Why the oceans matter

Life on Earth began in the ocean, and it remains essential today. The ocean covers about 72% of the planet, spanning roughly 140 million square miles.

Throughout history, it has been a source of food, a route for trade, a space for exploration, and a force that both connects and separates people.

Even today, most of the world’s population lives within 200 miles of the coast, showing how closely human life is tied to the sea.

 

How the rules of the sea developed

For centuries, the oceans were governed by the idea of “freedom of the seas.” This principle, dating back to the 17th century, allowed countries to control only a narrow strip of water along their coasts. Beyond that, the ocean belonged to no one and was open to all.

By the mid-20th century, this system was no longer enough. New challenges emerged:

  • competition for resources like fish, oil, and minerals,
  • rising pollution,
  • tensions between coastal states and distant fishing nations,
  • increased maritime traffic,
  • and new opportunities to exploit seabed resources.

These pressures made it clear that shared rules were needed to prevent conflict and ensure fair use.

 

United Nations Convention on the Law of the Sea (UNCLOS)

In the mid-twentieth century, many States recognized the need to set down rules for all ocean areas and all uses of the ocean and its resources, through a comprehensive treaty. After years of negotiation, the United Nations Convention on the Law of the Sea (UNCLOS) was adopted in 1982 and entered into force in 1994.

It is often called the “constitution for the oceans” because it sets out the global legal framework for how oceans are used.

The Convention includes:

  • rules on maritime boundaries,
  • rights and duties of states,
  • protection of the marine environment,
  • scientific research,
  • and dispute settlement.

It also established key institutions like:

 

Protection of Biodiversity and Climate Change
A harbor seal at the Elkhorn Slough Ecological Reserve, an estuary located along Monterey Bay in California, United States. UN Photo/Mark Garten

 

Protection the ocean and its biodiversity

UNCLOS places strong emphasis on protecting the marine environment. It defines marine pollution as any human activity that introduces substances or energy into the ocean in ways that harm marine life, human health, economic activities like fishing, or water quality.

This definition also includes the impacts of climate change, such as greenhouse gas emissions.

The convention requires States to:

  • protect and preserve the marine environment,
  • prevent and reduce pollution from all sources,
  • safeguard fragile ecosystems,
  • and protect endangered species.

They must also cooperate at both global and regional levels. 

UNCLOS is supplemented by three implementing agreements, namely the 1994 Part XI Agreement, the 1995 United Nations Fish Stocks Agreement (UNFSA) and the BBNJ Agreement (see below), which all include provisions on the protection and preservation of the marine environment.

 

 

Broader UN efforts on ocean protection

Ocean governance involves multiple UN agencies and agreements. While talking about UN bodies, the most important ones are:

The international legal framework for the protection and preservation of the marine environment also includes a number of international instruments specifically addressing the protection of marine biodiversity and ecosystems, such as the United Nations Convention on Biological Diversity, the Convention on International Trade in Endangered Species of Wild Fauna and Flora, the Convention on the Conservation of Migratory Species of Wild Animals, and the Kunming-Montreal Global Biodiversity Framework, that includes meassures to halt and reverse nature loss in all ecosystems, including the ocean. 

Other key initiatives include:

  • the 2030 Agenda for Sustainable Development, especially Goal 14 (Life Below Water),
  • UN Decade of Ocean Science (2021–2030), aimed at improving knowledge to support sustainable ocean use.

Oceans and climate change

The ocean plays a critical role in regulating the Earth’s climate. Enhanced international cooperation and coordination is key to addressing the effects of climate change on the ocean. Several international instruments contain provisions to that effect. As a result, major global agreements such as:

  • UN Framework Convention on Climate Change,
  • and the Paris Agreement (2015)

include measures related to ocean protection and climate impacts.  

 

Efforts for a High Seas Treaty, a historic new commitment on marine biodiversity

More than two-thirds of the ocean lies beyond national borders. These areas are rich in life, but have long lacked protection.

After two decades of negotiations, a new agreement entered into force in January 2026. Known as the High Seas Treaty (BBNJ Agreement), it marks a major step toward protecting marine life in international waters and the seabed.

What it does:

  • Protects marine genetic resources and ensures benefit-sharing
  • Creates marine protected areas
  • Requires environmental impact assessments
  • Supports capacity-building and technology transfer

The agreement is already legally binding for 81 countries. More can still join, and the more that do, the stronger it becomes.

The real challenge is implementation. That means enforcing the rules, holding actors accountable, and turning commitments into action.

If fully applied, the treaty can help tackle the triple planetary crisis: climate change, biodiversity loss, and pollution.

 

Sustainable fisheries: a major challenge

Marine resources are vital for food, livelihoods, and economies. However over one-third of fish stocks are overexploited, illegal fishing remains widespread, and climate change is damaging marine ecosystems.

UNCLOS, together with the 1995 UN Fish Stocks Agreement, promotes:

  • responsible fishing,
  • international cooperation,
  • and measures to combat illegal, unreported, and unregulated fishing.

 

Shipping and marine pollution

Shipping is essential to global trade but contributes to pollution.

The IMO has adopted regulations to:

  • improve energy efficiency,
  • reduce emissions,
  • and move toward net-zero greenhouse gas emissions by 2050.

It also regulates sensitive areas like the Arctic and Antarctic through the Polar Code, ensuring safer and more environmentally responsible shipping.

 

Polar Code

The safety of ships operating in the harsh, remote and vulnerable polar areas and the protection of the pristine environments around the two poles have been a matter of concern for IMO over many years. Many relevant requirements, provisions and recommendations have been developed by IMO, in light of the unique risks that ships are exposed to in the Arctic and Antarctic environments.

In this connection, in January 2017, IMO's International Code for Ships Operating in Polar Waters (Polar Code) entered into force. The Polar Code covers the full range of design, construction, equipment, operational, training, search and rescue and environmental protection matters relevant to ships operating in the inhospitable waters surrounding the two poles. The Polar Code was an important regulatory development in international shipping, alongside a range of regulatory developments relating to maritime and supply chain security and environmental issues.

 

Piracy and maritime security

MONUSCO peacekeepers land at beach to guard against piracy
MONUSCO peacekeepers land at beach to guard against piracy in the Democratic Republic of the Congo. UN Photo/Sylvain Liechti

Piracy remains a serious issue in regions such as the Horn of Africa and the Gulf of Guinea.

Its impacts include:

  • risks to human life,
  • disruption of global trade,
  • increased costs of transportation,
  • and environmental damage.

The United Nations Office on Drugs and Crime, through a program called the Global Maritime Crime Programme, helps African countries deal with crimes at sea, especially piracy. They do this by helping countries prosecute and imprison piracy suspects; training police, coast guards, and legal workers; teaching countries how to better enforce laws at sea; and supporting places like Somalia, Kenya, and Ghana with hands-on help. Overall, it has strengthened maritime security and the rule of law in challenging environments.

The International Maritime Organization (IMO) also helps countries develop national and regional responses to piracy and maritime crime when they ask for support. It runs projects that improve cooperation between countries and provides training and help in strengthening laws. The IMO has also helped create agreements in regions like East and West Africa, allowing countries to coordinate their efforts and respond more effectively to piracy. 

 

 

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