The Current State of Knowledge and the Urgent Need for More Research

The deep sea is one of the most under-explored regions on our planet. Despite its immense importance for ecosystems and biodiversity, human activities such as oil extraction, fishing, and potential seabed mining threaten deep-sea ecosystems, while climate change is already having a negative impact. A group of internationally renowned marine scientists has published a Future Science Brief on deep-sea research, which provides a comprehensive analysis of the current state of knowledge and offers recommendations for how both the exploration and management of the deep sea can be made more sustainable. The report highlights the urgent need for targeted research to close the knowledge gaps and ensure long-term preservation of the deep sea.

The Definition of the Deep Sea and the Importance of Its Ecosystems

The deep sea is generally defined as the water column and seabed below 200 meters. This definition was chosen by the members of the European Marine Board’s Deep Sea and Ocean Health Working Group. This region accounts for about 90 percent of the ocean’s volume and plays a crucial role in the global carbon cycle and oxygen production. However, the deep sea is still relatively untouched, and its importance for ecosystems and biodiversity is immense. Complex ecosystems can be found along continental slopes, on abyssal plains, or around hydrothermal vents – so-called black smokers – many of which remain poorly understood.

The Threats to the Deep Sea from Human Activities

Human activities are already affecting the deep sea in many ways. Irreversible changes on human timescales – such as warming, acidification, and oxygen loss – are threatening these sensitive habitats. At the same time, overexploitation of fish stocks and non-renewable resources such as oil, gas, and minerals is jeopardising biodiversity and ecosystem functions.

The Importance of Targeted Research

The scientists agree that 2025 is a decisive year to take action for ocean health. It is crucial to take effective measures against climate change now in order to achieve net-zero emissions by 2050. This research is essential for supporting science-based decision-making for deep-sea governance, the scientists argue.

The Role of the EU in Protecting the Deep Sea

The working group emphasizes that Europe should take a leading role in the international protection and sustainable governance of the deep sea, particularly through existing international agreements. The researchers also call for secured funding of transdisciplinary research and long-term monitoring. They argue that better understanding the state of the ocean is essential for protecting and using the deep sea sustainably.

The Challenges of Researching the Deep Sea

Physical oceanography faces considerable gaps in the modelling of deep currents that are crucial for the transport of nutrients and pollutants. In marine geochemistry, little is known about how biogeochemical cycles in the deep sea are affected by human activities such as mining. Technical challenges also remain: many modern sensors and monitoring systems are not yet adequately developed for extreme depths, making it difficult to gather essential data.

The Urgent Need for More Research

The report highlights the urgent need for more research to close the knowledge gaps and ensure long-term preservation of the deep sea. Without a thorough understanding of ecosystem processes and biodiversity, informed decisions on the sustainable use and protection of the deep sea are not possible.

• Effective governance of human activities in the deep sea is essential for protecting the ecosystem.
• Establishing an international scientific committee for deep-sea sustainability and protection is crucial for coordinating efforts and ensuring a unified approach.
• Contribution to the development and implementation of deep-sea Environmental Impact Assessments is vital for minimizing the risks associated with human activities.
• Supporting transdisciplinary research programs is necessary for better understanding the role of the deep sea in Ocean (and human) health.
• Long-term monitoring in the deep sea is essential for tracking changes and developing effective management strategies.
• Launching large-scale and long-term multidisciplinary natural sciences projects is necessary for increasing knowledge of global deep-sea processes.
• Supporting research efforts in critical fields is vital for addressing the complex challenges facing the deep sea.
• Enhancing educational, training, and research opportunities for scientists is necessary for ensuring the next generation of researchers is equipped to tackle the challenges of the deep sea.
• Fostering the transfer of marine technology and developing training programs is essential for promoting the adoption of sustainable practices.
• Continuing to promote the Findability, Accessibility, Interoperability, and Reusability (FAIR) Data Principles is crucial for ensuring the long-term availability and usability of research data.

The Future of the Deep Sea

The deep sea is an indispensable part of our planet’s ecosystem. It is a vital component of the global carbon cycle and oxygen production, and it plays a crucial role in maintaining the health of our oceans. However, the deep sea is facing numerous threats, including climate change, overfishing, and pollution. It is essential that we take action to protect the deep sea and ensure its long-term preservation.

Conclusion

The deep sea is a critical component of our planet’s ecosystem, and its preservation is essential for the health of our oceans. With the publication of this report, we hope to raise awareness about the importance of the deep sea and the need for more research to close the knowledge gaps and ensure long-term preservation of the deep sea.

References

Sander, S. G., Tamburini, C., Gollner, S., Guilloux, B., Pape, E., Hoving, H. J., Leroux, R., Rovere, M., Semedo, M., Danovaro, R., Narayanaswamy, B. E. (2025) Deep Sea Research and Management Needs. Muñiz Piniella, A., Kellett, P., Alexander, B., Rodriguez Perez, A., Bayo Ruiz, F., Teodosio, M. C., Heymans, J. J. [Eds.] Future Science Brief N°. 12 of the European Marine Board, Ostend, Belgium.

About the European Marine Board

The European Marine Board (EMB) is a partnership of 38 organisations from 19 European countries that are active in marine research. Its mission is to strengthen cooperation in European marine science and develop joint research strategies. The EMB acts as a bridge between science and policy, supports knowledge exchange, and provides recommendations to national authorities and the European Commission to advance marine research in Europe. Its members include leading oceanographic institutes, research funders, and universities with a marine focus.

Background

The EMB was founded in 1995 and has since played a crucial role in advancing marine research in Europe. The EMB has published numerous reports and publications on various aspects of marine research, including the deep sea. The Future Science Brief N°. 12 of the European Marine Board is the latest publication in this series, and it highlights the urgent need for more research to close the knowledge gaps and ensure long-term preservation of the deep sea.

“The ocean is an interconnected system stretching from the coast to the deepest depths. Of course, the deep sea cannot be considered in isolation from the photic zone or the seafloor,” – Sylvia Sander

“Climate change is one of the most alarming threats to our life-support systems and to life on Earth itself. Combined with biodiversity loss, it could soon lead to severe and irreversible disruptions to the entire ocean – including the deep sea and ice-covered parts of the planet.”
“The ocean stores vast amounts of CO2 and heat, helping to mitigate climate change.