to continue to grow at a similar rate in the coming decade. Most of these ships use the North Pacific Great Circle Route—the most direct transit route between Pacific coast ports of the United States and Asia—which brings them through or near the Aleutians. Unimak Pass at the eastern end of the Aleutian Islands sees about 4,500 vessel transits annually.
Growth of commercial traffic in the region is expected because of both an increase in maritime trade and expanded economic activity in the Arctic that will open up new shipping routes through the Aleutians. Economic activity is expected to increase in the Arctic as the southern extent of the summer ice pack thins, enabling ice-capable ships to travel through the region. According to a recent report of the National Research Council (NRC), “Those deploying fishing fleets, cruise ships, mining, and the associated ore transit ships, as well as petroleum recovery and tanker ship transport, anticipate increased operations in the region. When current orders for ice-strengthened tankers have been filled, the worldwide fleet of these vessels will double in number” (NRC 2007, 5). Some of these tankers will be transiting through the Aleutian region.
Given current trends in both maritime trade and climate change, growth in vessel traffic in the Aleutian Islands is expected to continue for the foreseeable future. All other factors remaining constant, this growing traffic will result in an increased risk of vessel accidents and spills.
In addition to commercial ships that transit the region, fishing vessels, ferries, cruise ships, tugs, and barges operate in and around the Aleutians. Because some fishing grounds are at the north end of Akun Island, fishing vessels must cross the commercial traffic lanes. Moreover, two or three large cruise ships operate annually in the Aleutians, 10 cruise ships visit Dutch Harbor every summer, and about 20 trips are made each year via the Alaska Marine Highway. These numbers are also expected to increase, adding more north–south vessel traffic through the region.
The Aleutian Island chain, consisting of approximately 300 volcanic islands, extends westward about 1,200 miles from the southwestern tip of the Alaska Peninsula toward the Kamchatka Peninsula and occupies an area of about 6,820 square miles. The region is