Rapid assessment of cold-water coral habitats in public management maps: a rapid assessment of a fjord with no records of corals

Abstract Marine ecosystems serve as the ultimate repositories for contaminants, with water pollution stemming from human activities such as urbanization, industrialization, and agriculture. In Norway’s coastal regions, competition for ocean space and the protection of marine habitats are increasingly contentious, exacerbated by a lack of data on the distribution of vulnerable species and habitats. Cold-Water Corals (CWC), crucial biodiversity hotspots in deeper waters, face threats from physical damage, industrial effluents, and climate change. Despite their ecological importance, records of CWC in Norway remain sparse, primarily relying on costly state-mandated environmental surveys or specific scientific initiatives. The lack of systematic mapping complicates sustainable, knowledge-based ocean space planning and management. This study demonstrates the effectiveness of Rapid Assessment Surveys (RAS) as a cost-efficient method for detecting CWC and vulnerable marine habitats, particularly in steep and deep fjords. A RAS was conducted in Rovdefjorden, a fjord with high-resolution bathymetric maps and abiotic conditions suggesting potential CWC presence but lacking previous records. Using low-cost equipment, including smaller vessels and commercial-grade remotely operated vehicles (ROVs), CWC was confirmed at multiple sites, revealing several previously undocumented coral habitats. A comparative RAS in Storfjorden, which lacks high-resolution maps, was performed, but encountered operational challenges due to local conditions, yet still successfully confirmed CWC presence. These findings highlight the potential of RAS for rapid biodiversity assessments and underscore the need for broader implementation of such methods in marine management and conservation.