AbstractIn the past thirty years since the signing of the UN Convention on the Law of the Sea (LOSC), the ocean has changed more than in all of human history before. It is now facing a multitude of interconnected threats that require comprehensive, precautionary and integrated management. This review of the environmental provisions in Part XII of the LOSC with respect to the high seas and the seabed area beyond national jurisdiction (ABNJ) reveals significant strengths as well as substantial weaknesses and gaps. Governments are now grappling with how to address problems related to the conservation and sustainable use of marine biodiversity in ABNJ. This commentary concludes that Part XII will need strengthening, including through an implementing agreement, to enable the global community to cope with the escalating challenges of a changing ocean.