Regional Environment Case Study - Aleutian Islands and The Great Circle Route

(from ASMA Report 2009)


The North Pacific’s Great Circle Route is the most economic pathway for commerce between northern ports of the west coast of North America to ports in eastern Asia. The segment of this route considered in this analysis is the portion that extends from the western Gulf of Alaska, westward offshore from the Alaska Peninsula and through the Aleutian Islands including the passes at Unimak Pass and the Rat Islands. This portion of the route traverses two Arctic Large Marine Ecosystems (LMEs), the East Bering Sea LME and the West Bering Sea LME.

The East and West Bering Sea LMEs are characterized by their subarctic climate and are strongly influenced by a persistent atmospheric low pressure system that produces intense storm activity and strong ocean currents, particularly through the Aleutian Island passes. The marine and coastal environment in the region where the Great Circle Route passes includes rocky shorelines, fjords and tidal wetlands. This region seasonally supports populations of shorebirds, nesting seabirds, herring and other marine resources as well as millions of salmon during their migrations to streams of origin.

The route also passes through the U.S. Alaska Coastal Maritime Wildlife Refuge, which provides nesting and foraging habitat seasonally for millions of seabirds and year-round habitat for thousands of marine mammals. The populations of several marine species in this region are depressed, declining or otherwise considered particularly sensitive and in danger of potential extinction. Commercial fisheries in the region where the Great Circle route passes provide a large proportion of the annual landings by the U.S. fishing industry. Salmon, halibut, herring, crab, ground-fish and many other fisheries are pursued annually in the region. In 2004, Alaska fish landings were 2.43 million metric tons, valued at $US 1.17 billion.

The AMSA estimates that approximately 2,800 vessels passed along this route in 2004. Environmental impacts due to shipping, which are of the most concern in the region of the Arctic where this route passes, include the potential for vessel strikes on marine mammals, particularly the Pacific right whale; the discharge of oil and other pollutants both from routine ship discharge and accidents; and the introduction of invasive species into local ecosystems.


  •  1. Arctic Marine Shipping Assessment Report 2009

Arctic Council, 2009, Arctic Marine Shipping Assessment (AMSA), Arctic Council.©