in the water and seabed within a 200-mile Exclusive Economic Zone (EEZ). However, Article 76 of the Convention allows coastal states to extend their sovereign rights up to 350 nautical miles from their coastline if they can prove that the Arctic seafloor's underwater ridges are an extension of the country's own continental shelf. Nations have ten years following their ratification of UNCLOS within which to submit their claims to extended continental shelves. In 2001 Russia was the first Arctic littoral state to submit its claim. The UN Commission on the Continental Shelf requested a revised claim with more scientific data supporting their claim, and Russia planned to file additional data in 2013. Denmark and Canada dispute ownership of Hans Island in the Nares Strait between Ellesmere Island and Greenland. On April 27, 2010, Norway and Russia announced an end to their 40-year arctic demarcation dispute in the Barents Sea. Future joint energy development is expected. Maritime boundaries between Canada and the United States in the Beaufort Sea and between Canada and Denmark in Baffin Bay remain under dispute. Denmark (Greenland), Russia and Canada may have competing extended continental shelf claims over the Lomonosov Ridge, an underwater mountain chain crossing the central Arctic basin. Shipping and transport Global warming has had a greater impact on summer sea ice in the Arctic than previously estimated. Based on the recent studies, the Arctic will be largely ice-free during the summer sometime between 2020 and 2050. One 2011 Cambridge University study predicted that the Arctic would be free of summer ice by 2015. No models predict that the winter sea ice will disappear during this century. An ice-free Arctic has major strategic and economic ramifications for global shipping, as vessels will potentially be able to traverse the Arctic Ocean. Trans-Arctic shipping routes could shorten distances between northern Europe and northern China by up to 4,000 nautical miles and reduce shipping times by up to two weeks. All cargo ships in Arctic waters over 500 tonnes are subject to the mandatory requirements for safety and protection of the environment under the Polar Code. Arctic natural resources Fisheries Key Arctic fishery regimes include: The International Commission for the Conservation of Atlantic Tunas (ICCAT) The bilateral (Canada and the United States) International Pacific Halibut Commission (IPHC) The bilateral (Russian Federation and the US) Intergovernmental Consultative Committee (ICC) The Northwest Atlantic Fisheries Organization (NAFO) The North Atlantic Salmon