A meridian argument still divides Alaska and Yukon waters
The Beaufort Sea is an Arctic Ocean margin north of Alaska, Yukon, and the Northwest Territories, named for hydrographer Sir Francis Beaufort. The Mackenzie River is its chief freshwater pulse, yet ice still seals most months even as late-summer open water widens with Arctic warming.
The Beaufort Sea lies west of the Canadian Arctic Archipelago, and the International Hydrographic Organization bounds it with a line from Point Barrow in Alaska to Lands End on Prince Patrick Island, then down past Banks Island to Cape Bathurst on the mainland. Canada's longest river, the Mackenzie, enters the Canadian sector west of Tuktoyaktuk, one of very few permanent settlements on the coast.
Ice rules most of the year. Traditionally only a strip up to 100 kilometres wide opened near shore in August and September, but Arctic warming has vastly enlarged the late-summer open water. The sea used to be a key nursery for Arctic ice: floes could circle for years in the Beaufort Gyre, its dominant current, thickening into tough multi-year ice.
People are few, and claims of coastal settlement some 30,000 years ago have been largely discredited. Oil and gas fields under the shelf, such as Amauligak, were found between the 1950s and 1980s, and exploring them has become the main human activity. Fishing and hunting of whales and seals remain local and non-commercial, which helps explain why one of the largest beluga populations lives here; as of 2016 the eastern hunt was judged sustainable. The United States adopted a cautious fisheries plan in August 2009, and Canada has created marine protected areas around the Parry Peninsula and at the Mackenzie delta to safeguard habitats used by the Inuvialuit.
A wedge of water remains in dispute. Canada says the sea boundary with Alaska should follow the 141st meridian straight out for 200 nautical miles, extending the land border, a position rooted in the 1825 Treaty of Saint Petersburg between Britain and Russia, which Canada inherited. The United States argues for a line perpendicular to the coast, equidistant from both shores, and the two approaches leave a contested triangle.
Source: Beaufort Sea
