Pribilof Islands (prĬb´Ĭlŏf´), group of four volcanic islands, off SW Alaska in the Bering Sea, c.230 mi (370 km) N of the Aleutian Islands; explored and named in 1786 by Gerasim Pribilof, a Russian navigator. The larger islands, St. Paul and St. George, are famous as the breeding place of the Alaska fur seal. The islands, part of the 1867 U.S. purchase of Alaska, became a seal reservation in 1868; they are administered by the U.S. Bureau of Fisheries. Prior to 1911, competition and ruthless hunting methods threatened extinction of the seals. At that time, the United States, Great Britain, Japan, and Russia entered into the North Pacific Sealing Convention, giving the United States the right to enforce the provisions of the convention (see Bering Sea Fur-Seal Controversy under Bering Sea). Japan withdrew from the convention in 1941. Under protection, the seal herd has greatly increased. Blue and white foxes are native to the islands. The Aleuts, brought to the islands in the late 1700s by the Russians, make a living by processing the seal and fox furs.