High Sea, Distant or Deep Seabeds

Scientific expedition @IRD-Pascale Chabanet


Strengthen decision-making capacity for the conservation of the marine heritage  –  remote or beyond national jurisdiction (BBNJ*) – , within the Nairobi Convention for the ProtectionManagement and Development of Coastal and Marine Environment of the Western Indian Ocean region, and between States

*BBNJ : biodiversity beyond national jurisdiction

  • Making “seamounts” a specific multidisciplinary area of study and recognized as such by the scientific community at the regional level and as an area of public action for the States and the international public organizations.
  • Dissemination of knowledge in marine sciences(oceanography, biology, fisheries, law of the sea and marine environments), including the results acquired during recent oceanographic campaigns (FFEM-SWIO), via a series of training sessions for public decision-makers.
  • Decoding the reforms of the international law of the sea (BBNJ/BADZN)so that States are better prepared in the framework of the ongoing reflections on thegovernance of the oceans in order to set the modalities of a future bilateral or multilateral governance of the spaces, ecosystems and resources of the mountains distant from the coasts in the Western Indian Ocean.

Tools and approaches

Policy briefs on scientific governance and international Law of the Sea

High Level Dialogue and Mutual Training Workshop on Marine heritage knowledge and public decision-making

Special session and Working Group on « Seamounts »

What's new?

June 2023

Explain the relationship between the natural sciences and public decision-making in the governance of marine areas, recalling the provisions of the International Law of the Sea

On March 21, 2023, the Indian Ocean Expedition's restitution day was held in Monaco. It was an opportunity to look back on this campaign rich in scientific discoveries on board the S.A. Aghulas II. 

Leaving Cape Town (South Africa) in early October, the ship made a first stop in Mauritius, before undertaking a circumnavigation in the region passing through Reunion, Aldabra and Mahé in the Seychelles, the Saya de Malha bank, St Brandon, before returning to Mauritius where almost the entire scientific team disembarked.

#Oceanographic Campaign #SayadeMalha

> The Indian Ocean Expedition

 > Restitution day March 2023

Wednesday October 11th 2022

The 12th Western Indian Ocean Marine Science Association (WIOMSA) Symposium in Port Elizabeth,

Mini Symposium : the contribution of marine science in areas beyond national jurisdiction in the Western Indian Ocean to the development of a regional ocean governance strategy

In partnership with the SAPPHIRE program, led by the Nairobi Convention, this mini symposium highlights how advances in oceanographic research in the Western Indian Ocean (WIO) can be used to inform aspects of a regional strategy for ocean governance, particularly as it relates to the conservation and management of biodiversity beyond national jurisdictions (BBNJ).

It provides information on a topic of regional importance, i.e., scientific information on areas beyond national jurisdictions (BBNJ) of the Western Indian Ocean (WIO) littoral states, which is currently relatively limited and poorly distributed and shared. The contribution of this information to a regional strategy to improve ocean governance in the WIO will be primarily to ensure that the importance of maintaining marine biodiversity in a healthy state to provide the basis for a sustainable blue economy is emphasized and integrated.

   > read the mini symposium description

The Nairobi Convention (NC) has asked its 10 Parties and other key stakeholders to nominate representatives to contribute to the development of a Regional Ocean Governance Strategy (ROGS) for the Western Indian Ocean. These individuals will form a Task Force (TF) which will have to finalise its proposals by November 2023, the date of the next NC COP 11.

In April 2022, France appointed Florence GALLETTI (Marine Science & Law of the Sea) and Francis MARSAC (Oceanography), members of DiDEM, and Benoit RODRIGUES (International Affairs and Partnerships, IRD)

Learn more about the Task Force

From April 19 to May 24, 2022, the RESILIENCE cruise took place in the Mozambique Channel and along the east coast of South Africa. This multidisciplinary campaign focused on the influence of small-scale physical processes on biological production at the edge of oceanic eddies present in the area. It brought together scientists from many countries including South Africa, Mozambique and Mauritius.

Jean-François Ternon, coordinator of the DiDEM High Seas component, participated as cruise leader.

Know more about the cruise

Context, team & partners

The High Sea component's context

The Indian Ocean is home to many seamounts ( approximately 2900), rich, fragile, vulnerable ecosystems, with ecological functions threatened by anthropogenic pressures (Marsac, Galletti, Ternon et al, 201911): Among them, fishing - since seamounts attract many fish species, including a large proportion of species that are not very resistant to exploitation, and by and large of very high commercial value and mining - since seamounts contain nodules and polymetallic sulfides of nickel, cobalt, copper, platinum and other rarer metals.

To ensure the conservation of these habitats and their biodiversity, it is essential that protection measures are put in place through a recognized legal and institutional framework, and on the basis of the knowledge acquired by various oceanographic campaigns carried out during the last decade (some of which were carried out by the IRD and the MNHN).


2 coordinators

Florence Galletti (IRD), jurist, law of the sea

Jean-Francois Ternon (IRD), oceanographer physician

Appui Scientifique

Sophie Cuenot (IRD), jurist, research engineer

Francis Marsac (IRD), marine ecologist

Julien Barde (IRD), information technology

Jurist (to be recruited, based in WIO)