastal and marine environments. It assesses changes in ES provision between two points in time (an initial/past and a present status) and can be applied in a qualitative (expert-based) or in a semi-quantitative (data-based) way.
It is based on CICES and includes 31 ES, assessed by 54 indicators. The indicators are assessed for both points in time (usually representing a time period of 5 years to reduce the effects of annual variations). The difference between the indicator values are allocated into a numerical scale with logarithmic increase. It has 11 categories of change (CC): five positive (“1.1 to 1.3”, “1.3 to 1.7”, “1.7 to 2.5”, “2.5 to 4.1” and “>4.1”), five negative (“-1.1 to -1.3”, “-1.3 to -1.7”, …, “<-4.1”) and one class representing no change (“-1.1 to 1.1”). Each indicator value for the initial status is multiplied by the category borders to give the range of values defining each category of change. The user then compares the value of the indicator for the present status with the intervals and for each category of change and assigns the corresponding CC. For representation purposes, the scale is simplified to “1 to 5” representing an increase in ES provision, “-1 to -5” representing a decrease in ES provision” and “0” representing no changes.
The tool automatically generates graphical outputs for different CICES hierarchical levels. For the data collection, different sources such as empirical data (databases), reports and scientific literature, other sources such as model outputs and internet sources, and expert knowledge can be used.
Within Coastal Management and SAF MESAT can be applied to: