Pedro Sepúlveda

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.

The mesophotic zone represents one of our planet’s largest and least explored biomes. An increasing number of studies evidence the importance of macrofouling species in marine ecosystems, but information on these communities and the factors influencing their structures at mesophotic depths remain poor. This lack of understanding limits our ability to predict anthropogenic impacts or conduct restoration operations in the mesophotic and the lower boundary of the euphotic zones. In this study, we performed a 24-month experiment in a natural environment to investigate three factors influencing the macrobenthic community structure of the mesophotic and the euphotic lower boundary: depth, substrate orientation and substrate material. Using a manned submersible, several recruitment panels of two different materials were deployed at 100, 200 and 400 meters in vertical and horizontal positions. All three factors contributed to structuring the macrofouling communities, but depth and substrate orientation displayed the strongest effects. This study not only advances our understanding of lower boundary euphotic and mesophotic macrofouling communities but also establishes a foundation for future research and restoration efforts of mesophotic environments in the Madeira archipelago, where mesophotic habitats are amongst the least studied marine habitats in the Northeast Atlantic.

The global economy is increasingly focusing on the Oceans to meet its needs, for which maritime spatial planning is being fostered to promote this is done sustainably. Thus, assessing the current state and future development trends of the maritime sectors is key to evaluating the performance of the planning process. This is the aim of this study, in which the main maritime sectors related to the blue economy present in the archipelagos of the European Macaronesia Sea Basin, i.e. the Azores and Madeira (Portugal), and the Canary Islands (Spain), were identified and studied. The following maritime sectors were analysed: fisheries, marine aquaculture, marine biotechnology, coastal and maritime tourism, maritime transport, ship repair and maintenance, extraction of aggregates, deep-sea mining, offshore oil and gas, renewable ocean energies, and desalination. As part of the PLASMAR project, partners undertook in 2017–19 a literature review gathering scientific papers, official statistics and reports, which were complemented by interviews with experts from the economic sectors and public administration departments. Results show that while some maritime sectors are well established, others are emerging sectors with varying long-term growth potential. Besides, development patterns vary across the archipelagos. This study represents the first effort in the Macaronesia Sea Basin to set the basis of the current and future development conditions of the blue economy in applicability to maritime spatial planning processes at a regional level. The future post-pandemic context will provide a unique opportunity to promote the blue economy sectors and activities through the support provided by the EU Green Deal and Recovery and Resilience Plans, as well as with the actions envisioned under the United Nations Decade of Ocean Science for Sustainable Development (2021–2030). The European Macaronesia example –given its wide maritime territory, commitment, and capacities in terms of expertise and networking– presents a great potential to act as a good practice to extrapolate the new approach for a sustainable blue economy to other similar geographical settings such as island regions/states.