EU request for a technical service to scope the knowledge base and the analytical and governance frameworks for seafloor quality threshold setting

<p dir="ltr">The Workshop on Scoping Input to Inform Seafloor Quality Threshold Setting (WKD6SCOPE) was convened to advance the development of scientifically sound and operational methods for defining thresholds that support the achievement of Good Environmental Status (GES) under the Marine Strategy Framework Directive (MSFD). Requested by the European Commission (DG Environment), the workshop contributes to ICES work on assessing seafloor condition (Descriptor 6 C5) by building shared understanding of threshold-setting methods and their governance context.</p><p dir="ltr">The workshop addressed two overarching questions: (i) which threshold-setting methods and indicators are most suitable for use in the ICES analysis and advice process? and (ii) how can these methods be adapted and applied to ensure both scientific credibility and policy relevance?</p><p><br></p><p dir="ltr">Participants reviewed and compared 11 threshold-setting approaches, of which “natural variation”, “distance to degradation”, “detectable change”, and “breakpoints with quartile regression” were considered most promising and selected for application during the coming threshold-setting process. Approaches were considered along with different applications of these methods to better address data gaps and uncertainties in pressure–state relationships. Participants found broad agreement to come to an assessment based on the data from existing monitoring. They further agreed that, by applying multiple threshold-setting methods across several indicators, the impact of key bottlenecks—i.e. lack of undisturbed reference data, unclear pressure-state responses, and overall data scarcity—could be reduced. The simultaneous application of multiple methods or the use of a decision tree is expected to improve confidence and comparability of threshold-setting methods. Using a range of ecological indicators—including those reflecting sensitive species, community biomass, and benthic diversity—is considered important to capture the complexity of benthic ecosystems and their differing sensitivities to pressures such as abrasion, nutrient enrichment, and hypoxia.</p><p dir="ltr">WKD6SCOPE will be delivered as a Technical Service to the European Commission (DG Environment). Outcomes will inform the upcoming ICES data analysis phase that has been requested. Data from the ICES data call will be analysed through documented workflows and reproducible scripts, ensuring transparency and repeatability. This workflow will allow others, e.g. scientists from Member States, to re-run analyses conducted within the ICES workshop, apply the methods in national assessments, and promote transparency in the process of setting thresholds.</p><p dir="ltr">Discussions in WKD6SCOPE addressed the governance and legal dimensions of threshold setting under the MSFD. Member States are required to use thresholds—once established through EU or regional cooperation—in their determination of GES. This means that Member States must then assess GES according to these threshold values and, if they fail to achieve them, take the appropriate measures and management decisions to reach the thresholds. The societal acceptance of these thresholds depends on transparency, inclusiveness, and the traceability of the scientific reasoning underpinning them. WKD6SCOPE emphasized that thresholds serve as both scientific and governance tools, by translating environmental assessments into policy and adaptive management actions within the ecosystem-based approach of the MSFD.</p><p dir="ltr">Applying MSFD seafloor thresholds also offers strong synergies with the Nature Restoration Regulation (NRR). Thresholds help identify where benthic disturbance should be reduced or restoration prioritized, ensuring coherence across EU marine policy frameworks.</p><p dir="ltr">Future work could focus on testing and refining the proposed methods with available data; improving understanding of uncertainty; and ensuring alignment of MSFD thresholds with related legislation, regional sea conventions, and other stakeholders.</p><p dir="ltr">In addition to the above executive summary, the full scoping workshop report is available in the ICES library: <a href="https://doi.org/10.17895/ices.pub.30426775" rel="noreferrer" target="_blank">https://doi.org/10.17895/ices.pub.30426775</a> </p>