Deep-pelagic ecosystems should be recognised as distinct social-ecological systems

Deep-pelagic ecosystems, comprising over 90% of Earth's biosphere, are critical for climate regulation, food security, and several global economic activities. However, while interest in deep-sea research and conservation has increased, the focus remains on seafloor-associated ecosystems. Deep-pelagic ecosystems are not only home to thousands of species including fish, crustaceans, squids, salps, and cnidarians. Shrouded in mystery, deep-pelagic ecosystems also hold significant cultural value. Species from these depths, often depicted as monstrous, have inspired narratives from ancient myths to modern entertainment, exemplified many times by the Kraken of Scandinavian folklore and portrayals of anglerfish species. However, deep-pelagic ecosystems are also out of sight, poorly studied, and often understood as remote and disconnected from societal concerns. As global anthropogenic impacts extend into deeper waters, a significant shift in the way society, scientists and policymakers perceive and engage with these ecosystems is required. Social-ecological systems (SES) are integrative research approaches that consider the inseparable and interdependent nature of human societies and ecosystems. The recognition of deep-pelagic ecosystems as SES is crucial for sustainable management, as it highlights the need for sound scientific data and policies that consider both ecological integrity and social well-being. We argue that considering explicitly deep-pelagic ecosystems as SES and incorporating them into conservation and social welfare frameworks is critical to preserving the wide range of benefits they provide. While no formal designation of SES exists, such a process stems from the way SES are approached and prioritized across various disciplinary perspectives. From a scientific standpoint, advancing this concept could involve the establishment of dedicated working groups and targeted funding initiatives by international organisations. These endeavours, grounded in the achievement of UN Sustainable Development Goals, would aim to advance our understanding of deep-pelagic biodiversity, ecosystem functions, societal significance, and effective protection strategies. From an economic perspective, these ecosystems should be embedded in blue economy strategies, acknowledging their roles in fisheries, tourism, and carbon sink, while addressing economic risks from human impacts and exploring biotechnology and sustainable uses. In the absence of a meaningful deep-pelagic authority and policy, science is playing a de facto governance role by shaping the way these ecosystems are understood. We, members of the scientific community, must therefore take the leadership in actively integrating deep-pelagic ecosystems into strategic management and research agendas prioritising interdisciplinary studies that bridge the gap between ecological and social, and economic disciplines. Deep-sea ecosystems must not only be subjects of study and curiosity but also central elements in shaping global policies and practices.