Global Characterization Factors for Seabed Biodiversity Loss: A New Framework for Marine Impact Assessment

Quantifying biodiversity impacts along global value chains is essential for achieving the Kunming-Montreal Global Biodiversity Framework’s Targets 15 and 16, which call for corporate disclosure of biodiversity impacts and informed, sustainable consumption. Yet despite growing attention to terrestrial and freshwater systems, consistent methods to capture marine biodiversity impacts remain underdeveloped. Seabed damage is a top driver of marine biodiversity loss, but no globally applicable model exists for quantifying seabed damage impacts from anthropogenic systems. In our study, we develop the first global-scale characterization model for seabed biodiversity loss caused by the two main mechanisms of action - abrasion and extraction - resulting in characterization factors (CFs) at both the marine ecoregion (coastal) and FAO fishing area (open ocean) level. We focus with particular emphasis on fishing-related disturbance from trawling. Bottom trawling is a form of benthic fishing that causes abrasion to the seafloor and is the top contributor of physical disturbance to the benthos.

The model quantifies impacts by integrating disturbance intensity with regional seafloor area, and incorporating ecological recovery dynamics, substrate characteristics, and benthic recolonization potential. It improves the accuracy of previous regional models by including spatially explicit species-area relationships, activity-specific disturbance intensities, and improved recovery data. Preliminary results reveal substantial spatial variability in seabed vulnerability. Smaller or ecologically sensitive marine regions exhibit the highest impacts, reflecting limited area, unique benthic assemblages, or slower recovery rates. In contrast, large oceanic regions show lower values. By providing the first consistent, global-scale CFs for seabed damage, this work fills a critical gap in life cycle assessment (LCA) and offers a scalable framework for evaluating marine biodiversity impacts along value chains. Use of the CFs developed in our study, which will be integrated into the LC-IMPACT methodology, could support more informed decision-making in marine resource management and provide a foundation for regional applications.