The agreement reached by UN delegates on a Draft High Seas Treaty on March 4, 2023, has been widely celebrated as a historic achievement in protecting the ocean. This post considers it in light of the objective to conserve biological diversity, which is one of the treaty’s main goals and underpins the entire UN biodiversity framework. The post starts by outlining the legal regime applicable to the high seas and identifying one of the significant threats marine life and ecosystems face. It then assesses whether the instrument designated by the treaty to ensure the conservation of marine biological diversity – i.e., marine protected areas – appears adequate for this purpose.

The UN Biodiversity architecture

Since adopting the Rio Convention on Biological Diversity in 1992, its Conference of Parties has decennially adopted a new ‘strategic plan’ to measure progress on biodiversity protection and set new global targets. With each successive instrument, the language has grown more urgent regarding the accelerating rate of biodiversity loss and more assertive about the need for concrete and sweeping measures to prevent irreparable damage to the natural world.

Hence the last of these agreements adopted on December 19, 2022  – the Kunming-Montreal Biodiversity Framework – declares that ‘biodiversity is deteriorating worldwide at rates unprecedented in human history.’[1] It underlines that this ecological decline is threatening around a million species of plants and animals with extinction as the ongoing destruction of nature brings about biological evolutionary changes.^[2] The Kunming-Montreal agreement importantly acknowledges that the collapse of biological diversity is predominantly caused by humans, resulting largely from the overexploitation of animals, plants, and living organisms, primarily via harvesting, logging, hunting, and fishing.

In its last global assessment report of 2019, the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) stressed that nothing but transformative change – described as fundamental, structural change – can halt human-driven degradation of the natural world.[4] However, under current projections, human pressure on nature will continue or worsen in many future scenarios.

In the Kunming-Montreal agreement, the international community responded to the IPBES report by committing ‘to bring about a transformation in our societies’ relationship with biodiversity’ and halt biodiversity loss by 2030.[6] For this purpose, world nations have agreed on 23 targets building on the 20 Aichi targets agreed in 2011.[7] The most well-known of them, the ‘30 by 30’ pledge, refers to a commitment to protect at least 30% of the world’s terrestrial and marine areas by 2030.[8] This expands the initial goal to conserve 17% of terrestrial and 10% of marine areas by 2020, one of the only four Aichi targets towards which good progress was achieved in the last decade.

One significant step towards the realization of the 30 by 30 target in marine areas was taken on March 4 when following intense and protracted negotiations; a UN Intergovernmental Conference adopted a Draft agreement on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction, colloquially known as ‘the High Seas Treaty’ (the treaty).

The general objective of the treaty, as stated in article 2, is ‘to ensure the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction.’[11] For this purpose, it encourages states to ‘establish a comprehensive system of area-based management tools, with ecologically representative and well-connected networks of marine protected areas’ on the high seas.[12] It also requires conducting environmental impact assessments for certain activities undertaken in the ocean. It establishes the principle of fair and equitable sharing of benefits obtained from marine genetic resources, as discussed here.[13]

A tragedy of the commons

The ocean lying beyond the 200 nautical mile limit of national jurisdictions in the sea, representing about 60% of the global ocean, is the largest unappropriated area of the world. While coastal states have the exclusive right to exploit marine resources in their sovereign seas, known as their ‘exclusive economic zones,’ the high seas are open to all states.[14] The doctrine of the freedom of the high seas enshrined in the UN Convention on the Law of the Sea (UNCLOS) has given rise to a phenomenon called the ‘tragedy of the commons, referring to situations where shared resources are depleted as private actors pursue their self-interest at the expense of the common good.[15]

The freedom of the nationals of all states to fish on the high seas is probably the most problematic when it comes to protecting marine biodiversity.[16] Under the UNCLOS, this freedom is subject to the duty of states to ensure the conservation of the living resources of the high seas, including an obligation to cooperate with other states for this purpose.[17] This duty has led to the creation of regional fisheries management organizations tasked to regulate fishing and set quotas for fish stocks to ensure their conservation and sustainable use.[18] According to Article 119 of the UNCLOS, fishing quotas and other conservation measures on the high seas should be determined based on the following criteria:

the harvested species should be maintained or restored ‘at levels which can produce the maximum sustainable yield.’

species associated with or dependent on the target stocks should be kept or restored ‘above levels at which their reproduction may become seriously threatened.