Evidence from the eight AQUACROSS case studies shows that ecosystem-based management approaches are more effective in reaching biodiversity targets while involving lesser costs. In particular the explicit consideration of trade-offs between ecosystem services (e.g. flood retention, recreation, or biomass production) allows improving biodiversity conservation while conserving economic activities.

Ecosystem—based management (EBM) is a promising approach which supports the implementation of the EU biodiversity strategy. EBM can be captured through several key components, which include for example the consideration of ecological integrity and resilience, the use of multi-disciplinary knowledge, stakeholder participation or policy coordination. During the project duration, AQUACROSS case studies advanced on several of these components. As a result, case studies have developed tailored EBM plans, consisting of alternative management measures and policy instruments for an improved implementation of the EU biodiversity strategy.

EBM is a cyclical approach, which implies that proposed management options are continuously evaluated and adapted. The AQUACROSS framework foresees an evaluation of EBM plans for at least three criteria: their effectiveness in reaching environmental targets, the comparison of costs and benefits (i.e. the evaluation of efficiency), and their effects in terms of equity and fairness. The evaluation exercise can include the use of models and quantitative approaches, as well as more qualitative descriptions of the impacts.

The evaluation undertaken within AQUACROSS shows that EBM approaches are both more effective in reaching environmental targets, and more efficient (i.e. increasing human wellbeing). This is shown for example for the Danube case study. The added value of EBM lies amongst others in the more comprehensive perspective which is taken on the existing ecological and social system, which tries to identify all important links between nature and society. Furthermore, the resulting proposition of multi-purpose measures, which help reaching different societal objectives at once, is another key output of EBM. The consideration of trade-offs between ecosystem services, together with the involvement of stakeholders, allows the creation of a transparent basis for decision making. It strengthens furthermore reflections on equity and fairness implications of different management approaches among different groups of the society.

In terms of enabling factors for EBM, the existence of institutions which allow for effective coordination among different policy domains (e.g. nature conservation, water management, agriculture, etc.) is an important precondition for a successful implementation of EBM and its contribution to the EU biodiversity targets. The same applies to the need for decision-makers to be open minded for management measures, which are different than the ones they are used to (i.e. nature-based, multipurpose), as well as to the importance of taking stock of knowledge from different scientific domains (natural and social science).

The full Evaluation of Ecosystem-Based Management Responses in Case Studies and its Executive Summary are available online.

Photo: Danube River connected sidearm, Andrea Funk