Zero pollution

Further details on the systemic and synthesis for this European Green Deal Criterion are available in the MERLIN Deliverable Report page 75.

We note that few studies considered Zero Pollution as a relevant restoration objective. The use of multiple sub-indicators, or specific indicators was a particular consideration in the synthesis analysis for Zero Pollution complicating a meta-statistical approach to explore commonality in responses across indicator types. For example, Sub-Indicator Unique Identification Codes were highly variable for many determinants, likely representing the lack of a consistent terminology used by reporting laboratories. For this reason, the analysis presented here considers site responses independently of each other. Most case studies did not employ a full Before-After-Control-Impact study design.

In the Peatland and Wetland Cluster three of the case studies were assessed as having negative impacts reported for Zero Pollution, albeit with low levels of confidence. The reasons behind these negative impact assessments are variable and include mobilisation of sediments and silts during the implementation of restoration measures and changes in nutrient concentrations because of changes in connectivity.