Why CMS COP15 Matters for Seamount Conservation

By Sandrine Polti, the Deep Sea Conservation Coalition and Aline Kühl-Stenzel, BirdLife International

From the soaring seabirds that traverse entire ocean basins to the mysterious creatures living thousands of metres below the surface, migratory wildlife depends on healthy ocean ecosystems. This March, governments gathering at the 15th Meeting of the Conference of the Parties (COP15) to the Convention on Migratory Species (CMS) will consider an important new resolution and decision on conserving seamount ecosystems – an opportunity to strengthen protections for migratory species from surface waters to the deep sea.

What is the CMS and why does it matter for the ocean?

The CMS is a global United Nations treaty dedicated to conserving migratory species and the habitats they rely on throughout their life cycles. Because species listed under the treaty cross national borders, and often vast ocean spaces, international cooperation is essential to ensure they are protected wherever they travel.

A new interim update to the State of the World’s Migratory Species 2024 report shows that pressure on these species is increasing. It warns that 49% of CMS-listed migratory species populations are declining, a 5% rise in just two years, while 24% now face extinction, up 2%.

For marine migratory species, the report highlights a ‘pronounced extinction risk’ for regional populations of sharks and rays, with overfishing identified as a major threat across ocean basins. Both targeted fishing and incidental bycatch are key drivers, alongside the degradation of the habitats these species depend on.

Researchers also identified 9,372 Key Biodiversity Areas important for CMS-protected migratory species, yet nearly half of the area covered by these sites still lies outside formally protected or managed zones.

For marine species, these pressures extend far beyond the surface. Many species protected under the CMS, such as whales, sharks and seabirds, depend on ocean features like seamounts that are rich in food and shape their migration routes.

The Resolution and Decision on Conserving Seamount Ecosystems

At CMS COP15, Panama and Monaco have proposed a resolution and decision focused specifically on conserving seamount ecosystems (UNEP/CMS/COP15/Doc.25.3.3). This proposal is important as it helps set priorities for governments, encourages coordinated international action, and strengthens cooperation across ocean governance bodies to better protect migratory species and their ocean habitats.

Seamounts are biodiversity hotspots and ecological stepping stones across the ocean. They act as feeding grounds, breeding areas and navigational landmarks for migratory species including whales, sharks, rays and tuna. The more currents shift and other climatic changes take place across the ocean, the more critical seamounts become as predictable feeding grounds for seabirds and many other ocean travellers. Seamount protection will play a critical role in strengthening the capacity of many migratory species to adapt to climate change.

The Conserving Seamount Ecosystems proposal recognizes that protecting migratory species requires protecting the ecological features they depend on and calls on governments to:

Prioritize protecting seamount ecosystems from destructive fishing practices, within and beyond national jurisdiction, to safeguard migratory species and ecological connectivity.
Promote research to improve knowledge on seamount biodiversity, vulnerability, and ecological roles in supporting migratory species.
Engage Indigenous peoples, scientists, civil society, and industry to raise awareness and strengthen understanding of the importance of seamount ecosystems.
Strengthen cooperation and coherence in seamount conservation through existing international and regional mechanisms, such as the Barcelona Convention, the Convention on Biological Diversity, Regional Fisheries Management Bodies, and the Biodiversity Beyond National Jurisdiction (BBNJ) Agreement.

Connecting across global ocean agreements

The proposed resolution and decision on seamounts does not stand alone. The proposal builds on growing international commitments to protect vulnerable marine ecosystems. For over two decades, the United Nations General Assembly (UNGA) has called on States to prevent significant adverse impacts from bottom fishing on ecosystems such as seamounts. Yet destructive practices like bottom trawling continue, damaging fragile deep-sea corals and sponge habitats that can take centuries, if not millennia, to recover.

The CMS resolution would reinforce these efforts by highlighting the importance of seamounts for migratory species and urging stronger protection across jurisdictions.

It also aligns with broader global frameworks. The Kunming‑Montreal Global Biodiversity Framework commits governments to protect at least 30% of the ocean by 2030, which requires safeguarding ecologically important areas like seamounts. Similarly, the BBNJ Agreement, which entered into force in January 2026, introduces new tools to establish marine protected areas and manage activities on the high seas. Integrating seamount protection into the implementation of the Agreement will be a critical part of delivering its goals.

Momentum is also growing through initiatives such as Motion 032 adopted at the International Union for Conservation of Nature World Conservation Congress in October 2025, which calls for transitioning away from destructive fishing practices on seamounts in international waters by the end of 2026.

Together, these efforts reflect increasing recognition that protecting biodiversity requires coordinated action across international processes, and that the deep ocean must be part of the conversation.

Seamounts and the wider ocean

Seamount conservation shows just how interconnected ocean ecosystems truly are. What happens in the deep sea does not stay there, it ripples through the entire ocean food web, from the microscopic organisms thriving in the nutrient-rich waters around seamounts to the tuna, sharks and seabirds that feed above them.

Decisions made at CMS COP15 reach far beyond the conference room. By recognising the critical role of seamount ecosystems for migratory species, governments can strengthen global efforts to protect the ocean, linking commitments under CMS with those from the UNGA, the biodiversity framework, and emerging high seas governance.

From the surface waters where seabirds glide to the hidden mountains of the deep ocean, protecting seamounts means protecting the vital highways of life that connect our ocean.