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Pearl and Hermes Atoll lies about 216 nautical miles (400 km) east-southeast of Midway Atoll and approximately 1,080 nautical miles (2,000 km) northwest of Honolulu. It is a huge oval coral reef within several internal reefs. It is the second largest (about 1,166 km2 to depths of 100 meters) among the six atolls in the Northwestern Hawaiian Islands. (Original source and more information: NOAA National Ocean Service Image Gallery)

Marine Environment

The Office of Ocean and Polar Affairs is responsible for advancing and promoting U.S. economic, security, and environmental interests by advancing international efforts to conserve and sustainably use the ocean and its resources. OPA supports efforts to conserve marine biodiversity, to monitor and address the impacts of ocean acidification and climate change on the ocean, to reduce land and sea-based sources of marine debris, and to coordinate international oil spill prevention and response. It also coordinates U.S. participation in international agreements and treaties involving the protection of the marine environment, such as those for the prevention of pollution from ships and from the dumping of wastes and other matter from ships.

U.S. Policy on Sea-level Rise and Maritime Zones

On September 29, 2022, the United States announced a policy on sea-level rise and maritime zones.

U.S.-Canada Fourth Joint Mission To Map the Continental Shelf in the Arctic Ocean Views of the U.S.-Canada fourth joint mission to map the continental shelf in the Arctic Ocean in August and September 2011. The 2011 joint mission employed the flagship icebreaker from each country, the U.S. Coast Guard Cutter Healy and the Canadian Coast Guard Ship Louis S. St-Laurent (LSSL), with each ship performing different functions and one ship breaking ice for the other.[State Department photo/ Public Domain]

Law of the Sea

Law of the Sea Convention

The Office of Ocean and Polar Affairs (OPA) is responsible for developing, coordinating, negotiating, and implementing U.S. foreign policy with respect to the law of the sea.  The Law of the Sea Convention  sets forth a comprehensive legal framework governing uses of the ocean. Adopted in 1982 and substantially modified by a 1994 Agreement  relating to its deep seabed mining provisions, the Convention has been in force since 1994 and currently has more than 165 parties. The United States is not a party to the Convention.

U.S. Extended Continental Shelf

OPA is responsible for overseeing the U.S. Extended Continental Shelf (ECS) Project, which is designed to establish the full extent of the continental shelf of the United States, consistent with international law.  The ECS is that portion of the continental shelf beyond 200 nautical miles from shore.  Knowledge of the exact extent of the U.S. ECS and an improved understanding of its resources will promote economic prosperity and enhance stewardship of our natural resources.

Maritime Boundaries

The Office of Ocean and Polar Affairs provides support for negotiation of maritime boundary agreements to which the United States is a party.

Limits in the Seas

OPA examines coastal States’ maritime claims and/or boundaries and assess their consistency with international law.

A U.S. Coast Guard cutter guards a marine port. August 2003. [Pixaby]

Maritime Security

Maritime Security and Navigation

The Office of Ocean and Polar Affairs (OPA) works with U.S. agencies and international and nongovernmental organizations to coordinate U.S. foreign policy on maritime security.  Key among these groups is the International Maritime Organization (IMO), a specialized agency that seeks to foster international cooperation on technical matters affecting international s​hipping.  U.S. maritime security policy facilities global commerce and preserves the freedom of the seas for legitimate navigation and other lawful activities.  OPA coordinates maritime security efforts, among other things, on piracy, particularly off the coast of Somalia, in the Gulf of Guinea, and in the waters of Southeast Asia, maritime domain awareness, and the U.S. Freedom of Navigation (FON) Program.

U.S. Department of State Flickr, Scientists analyze microscopic ocean organisms during a Foreign Press Center Tour to Norfolk, VA. July 2016

Marine Science

The Office of Ocean and Polar Affairs is responsible for developing, coordinating, negotiating, and implementing U.S. foreign policy with respect to marine science and research.  This includes oversight of the State Department’s marine scientific research clearance program, which grants consent for foreign scientists to conduct research in U.S. waters and obtains consent from foreign governments for U.S. scientists to conduct research in foreign waters.

OPA also facilitates international scientific exchange, promotes global marine science and research, and coordinates U.S. participation in international organizations, regional organizations, and multilateral agreements involving marine science and research.

You can find further guidance on Marine Scientific Research Authorizations here.

A polar bear roams the Arctic tundra. November 2013. [Pixaby]


The Office of Ocean and Polar Affairs develops and implements United States foreign policy as it relates to the Arctic region.  It also leads United States participation in the Arctic Council, an intergovernmental forum of the eight Arctic States (Canada, Denmark, Finland, Iceland, Norway, Russia, Sweden, United States) with the close advice of the Arctic indigenous peoples represented through six organizations known as “Permanent Participants.”

​United States Arctic policy focuses on six overarching policy objectives: 1) meeting national security needs; 2) protecting the Arctic environment and conserving its biological resources; 3) promoting environmentally sustainable natural resource management and economic development; 4) strengthening institutions for cooperation among the eight Arctic nations; 5) involving Arctic indigenous people in decisions that affect them; and 6) enhancing scientific monitoring and research on local, regional, and global environmental issues.

Emperor Penguins guide their young across the frozen tundra of Antarctica. October 2008 [Pixaby]


The Office of Ocean and Polar Affairs develops and coordinate​s U.S. policy affecting the Antarctic region, working to ensure that the Antarctic continues to be reserved for peace and science and to conserve marine life in the Southern Ocean. OPA leads the U.S. delegation to the annual Antarctic Treaty Consultative Meeting, and works closely throughout the year with the National Science Foundation, which runs the U.S. Antarctic Program, other USG agencies, and key industry and environmental stakeholders. The United States has the greatest number of scientists and tourists visiting Antarctica each year. OPA pays particular attention to geopolitical issues. Climate change research that can only occur in Antarctica, increasing tourism to the continent, and expanding maritime protected areas are significant policy issues that we perennially address. ​OPA leads the U.S. delegation to the Commission for the Conservation of Antarctic Marine Living Resources, which manages fisheries and marine conservation in Antarctica and the Southern Ocean. It also periodically leads inspections of Antarctic facilities under the Antarctic Treaty.

U.S. Department of State

The Lessons of 1989: Freedom and Our Future