U.S. Announces Extended Continental Shelf 

By Kristen Fletcher, Faculty Associate-Research, Energy Academic Group

In December, the U.S. announced the outer limits of its extended continental shelf (ECS), the portion of the continental shelf beyond 200 nautical miles from the U.S. coast, marked by territorial sea baselines. Coordinated by the multi-agency ECS Task Force, the package describes the outer limits of the U.S. ECS in the following regions: Arctic, Atlantic, Bering Sea, Eastern Gulf of Mexico, Western Gulf of Mexico, Mariana Islands and Pacific. With this announcement, the U.S. has added almost 1 million additional square kilometers of exclusive seabed rights beyond 200 nautical miles from the U.S. coast.

Using two decades of marine geophysical data, the U.S. applied provisions of Article 76 of the United Nations Convention on the Law of the Sea (UNCLOS) to delineate the outer limits of its continental shelf. While the U.S. has not ratified UNCLOS, it is U.S. policy to “act in a manner consistent with its provisions” and considers many UNCLOS provisions to be customary international law. Like other countries with an ECS, the U.S. has sovereign rights and exclusive jurisdiction in this area for the purposes of exploring, conserving and managing the living and non-living resources.

The largest area of the ECS is in the Arctic, and the announcement has significant implications there. With this extension, the U.S. claims exclusive rights to resources on and in the seabed and jurisdiction over certain activities including any form of drilling and any placement of artificial platforms. The effort aligns with the 2022 National Strategy for the Arctic Region which provides that the U.S. will “delineate the outer limits of the U.S. continental shelf in accordance with the international law as reflected in [UNCLOS].” The declaration of ECS limits by all five Arctic littoral states makes it clear that the majority of the Arctic seabed is within the national jurisdiction of one of the five states. The U.S. announcement is consistent with the 1990 maritime agreement established with Russia, while the U.S. and Canada will need to establish clear boundaries as the U.S. ECS partially overlaps with ECS areas of Canada. In addition, the U.S. ECS now partially overlaps with ECS areas of The Bahamas and Japan.

The ECS is not an extension of the Exclusive Economic Zone (EEZ); some rights that a state has in its EEZ, especially sovereign rights over water column resources (such as fish), do not apply to the ECS. The U.S. can file its submission package with the Commission on the Limits of the Continental Shelf upon UNCLOS ratification or file as a non-Party to the Convention. For now, the U.S. has issued a unilateral announcement to announce its intent to protect its rights in these areas.

LEARN MORE

• Visit the State Department ECS site at: https://www.state.gov/the-us-ecs/
• Read the Executive Summary at: https://tinyurl.com/362dhera
• Contact Kristen Fletcher at kristen.fletcher@nps.edu