Threshold methodology and value for the assessment of Good Environmental Status of D2C1 'Newly-introduced non-indigenous species'

The report provides recommendations for an operational definition of Good Environmental Status (GES) for the Marine Strategy Framework Directive (MSFD) criterion 'newly introduced Non-Indigenous Species (NIS)', along with a data plan for each marine region and subregions, and a methodological protocol for the analysis of the threshold values. - The data collection involved aggregation from various sources, including the European Alien Species Information Network (EASIN), AquaNIS, and peer-reviewed literature. This was a lengthy process, which involved several marine biologic invasion experts with the aim to ensure the data quality and a common understanding of species to be considered in GES reporting and assessment. - The Commission Decision (EU) 2017/848 states the number of NIS should be minimized as much as possible or reduced to zero, guiding the proposed threshold values. - Member States (MS) are recommended to consider the recommendations in this report to inform decisions on regional and subregional threshold values for D2C1. - This report provides guidance for decision-making on the management of NIS to protect marine environments.