Canada maintains that this treaty is extensible from the land into the Beaufort Sea along the meridian. The United States rejects this extension and instead asserts a boundary line based upon equidistance, although its position is somewhat undermined by its acceptance in 1867 of similar treaty wording and a similar interpretation under the treaty whereby it acquired Alaska. Both the U.S. and Canada agree that they are bound by the 1958 Convention on the Continental Shelf; and they both agree that the boundary should be "equitable", as determined by the International Court of Justice. They differ on what should be deemed "equitable". The U.S. contends that "equidistance is an appropriate principle for determining a maritime boundary where there are no special circumstances in the area and when equidistance results in a boundary in accordance with equitable principles". Canada contends that an equidistance principle does not result in an equitable boundary, because distortion would occur. The coast of Yukon is concave, whereas the coast of Alaska is convex; and thus an equidistance principle would result in a significant extension of the U.S. possession. This dispute has taken on increased significance due to the possible presence of natural reserves within the wedge, which according to Canada's National Energy Board may contain of gas, which would cover the national consumption for 20 years, and more than of oil. Because of this, Canada argues that "special circumstances" apply to this border, a position that the U.S. rejects. This dispute is in this respect a mirror image of the dispute between the U.S. and Canada over the Gulf of Maine, where the U.S. argued for "special circumstances" and Canada argued for the equidistance principle. (In that latter dispute, both of those arguments were rejected, and the border was drawn based upon geometric principles taking into account geographic factors.) Neither the U.S. nor Canada has pressed for a swift resolution for the matter, or arbitration at the International Court of Justice, however; and the two have in the meantime cooperated in several measures aimed at preserving the maritime environment.