What the High Seas Treaty means for seabirds

Beyond the horizon: what the High Seas Treaty means for seabirds

BirdLife Australia’s Seabird Project Coordinator Dr Yuna Kim explains the significance of the High Seas Biodiversity Treaty – and what it means for global seabird conservation efforts. 

After nearly a century observing the natural world, Sir David Attenborough concluded that the most important place on Earth is not on land, but at sea. For seabird scientists, this is not a revelation but a long-held reality. The open ocean is not an empty blue expanse. It is living habitat – and for albatrosses, petrels, shearwaters and terns, it is where life is lived.

For decades, seabird conservation has focused on what we can see and manage: breeding colonies. We fence beaches, remove predators, restore habitat and monitor nests. These efforts are vital, and many successes have come from them. But satellite tracking over the past twenty years has made something increasingly clear. Most seabirds spend the vast majority of their lives far beyond the colonies we protect, travelling and feeding in international waters – the high seas – where, until recently, there was no meaningful way to protect biodiversity at all.

That gap is now closing. With the High Seas Biodiversity Treaty entering into force in January 2026, and Australia now ratifying the agreement, the rules of ocean governance have fundamentally changed. For the first time, there is a legally binding framework to conserve biodiversity across nearly half the planet.

This matters deeply for seabirds. The high seas are where they feed, migrate and rest – and where they face some of their greatest threats. Chief among these is bycatch: birds killed when they are hooked or entangled in longline and trawl fisheries. Until now, these waters have been managed through a patchwork of sector-based rules focused on resource use rather than ecosystems. Seabirds, which experience the ocean as a connected habitat, have fallen through the cracks.

The new treaty provides tools that have never existed before. It allows countries to establish marine protected areas in international waters. It requires environmental impact assessments for activities that may harm biodiversity. It emphasises capacity building, recognising that conservation depends on monitoring, observer programs and effective mitigation, not just policy statements.

But it is important to be clear-eyed. For seabirds, protection will not come simply from drawing lines on maps. Their habitat is dynamic, shaped by shifting ocean productivity, fronts and currents. Birds and fishing vessels are often drawn to the same places for the same reasons. One of the most urgent challenges is not where fishing occurs, but how it occurs. Proven bycatch mitigation measures already exist, yet uptake and compliance vary widely. Translating treaty ambition into changes on fishing decks will be the real test.

This is where implementation matters. Turning policy into practice will depend on identifying priority high seas areas using tracking data and marine Key Biodiversity Areas, aligning fisheries management with biodiversity objectives, expanding observer coverage and accelerating the adoption of safe, effective mitigation. Success will come from bridging science, governance and real-world fisheries operations.

BirdLife has played a central role in getting us to this point. Globally, BirdLife International and the High Seas Alliance helped ensure biodiversity – and seabirds   – were at the heart of the treaty. BirdLife Australia has contributed science, data and practical fisheries experience, helping link what happens at sea with the policy decisions made far from it.

With the treaty now in force internationally, Australia’s next steps matter. As an island continent with strong marine science capacity, Australia is well-placed to lead – by contributing seabird data to guide protection, strengthening bycatch mitigation through fisheries bodies, and ensuring seabirds are embedded in high seas planning from the outset.

Seabird conservation can no longer stop at the shoreline. The High Seas Treaty gives us a chance, for the first time, to protect the vast blue spaces where seabirds truly live. For species that spend their lives beyond the horizon, this is not abstract diplomacy. It is hope – and an opportunity we cannot afford to waste.