High Seas Treaty expected to enter force by 2024, should address climate impacts on migratory marine species: Experts

As nations gear up for a preparatory meeting to discuss the implementation of the High Seas Treaty in June, a new paper published in Nature has proposed three steps essential to protect marine species from climate change.

Countries agreed to a new treaty for the conservation and sustainable use of marine biological diversity in areas beyond national jurisdiction (BBNJ) or high seas treaty in March 2023. It was formally adopted two months later. 

High seas are waters that are beyond national control, comprising around two-thirds of the surface area of the planet’s oceans. Currently, there is no international policy mechanism to conserve biodiversity in these areas.

“Our success in responding to the climate and biodiversity crises also depends on how we can adapt to a constantly changing environment,” Rebecca Hubbard, Director of the High Seas Alliance, said in a statement. 

“As governments gather this month to decide the processes to implement the Treaty, we have an important opportunity to factor in effective responses to marine protection and get ahead of the curve on climate change impacts in over two-thirds of the world’s ocean.”

The paper highlighted that the pace and scale of climate change raise questions about how best to define areas of marine protection. “In particular, how can species that move be conserved as their distributions change because of warming waters?” the researchers wrote.

Marine organisms from whales to fish are on the move as the waters warm up. For example, seabirds that nest in Canada fly to the south of Greenland when the job is done.

“This ocean upheaval, due largely to climate change, can be addressed by the High Seas Treaty, which is why its swift ratification is so important,” Lee Hannah, Senior Scientist of Climate Change Biology at Conservation International’s Moore Center for Science and lead author of the paper said in a statement. 

So far, seven nations have either ratified, accessed, accepted, or approved the treaty. The treaty is expected to enter into force in 2025 after 60 nations ratify it.

The three steps proposed by the paper include collaborating across sectors, simulating how species move, developing strategic conservation plans, and building capacity and mechanisms in the treaty to safeguard marine species.

First, the researchers hope to see bodies responsible for fisheries management and other high-seas organisations sharing existing data and trends. This could then feed into comprehensive regional plans as the treaty comes into force.

The second proposal is to develop systematic plans for managing conservation across the high seas and national waters.

The science and technical body, which will be created as part of the treaty, should advise its secretariat on species movements and changing oceanographic dynamics due to climate change.

Computer modelling can be used to simulate how species move in response to climate change. These results, along with an understanding of key biodiversity areas and existing protections in national waters, can propose priorities for high-seas conservation, the paper read.

“Done well, systematic planning can minimise costs while efficiently conserving moving species and ecosystems and benefiting fisheries and other ocean users,” it added.

The final proposal is to set up governance mechanisms and build capacity. At the preparatory meeting to be held this month, the treaty’s science and technical body should address climate change and foster regional climate conservation plans, the paper noted.

Further, the long-term of the treaty will rest on how countries develop an equitable, shared scientific understanding of how species shift their ranges under climate change.

Currently, models that simulate how species move are based mostly in high-income countries. The High Seas Treaty is designed to promote capacity building and marine technology transfer, supported by a fund to finance these activities.

“We need to be thinking on two timelines at once — how the species in the high seas live now, and how they might live decades from now as climate change worsens,” Hannah explained.

The expert added planning now will help create a solid roadmap ready when the Treaty enters into force.