A coastal country’s rights over ocean resources now generally reach 200 nautical miles out, roughly 230 land miles. The process behind the treaty that set that limit began with a 1967 speech at the United Nations. Maltese ambassador Arvid Pardo told the General Assembly that the minerals lying on the deep seabed, beyond any nation’s existing reach, should be the common heritage of mankind.
Why a seabed speech changed how far a coast reaches
Pardo’s speech landed at a moment when the old rules of ocean law were already under strain. In the decade before he spoke, the number of independent states had roughly doubled, and most of the newly independent nations had not ratified the 1958 Geneva Conventions that were then meant to govern the sea. Those states wanted a bigger share of the fish and minerals off their own coasts, and several South American countries had already started claiming exclusive rights far past the traditional territorial sea.
The UN General Assembly responded to Pardo’s argument by voting, in 1970, to declare the seabed beyond national jurisdiction the “common heritage of mankind” and to convene a conference on the law of the sea. That conference, the Third United Nations Conference on the Law of the Sea, opened procedurally in New York in 1973 and began substantive negotiations in Caracas in 1974.
Why the treaty took until 1982 to sign
The talks ran for most of a decade. The conference worked without a draft text and without the input of legal experts who had shaped the earlier 1958 conventions. Instead, negotiators built the treaty issue by issue, aiming for a single “package deal” that everyone could accept together, rather than voting through individual points. The result, opened for signature at Montego Bay, Jamaica, on 10 December 1982, runs to more than 400 articles across nine annexes, which the UN’s own account calls the most extensive act of codification any UN process has completed. It took until 14 November 1994 to gather enough ratifications to enter into force, and as of 2008 it bound 154 states plus the European Community.
What the 200-mile zone actually grants
The treaty created the exclusive economic zone, or EEZ, which starts where a country’s 12-nautical-mile territorial sea ends and reaches out to 200 nautical miles from the coast. Inside that zone, a coastal state holds sovereign rights to explore, exploit, conserve and manage the natural resources of the seabed, the subsoil and the waters above. It also gets jurisdiction over artificial islands and installations built in the zone, and over marine scientific research and environmental protection there.
The United States did not wait for the treaty to take effect. A presidential proclamation claimed a 200-nautical-mile EEZ for the country in March 1983, covering the mainland coast along with Puerto Rico, Guam, American Samoa, the US Virgin Islands and the Northern Mariana Islands. That claim alone covers more than 3.4 million square nautical miles, an area larger than the land mass of all 50 states combined, which NOAA counts among the largest EEZs anywhere.
Ocean rights outran ocean knowledge
The gap between the size of these zones and how well anyone has studied them is stark. NOAA reports that only about 40% of the US EEZ has been mapped, and far less of it has been fully characterised, which leaves most of the resources inside America’s own economic zone poorly understood. NOAA says the zone holds seafood, critical minerals, medicines and places of real ecological and conservation value. The federal government has drawn up several strategies to map, explore and characterise it.
