Transforming Seafloor Litter Monitoring: Innovative Technologies for Greater Reach

• DOI: 10.5194/oos2025-1387
• Publication Date: 2025-03-26T02:42:35Z
• Authors: João Gama Monteiro; Pedro Sepulveda; Marisa Gouveia; Jose Luis Gómez; Hilda de Pablo; Garbiñe Ayensa; Vicente Pérez; Camille Lacroix; Claire Allanos; Tomasz Dabrowski; Pablo Otero; Sandra Moutinho; Olivia Gerigny; Olivia Jones; Joao Canning-Clode; Marisa Fernandez

The increasing prevalence of plastic pollution in marine environments has necessitated a paradigm shift in seafloor monitoring methodologies. Efforts to compile information and current state of the art for seafloor litter monitoring has highlighted the urgent need for innovative solutions to enhance and upscale current capabilities for assessing plastic pollution on the ocean floor. Traditional methods, particularly trawling, have been widely employed in opportunistic fashion to monitor seafloor litter; however, they pose significant challenges and drawbacks. Trawling not only disrupts benthic ecosystems but also leads to the destruction of habitats and non-target species, thereby exacerbating the very issues it aims to address. This is one of the main arguments supporting the cessation of trawling as a monitoring method and advocateing for the establishment of dedicated surveys and monitoring programs that leverage advanced technological solutions. Mapping and surveying the ocean's seafloor presents a multitude of challenges, including the vastness of marine environments, the complexity of underwater topography, and the limitations of existing technologies. Current estimates suggest that over 80% of the ocean floor remains unmapped, largely due to the high costs and logistical difficulties associated with traditional survey methods. This knowledge gap hampers effective management and mitigation strategies for plastic pollution, which poses a significant threat to marine biodiversity and ecosystem health. To address these challenges, we review and explore the evolution of relavant technolgical solutions for seafloor litter detection and mapping. Our review emphasizes current technological and methodological advances that will greatly facilitate the future of seafloor litter monitoring, including video surveys conducted by scuba divers, remotely operated vehicles (ROVs), autonomous underwater vehicles (AUVs), and tow cameras. These platforms offer the potential for high-resolution data collection while minimizing ecological disturbance. Additionally, sonar-based technologies, including multibeam, side-scan sonar, and imaging sonar, provide comprehensive mapping capabilities that can significantly enhance our capability to map seafloor litter distribution in relevant spatial scales. Paired with recent and upcoming advances in AI and deep-learning, imagery based surveys will be greatly streamlined and become increasingly less demanding. The future of seafloor litter monitoring hinges on the adoption of cutting-edge technologies that can provide reliable, high-resolution data while preserving benthic ecosystems. Currently available technological solutions are often prohibitively costly to deploy regularly and at meaningful scales, however, innovations in marine robotics, sensor technology, data processing, and automation can lead to more cost-effective solutions, making large-scale monitoring programs feasible. This is particularly important given the growing urgency to address plastic pollution, which requires sustained and systematic monitoring efforts to diagnose its impacts on benthic habitats.By moving away from destructive methods like trawling and embracing dedicated monitoring programs that utilize advanced underwater platforms, we can enhance our understanding of plastic pollution's impacts on marine environments. Our findings and outlined position underscores the critical need for interdisciplinary collaboration among scientists, technologists, and policymakers to develop and implement cost effective innovative solutions that will shape the future of seafloor monitoring and contribute to the health of our oceans.