By Lina Dahl
With the ongoing race to explore, exploit and expand into the deep sea, one question becomes increasingly crucial: how do we govern a place we cannot see, hear, or feel? Far below the surface waters, life glows, thrives, and prospers. Unseen, unheard, and unfelt by humankind, the vast darkness lies far beyond our reach, yet human ambition reaches evermore towards it. The deep sea is characterised by its remoteness, with the quote “out of sight, out of mind” one can begin to understand the challenges of deep-sea governance. The deep sea, which includes all waters below 200 meters is of great importance to our planet’s health and human well-being. Deep down in the darkness lie spectacular creatures (some shaped by deep sea gigantism), long-time buried carbon, ancient sediments and much more.[i] These creatures and ecosystems are a mystery to us, but undoubtedly essential for all life on earth.[ii] Despite this importance, the deep sea is facing severe knowledge gaps, making governance even harder.[iii] In recent years the pressure from economic activities has moved deeper into the ocean. Fishing fleets are beginning to trawl at greater depths, mining companies are mapping the minerals on the seabed, and submarine cables and other infrastructures are placed in fragile ecosystems we know very little about.[iv]
Although much of the deep sea feels distant to our societies, it is through ecosystem services that the deep sea ultimately connects to our everyday life on land. Ecosystem services are the direct and indirect benefits humankind gains from the ecosystem, such as climate regulation driven by ocean circulation between the surface and the deep sea. The deep sea provides humans with a wide range of ecosystem services. Although there is a long list of ecosystem services, it can be interesting to look at the most fundamental ones for the deep sea in connection to human well-being. Firstly, there is the regulating services, which includes carbon sequestration and storage. It is calculated that twice the amount of carbon of terrestrial soil can be found in ocean sediments, and 79% of these at the abyssal depths. Apart from carbon sequestration, nutrient upwelling is another important regulating service from the deep sea, cycling nutrients such as phosphorus, nitrogen and silica. These nutrients are the building blocks of productivity in the ocean.[v]
Secondly, biodiversity & genetic resources serve as important supporting and provisioning services for industrial and pharmaceutical applications. Biodiversity is the fundamental pillar for all life on earth, and the deep sea has a vast amount of biodiversity. Next to this, the potential for marine genetic resources that can help prevent and treat diseases are huge and largely unexplored. In the deep sea, over 91% of the species remain undiscovered.[vi] Due to the incredibly unique environments in the deep sea, organisms have evolved distinctive biochemical compounds to help them adapt to high pressure and low light, alongside physiological and morphological adaptations. These compounds offer the potential of contributing to breakthroughs in many areas, medicine being the biggest one. Blue bioprospecting has already led to the discovery of compounds in deep-sea sponges being used in technologies and cancer research. Another provisioning service is deep-sea fishing, with high biodiversity around seamounts, banks and cold-water reefs, many species have the potential to build up large stocks in these areas.[vii]
Lastly, the cultural services. Not only does the deep sea hold valuable spiritual meaning for many indigenous communities around the world, but it also provides inspiration for art and culture. The narrative of the deep sea being a vast empty space is nothing other than wrong, it holds intense cultural and spiritual significance for many communities.[viii] An example of the spiritual meaning of the deep sea for certain communities is the communities living close to the Solwara 1 project in Papua New Guinea. The Solwara 1 project is the world’s first commercial mining lease. Research has shown that the communities found the impacts of deep-sea mining on bodies of spirits was of greatest concern.[ix]
Oddly enough, this vital environment remains one of the least governed places on the planet, constrained by a lack of scientific knowledge, uncertain jurisdiction, and soft law. Legally, the deep sea does not have an agreed upon definition, highlighting how underrepresented this space is.[x] The challenge of balancing environmental protection and economic activities becomes prevalent here. International, regional, and national policies must work towards environmental protection to sustain these vital ecosystem services, alongside managing economic activities for growth.[xi] Especially important is noting that most of the deep sea lies beyond national jurisdiction, highlighting the critical factor of international cooperation under frameworks such as the United Nations Convention on the Law of the Sea (UNCLOS)[xii] and The Agreement on Marine Biological Diversity of Areas beyond National Jurisdiction (BBNJ treaty). The challenge facing the governance of the deep sea is urgent, and deeply human, as humankind profoundly depends on what happens far beneath the surface.[xiii]
However, the challenge is not just part of a physical inaccessibility but from historical practices. The current maritime domain was developed for surface navigation, fishing practices and resolving territorial boundaries and has rather evolved to include bioprospecting, valuing carbon sequestration, and including ecosystems around hydrothermal vents that had never been seen before.[xiv] Coastal zones and the upper layer of the water column have the advantage of centuries of exploration, development of maritime practices and laws, while the deep sea lacks this history and is therefore left in a state of vulnerability due to being introduced into a framework that isn’t necessarily developed with the deep sea in mind. Leaving it at risk of heavy exploitation from economic interests. The modern policies and frameworks applied to the deep sea are therefore inadequate to answer the emerging questions in relation to the deep sea, but policies are also evolving.[xv]
In the international legal frameworks, UNCLOS is seen as the foundation for ocean governance. However, when analysing the provisions in relation to the seabed of the deep sea (The Area), through Part XI of UNCLOS[xvi], there are clear discrepancies around the environmental threshold, equitable distribution of resources, and enforcement. UNCLOS established the International Seabed Authority (ISA) and tasked it with regulating mineral-related activities in the Area.[xvii] Its task is to manage these resources to the benefit of all humankind. Its dual mandate is condemned as potentially placing extraction over precaution since it considers commercial mining proposals without full baseline information about the environment. The BBNJ treaty, also known as the “Paris Agreement of the ocean,” aims to overcome these shortcomings through environmental impact assessments, marine protected areas, and sharing of benefits.[xviii] The treaty will fill critical gaps of UNCLOS when it comes into force 17 January 2026. Ratification, however, does not guarantee implementation. Political will, capacity development, and scientific cooperation will determine whether the treaty can really safeguard the deep sea in a meaningful way.[xix]
The temporal mismatch between policy cycles and ecological timescales is another fundamental governance gap. Deep-sea processes frequently run for centuries, but regulations are reviewed every few years. No existing monitoring framework considers the fact that a single mining plume could affect seafloor recovery for millennia.[xx] Additionally, there is a lack of accountability. Responsibilities are diminished in domains outside of national jurisdiction. For irreparable harm to deep-sea ecosystems, there is currently no legally binding liability regime in place.[xxi] Leaving room for harmful economic activities to continue without sufficient oversight or regulation, thereby weakening the protection of vulnerable marine areas.
Economic activities in the deep sea come with both challenges and opportunities. The activities include deep-sea bed mining, fishing and bottom trawling, lying cables and other infrastructures, and bioprospecting for genetic resources. Deep-sea bed mining is the economic activity most present in current narratives about the deep sea. The argument from advocates of deep-sea mining includes the fact that transition minerals found on the abyssal plains are essential for the transitioning to green technology.[xxii] However, the opposing argument is that deep seabed mining is not necessary and possess unnecessary environmental and social risks.[xxiii] This narrative comes hand in hand with a moral paradox that needs to be addressed: the justification of potentially destroying one ecosystem in favour of protecting another. Historically, developing extractive models under time pressure have produced significant harm on the environment. The question that remains is whether the deep sea can be protected through legislation. Therefore, stress needs to be put upon the precautionary approach and adaptive governance. The precautionary principle calls for seeking more scientific knowledge in an area where it is currently lacking, before conducting potential harmful activities.[xxiv] An updated moratorium is being suggested for deep-sea bed mining, highlighting the urgency of protecting the environment and avoiding damaging ecosystems we do not currently understand.[xxv]
Countries with vast maritime spaces play key roles in advancing deep-sea governance and share a responsibility in ocean stewardship. One concrete example of this is Portugal. With the 3rd largest Exclusive Economic Zone (EEZ) in the EU[xxvi], and approximately 98% of the ocean within national jurisdiction being deep sea, Portugal plays an important role in leading the deep-sea management agenda. Portugal already promotes greater scientific integration in decision-making through its Blue Economy initiatives and involvement in high-level ocean dialogues.[xxvii] However, until enough information is gathered, this leadership must now also support moratoria on high-risk activities. Portugal, like all maritime countries, faces the challenge of moving beyond mere rhetoric. Deep-sea stewardship calls for partnerships with states that lack infrastructure to exploit and explore but have equal stakes in the global commons, as well as investments in deep-ocean research vessels, and data transparency. Not only can Portugal play an important role in deep-sea governance, but it can also foster international collaboration on the topic. There is an ever-increasing need for understanding the importance of the science-policy interface; policy cannot come before science. Establishing a moratorium for deep-sea ecosystems will allow for science to conduct enough research to guide policy in the right direction.[xxviii]
To govern what we cannot see, hear or feel, we must first choose to protect humanity. A pause in the name of the precautionary principle is not a wish to stay inactive, but a conscious decision to acquire deeper knowledge. Humanity embracing stewardship and curiosity over exploitation will steer future deep-sea governance. Ultimately, choosing cooperation over competition. This can be done through multiple different means, two of the most prevalent being halting deep sea mining through an updated moratorium and banning deep-sea bottom trawling. Portugal, as a maritime country, can lead in shaping this type of good governance, focusing on guarding rather than conquering the ocean. As the BBNJ treaty enters into force, the world faces a new challenge in ensuring that the laws will follow science and science will follow the ocean. Significant change will depend on countries willingness to stress the need for long-term ocean health over short-term political and economic interests. Unseen, unheard, unfelt, the deep sea remains silent, yet governance can give it a voice.
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License https://creativecommons.org/licenses/by-nc/4.0/
[i] National Oceanography Centre. “Monsters of the Deep.” Accessed October 14, 2025. https://noc.ac.uk/under-the-surface/monsters-deep.
[ii] Le, Jennifer T, and Kirk N Sato. Ecosystem Services of the Deep Ocean. Ocean & Climate Platform (ocean-climate.org), n.d. https://ocean-climate.org/wp-content/uploads/2017/03/ecosystem-services-deep-ocean_ScientificNotes_Oct2016_BD_ppp-9.pdf
[iii] Folkersen, Maja Vinde, Christopher M. Fleming, and Syezlin Hasan. “Depths of Uncertainty for Deep-Sea Policy and Legislation.” Global Environmental Change 54 (January 2019): 1–5. https://doi.org/10.1016/j.gloenvcha.2018.11.002.
[iv] Yu, Ting, Rui Liu, and Ying Jin. “Toward Ecosystem-Based Deep-Sea Governance: A Review of Global Approaches and China’s Participation.” Marine Development 3, no. 1 (2025): 1. https://doi.org/10.1007/s44312-024-00045-y.
[v] Armstrong, Claire W., Naomi S. Foley, Rob Tinch, and Sybille Van Den Hove. “Services from the Deep: Steps towards Valuation of Deep Sea Goods and Services.” Ecosystem Services 2 (December 2012): 2–13. https://doi.org/10.1016/j.ecoser.2012.07.001..
[vi] NOAA, How Many Species Live in the Ocean?, National Ocean Service, last modified June 16, 2024, https://oceanservice.noaa.gov/facts/ocean-species.html
[vii] Armstrong, Claire W., Naomi S. Foley, Rob Tinch, and Sybille Van Den Hove. “Services from the Deep: Steps towards Valuation of Deep Sea Goods and Services.” Ecosystem Services 2 (December 2012): 2–13. https://doi.org/10.1016/j.ecoser.2012.07.001..
[viii] Armstrong, Claire W., Naomi S. Foley, Rob Tinch, and Sybille Van Den Hove. “Services from the Deep: Steps towards Valuation of Deep Sea Goods and Services.” Ecosystem Services 2 (December 2012): 2–13. https://doi.org/10.1016/j.ecoser.2012.07.001..
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[xi] Yu, Ting, Rui Liu, and Ying Jin. “Toward Ecosystem-Based Deep-Sea Governance: A Review of Global Approaches and China’s Participation.” Marine Development 3, no. 1 (2025): 1. https://doi.org/10.1007/s44312-024-00045-y.
[xii] Sander, Sylvia, Christian Tamburini, Sabine Gollner, et al. Deep Sea Research and Management Needs. Zenodo, 2025. https://doi.org/10.5281/ZENODO.14928917.
[xiii] Sander, Sylvia, Christian Tamburini, Sabine Gollner, et al. Deep Sea Research and Management Needs. Zenodo, 2025. https://doi.org/10.5281/ZENODO.14928917.
[xiv] OECD. The Ocean Economy in 2030. OECD, 2016. https://doi.org/10.1787/9789264251724-en.
[xv] Yu, Ting, Rui Liu, and Ying Jin. “Toward Ecosystem-Based Deep-Sea Governance: A Review of Global Approaches and China’s Participation.” Marine Development 3, no. 1 (2025): 1. https://doi.org/10.1007/s44312-024-00045-y.
[xvi] United Nations Convention on the Law of the Sea, 10 December 1982, Part XI, Art. 157, https://www.refworld.org/legal/agreements/unga/1982/en/40182.
[xvii] United Nations Convention on the Law of the Sea, 10 December 1982, Part XI, Art. 157, https://www.refworld.org/legal/agreements/unga/1982/en/40182.
[xviii] Agreement under the United Nations Convention on the Law of the Sea on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction, adopted 19 June 2023, not yet in force, UN Doc A/CONF. 232/2023/4 (19 June 2023).
[xix] Hilmi, Nathalie, Wassim Dbouk, Matías Crisóstomo, et al. “Governing the Deep: Economic, Ecological, and Legal Perspectives on Deep-Sea Mining in Areas beyond National Jurisdiction.” Marine Policy 183 (January 2026): 106887. https://doi.org/10.1016/j.marpol.2025.106887.
[xx] Folkersen, Maja Vinde, Christopher M. Fleming, and Syezlin Hasan. “Depths of Uncertainty for Deep-Sea Policy and Legislation.” Global Environmental Change 54 (January 2019): 1–5. https://doi.org/10.1016/j.gloenvcha.2018.11.002.
[xxi] Sander, Sylvia, Christian Tamburini, Sabine Gollner, et al. Deep Sea Research and Management Needs. Zenodo, 2025. https://doi.org/10.5281/ZENODO.14928917.
[xxii] Hilmi, Nathalie, Wassim Dbouk, Matías Crisóstomo, et al. “Governing the Deep: Economic, Ecological, and Legal Perspectives on Deep-Sea Mining in Areas beyond National Jurisdiction.” Marine Policy 183 (January 2026): 106887. https://doi.org/10.1016/j.marpol.2025.106887.
[xxiii] Environmental Justice Foundation, Critical Minerals and the Green Transition: Do We Need to Mine the Deep Seas?(London: Environmental Justice Foundation, 2022), 1–2, https://ejfoundation.org/resources/downloads/EJF_critical-minerals-and-the-green-transition.pdf
[xxiv] OECD, Understanding and Applying the Precautionary Principle in the Energy Transition (Paris: OECD Publishing, 2023), [page number], https://www.oecd.org/en/publications/understanding-and-applying-the-precautionary-principle-in-the-energy-transition_5b14362c-en.html
[xxv] Sander, Sylvia, Christian Tamburini, Sabine Gollner, et al. Deep Sea Research and Management Needs. Zenodo, 2025. https://doi.org/10.5281/ZENODO.14928917.
[xxvi] European Commission, “Portugal — Maritime Spatial Planning,” Maritime Spatial Planning in Countries (European Commission), accessed October 15, 2025, https://maritime-spatial-planning.ec.europa.eu/countries/portugal.
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