Work

High-resolution predictive mapping reveals novel benthic habitats in the southern Baltic Sea

Year: 2025

Type: article

Abstract: Marine benthic habitats are essential for biodiversity and ecosystem functioning, yet their complexity and inaccessibility challenge effective mapping and management. This study presents the first high-resolution predictive benthic habitat maps at the EUNIS Level 5 for the Polish Exclusive Economic Zone (EEZ) in the southern Baltic Sea, covering over 7000 km 2 of direct high-resolution measurements. Using advanced hydroacoustic technologies—multibeam echosounders and side-scan sonars—combined with 1425 sediment grab samples and underwater video ground-truthing, we applied a Random Forest classifier trained on bathymetric derivatives via Object-Based Image Analysis (OBIA). The model achieved high accuracy: 96.94 % overall and a kappa coefficient of 0.94 for substrate classification, and 97.88 % overall with a kappa of 0.97 for dominant species. We identified 47 distinct benthic habitats, including 24 novel EUNIS Level 5 unique to the southern Baltic, requiring the proposal of three new EUNIS Level 4 categories to maintain taxonomic hierarchy. These findings enhance understanding of Baltic Sea biodiversity and provide a scalable framework for benthic habitat mapping, supporting ecosystem-based management under increasing anthropogenic pressures. • First high-resolution EUNIS Level 5 benthic habitat maps for 7000 km 2 Polish EEZ • Integrated hydroacoustics and machine learning achieved >96 % habitat classification accuracy • Identified 24 novel Baltic benthic habitats, expanding EUNIS framework for conservation

Source: The Science of The Total Environment

DOI: 10.1016/j.scitotenv.2025.180997