The Bering Sea is named after a Danish navigator in the Russian
Navy, who explored the area in 1741. It lies between mainland
Asia and North America, and is bounded by the Aleutian Islands
to the south and linked to the Arctic Ocean in the north by the
narrow Bering Strait. There is a flow of cold Arctic water south
through this strait, feeding a counterclockwise circulation. The
main freshwater input is the Yukon River, which has deposited an
extensive delta at its mouth. The Bering Sea is one of the
world’s richest fisheries, helping Alaska account for about half
of the total US fish and shellfish catch. Harbor seals and gray
whales also take advantage of these productive waters. In
contrast to the deep ocean basin beneath the southwestern half
of the sea, the broad continental shelf in the northwest is very
shallow. Much of this area formed a land bridge during the last
ice age, when sea levels were up to 390 ft (120 m) lower than
they are today. This route was ice-free for extended periods,
allowing sever