High seas

Accounting for almost two-thirds of the global ocean, the high seas and seabed areas beyond the limits of national jurisdiction (ABNJ) play a critical role in maintaining life on Earth. But, the current framework of governance related to conservation of marine biodiversity in ABNJ is weak and is characterized by large gaps. Gaps include the absence of rules to establish cross-sectorial marine protected area (MPAs) and other effective conservation tools.

About high seas governance

At the 2012 UN Conference on Sustainable Development (Rio +20), States committed themselves "to address, on an urgent basis [...] the issue of the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction, including by taking a decision on the development of an international instrument under the United Nations Convention on the Law of the Sea (UNCLOS)."

(UNCLOS) is an international treaty which was adopted and signed in 1982. 

The Convention has created three new institutions on the international scene :

– the International Tribunal for the Law of the Sea,

– the International Seabed Authority,

– the Commission on the Limits of the Continental Shelf.

Following a two year Preparatory Committee process, the United Nations General Assembly adopted Resolution 72/249 (24 December 2017) to convene an intergovernmental conference (IGC) to develop an international legally binding instrument on marine biodiversity in areas beyond national jurisdiction (BBNJ).



of the Earth’s total habitat by volume is in the high seas

1.5 million km2


of international seabed, roughly the size of Mongolia, has been set aside for mineral exploration

IUCN support to the High Seas Treaty (IGC) negotiations

From the start of the BBNJ process, IUCN has been engaged in the process towards the adoption of an ambitious treaty by enabling an informed decision-making process through the development of knowledge and expertise products, the facilitation of experts workshops and discussions, as well as decisions from its membership. 

The process for the development of an international legally-binding instrument under the United Nations Convention on the Law of Sea on the conservation and sustainable use of marine biological diversity of Areas Beyond National Jurisdiction (BBNJ) has been running for over ten years.  

The negotiations are focused on four main components:  

  • marine genetic resources (MGR); 

  • area-based management tools, including Marine Protected Areas (MPAs); 

  • capacity building and technology transfer; and 

  • and environmental impact assessments.

Policy positions

IUCN Resolution on high seas (2020)

Acting for the conservation and sustainable use of marine biological diversity in the ocean beyond national jurisdiction

Read the resolution read more

IUCN Resolution on deep-sea mining (2020)

Protection of deep-ocean ecosystems and biodiversity through a moratorium on seabed mining

Read the resolution read more

Policy brief on High Seas biodiversity knowledge

Guillermo Ortuño Crespo, Lina Gutierrez-Cala, Ward Appeltans, Patrick N. Halpin & Daniel C. Dunn

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More about our work on BBNJ