Ecosystem status and indicators: the way it can, should and will work!

The main policy goals of the Water Framework Directive (WFD) & Marine Strategy Framework Directive (MSFD) are to reach a good status of the marine ecosystem, implying that human activities have to be performed in a sustainable way. Indicators are the scientific response to the governmental need for reliable and accurate information on the conditions or so-called ‘status’ of the ecosystem. Due to the complexity of aquatic ecosystems, several indicators with complementary properties are needed to effectively support the decision-making process (Van Hoey et al., 2013). However, the delineation of an appropriate set of indicators still remains a major challenge. Both WFD and MSFD follow different strategies and EU member states are defining separate sets of indicators for either directive. Major discrepancies between directives and member states are related to: (1) differences in available research experience (and data availability) between member states, (2) lack of a common implementation strategy (several indicator types for the same ecosystem component and descriptor), (3) the degree of risk and uncertainty each authority is prepared to accept, and (4) the interpretation of the term ‘good status’. The WFD strategy allows each member state to define its own set of indicators, and adheres to multiple intercalibration exercises to evaluate the compatibility between the different indicators. Currently, the inter-calibration for the North East Atlantic (NEA) region is in its 3th phase (JPI oceans pilot action) and shows that, for example for the benthic ecosystem component in coastal waters an inter-calibration for the 10 existing and selected benthic indicators is feasible, be it a long-winded road to get there. On the contrary, the MSFD strategy strives towards common indicators on a regional scale instead of inter-calibrating the existing or proposed ones. This development process is carried out by a variety of EC, OSPAR and ICES working groups, none of them with real ‘political’ power to take decisions on the implementation at EU (or regional) scale. This has led to even more pronounced discrepancies compared to the WFD process. For example, a comparison of 45 benthic indicators for soft sediments in the NEA region proved to be chaotic, full of vague approaches, with only a weak link to the WFD indicators. Moreover, this whole comparison exercise is continuously struggling with the varying ambitions of the different authorities and member states. There is still a long way to go, yet both WFD and MSFD processes already largely increased our knowledge on the application of indicators in marine management. The different processes show us how it can and should work, and slowly lead us in the right direction of a common assessment of the ecosystem status by means of a widely accepted and appropriate set of indicators.