The narrow, 53-mile-wide Bering Strait is the only connection between the Pacific and Arctic oceans. The ecological significance of the Bering Strait region is tremendous. Three marine water masses flow from the northern Bering Sea into the Chukchi Sea, and eventually the Beaufort Sea, via the Bering Strait. These currents carry relatively warm and nutrient-rich water that fuels the extremely high plankton and sea floor productivity for which the region is known.
Many marine and anadromous fishes, including species important for subsistence such as Pacific salmon, use the Bering Strait. Hundreds of thousands of marine mammals of several species migrate through the strait in both spring and fall. These ice-dependent or ice-associated mammals include bowhead, beluga, and gray whales; Pacific walrus; ringed, ribbon, spotted, and bearded seals; and occasionally polar bears.
A phenomenal number of seabirds nest on the islands and coast of the strait. According to US Fish and Wildlife Service data, the Diomede Islands are nesting areas for approximately 4.7 million colonial seabirds. St. Lawrence Island has nesting areas for an additional 3.4 million birds, and the Chukotka coast, King Island, and Capes Lisburne and Thompson have over 1.5 million more. An incredible estimated 12 million seabirds nest and forage in the Bering Strait region. Little Diomede, St. Lawrence Island, Cape Lisburne, King Island, the marine area near Capes Lisburne and Thomson, and the waters of the Bering Strait are all designated Important Bird Areas.
Because the strait is the only passage between the Pacific and Arctic Oceans, all wildlife that live in the Chukchi and Beaufort Seas in the summer months funnel through the Bering Strait twice each year during spring and fall migration. Any environmental damage to the strait (such as a tanker spill) would have the potential to impact habitat used by all individuals of a population.
The Bering Strait region is covered with mostly continuous sea ice from December through April, and discontinuous ice in May, June, and November. The ice greatly constricts the passageway of what is already a narrow strait subdivided by islands and other navigational hazards. Wildlife, like ships, travel through open leads in the ice, greatly increasing the likelihood that ship traffic will encounter wildlife.
Shipping is increasing in the strait, but the route is still in its infancy. So far, no major environmentally damaging incidents have occurred. On the US side of the strait, the majority of the ship traffic stays closer to the Seward Peninsula than to the Diomede Islands, largely avoiding wildlife areas of concern. An increase in the use of satellite tracking of marine mammals and birds allows us to better understand migration patterns and timing.
Audubon Alaska has started outlining recommendations of ways to manage the shipping routes that would limit problems for wildlife. This would include scientific surveys of the wildlife and physical ocean characteristics to establish baseline information for the Bering Strait. Seasonal shipping routes, as well as possibly establishing an air-traffic-controller-style ship communication system, are other ideas. We will continue to delve into how science and mapping tools can help shape a future for the Bering Strait that preserves routes for wildlife.