9.4 Managing and conserving ocean resources

Protecting resources that exist, in large part, as a common-pool resource would be challenging under any circumstances. Simultaneous pressures from increasing pollution, increasing human population, and accelerating climate change increase the need for a sustainable approach to these important resources.

Regulatory approaches to conservation and management of marine natural resources

Within their exclusive economic zones – in the waters within 200 nautical miles of their coasts – nations manage and conserve natural resources as they choose. They can exclude harvest of sea organisms by other nations, set their own harvest levels, control gear use for harvest, establish protected areas, and so forth. Other nations are typically excluded from mining minerals and fossil fuels.

Certification programs for sustainable seafood, mentioned in Chapter 7, provide additional support for efforts to use marine resources sustainably. These include international NGOs such as the Marine Stewardship Council and the Global Seafood Alliance’s Best Seafood Practices, as well as national-level efforts such as Fair Trade USA. An umbrella organization, the Certification and Ratings Collaboration, makes available a data tool that compiles information both on environmental sustainability and human rights/social responsibility aspects of fisheries.^[1]

Mining and drilling under the high seas

Mining for minerals and petroleum products under the high seas is subject to control of the International Seabed Authority, under UNCLOS. Although the ISA has issued permits for exploration for mineral deposits, no mining has yet been allowed.  Existing rules require that mining companies wishing to work in the high seas must partner with a UN member state, but no further regulatory structure exists. The most recent round of talks aimed at determining how mining might proceed broke off in July 2025, without any resolution.

Because the US has not signed UNCLOS, it is free to ignore the standstill in regulatory work at the International Seabed Authority and proceed to mine as it pleases. In the past, the US has followed UNCLOS processes, but under the present administration, it has expressed strong interest in developing deep sea mining. It is considering mining within the US EEZ around American Samoa, despite Samoan resistance, and is exploring two requests from companies seeking to mine in international waters with US partnership.^[2]

Harvest of living resources on the high seas

On the high seas, the UN Convention on the Law of the Sea (UNCLOS) is the overarching authority on management of living resources, but specific treaties provide a patchwork approach to sustainable management. Harvest in the Southern Ocean, the waters surrounding Antarctica, is managed separately, by the Convention for the Conservation of Antarctic Marine Living Resources, as part of international agreements in the Antarctic Treaty System.

Under UNCLOS, the management of fish stocks of species that breed in freshwater but live mostly in salt water, including the high seas, is the responsibility of the nations in whose freshwater the species breed. Thus, the US and Canada are responsible for management of the salmon that breed in rivers on the east and west coasts of North America.

Fully marine species that migrate within and across the high seas (highly migratory species) and whose ranges include the high seas as well as the waters of multiple nations (straddling stocks) are managed by the nations in whose freshwater the species breeds. Thus, Canada and the US manage the salmon stocks that breed in the coastal rivers of North America.

A variety of specific fish management systems are enabled under UNCLOS. For example, the International Commission for the Conservation of Atlantic Tuna (ICCAT) protects tuna, species related to tuna, and highly migratory sharks and rays in the Atlantic Ocean and adjacent seas. It also has measures to reduce bycatch of sea turtles and seabirds in the fisheries it oversees.

ICCAT has had some successes, but it has also been criticized for failing to act quickly and strongly enough to protect the stocks for which it is responsible. A single, high-value tuna, which can weigh as much as 600 lbs (270 kg) can bring over USD 1 million at auction, for sushi. As a result, the economic pressure is high to allow fishing on these stocks and illegal fishing pressure is also high. Nevertheless, some recovery has occurred.

The most recent effort at protecting living marine resources under UNCLOS is the ponderously named Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction, abbreviated as BBNJ, which required almost 20 years of negotiation to create. It was ratified by the 60th member state in September 2025 and came into effect at that point, for those nations that have ratified it. The agreement, which is informally called the High Seas Treaty “establishes legally binding rules to conserve and sustainably use marine biodiversity, share benefits from marine genetic resources more fairly, create protected areas, and strengthen scientific cooperation and capacity building.”^[3]

Marine Protected Areas (MPAs)

Under UNCLOS, nations are empowered to create Marine Protected Areas (MPAs) in their territorial waters and within their EEZs. In addition to protecting biodiversity, protection of coastal ecosystems and the seabed in MPAs helps to ensure that sequestered carbon remains undisturbed and can continue to accrete, helping to mitigate climate change.

The International Union for the Conservation of Nature (IUCN) reports that slightly more than 6% of world oceans is protected in MPAs, but less than 2% is protected at a level that prohibits taking of resources (living and mineral).^[4] The IUCN also reports that MPAs are typically understaffed and underfunded, making it more difficult to protect resources from threats including climate change.

No marine protected areas have been created in the high seas under UNCLOS, but an area three times the size of California has been protected in the Ross Sea, on the coast of Antarctica, under a separate treaty, the Convention for the Conservation of Antarctic Marine Living Resources, that governs the Southern Ocean. The Ross Sea Marine Protected Area is quite large, but its creation was contentious, and it is more than 40% smaller than its originally proposed size. All biodiversity is protected in 72% of the area, which is managed as a no-take zone.^[5]

Knowledge Check

Take a moment to complete the short quiz below to assess your understanding of this section. Read each question carefully and refer to the section content as needed. This quiz is not graded – it’s simply an opportunity for you to reflect on what you’ve learned and reinforce key concepts.