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The Bering Sea is located in the northern part of the Pacific Ocean, bounded by Alaska, northeastern Russia, and the Aleutian Islands. It is a transitional area where the water generally flows from the nutrient rich North Pacific Ocean, through the Bering Strait, into the Chukchi Sea and Arctic Ocean. The Northeastern portion of the Bering Sea is characterized by the fairly smooth gradually sloping continental shelf (less than 200m deep near the continental margin). The southwestern portion consists of an abyssal plain approximately 3700-4000m deep. Because of its sub-arctic location, the sea experiences yearly fluctuations in ice cover and is an extremely important part of the ecosystem.

Nutrient upwelling, islands, sea ice dynamics, and extensive coastlines provide excellent breeding grounds, migration stopovers, and homes for millions of fish, invertebrates, seabirds, and marine mammals. Important fish and invertebrate species include walleye Pollock, salmon (including Chinook, coho, sockeye, chum, and pink), Pacific halibut, cod, herring, crabs, and shrimp. These fish are an important food and income source for the local people. Bering Sea fisheries are also important nationally and internationally, as they provide over half of the fish for US markets annually, as well as a large portion of Russian commercial harvests.

The Bering Sea ecosystem has many resident bird species which are joined each year by millions of nesting visitors. The bird populations include several species of seabirds, waterfowl, shorebirds, and raptors. Kittiwakes, murres, auklets, and spectacled eiders are just a few of the local inhabitants, while yearly visitors include shearwaters, sandpipers, plovers, snow geese, and Sandhill cranes who migrate from as far away as Asia and Australia.

Several species of marine mammals spend all of their time in the Bering Sea including stellar sea lions, harbour seals, sea otters, dall's porpoise, and beluga whales. Many other species travel to the Bering Sea to feed or reproduce. Walruses spend the winter along the ice edge where they mate, then they follow the retreat of the ice north during the spring and summer. Polar bears also depend on the ice for feeding during the winter. Most of the Northern fur seal population breeds at one site in the Pribilof Islands. Other marine mammals that spend time in the area include several species of whales - blue, bowhead, humpback, and northern right whales- dolphins, and seals.

Because the Bering Sea ecosystem is so productive, millions of invertebrates, fish, birds, marine mammals, and humans depend on the resources found there. The dynamics of the sea have and will change naturally. However, pressures from anthropogenic sources are threatening the ecosystem. Efforts are being made to determine these threats and manage them so that all life in the Bering Sea will sustain and benefit.

The main threats to the Bering Sea are fishing, climate change, and pollution. Because the area is so productive, commercial and illegal fishing have had the largest effect on the ecosystem. The area, therefore, suffers from common problems associated with large-scale fishing: local stocks being depleted, injury and death of non-target species as a result of bycatch, and the disturbance and destruction of sea floor habitats and bottom dwelling fish, mollusks, and corals from bottom trawling.

Intensive fishing also changes the structure of the ecosystem, the result of which is not well known. For example, the collapse of the King crab fishery and the substantial increase in the number of Pollock.

Hunting, while less of a threat today, has had lasting effects on select marine mammal populations. Populations of whales, seals, walruses and sea otters were reduced in the 1800's and early 1900's. Although the Marine Mammal Protection Act and the Endangered Species Act have been put into place to protect these species, some, such as bowhead whales, sei whales, and the stellar sea lion, are still considered endangered under the Endangered Species Act.

Climate change has also been declared a threat to the Bering Sea. Warming ocean temperatures result in decreased ice cover. Changes in sea ice do not only affect marine species, such as walruses and polar bears, it also affects the local people's ability to hunt from the ice. Increasing ocean temperatures will also have an effect on the marine life itself and each species will react differently. Some may have an explosion of numbers (algae blooms), while others may suffer and become endangered or extinct (low salmon runs).

Pollution in the Bering Sea comes from many sources; debris and petroleum from ships and fishing boats, chemicals from industrial regions and mining operations, nuclear waste from old nuclear power plants on the Russian coast, and oil exploration operations. As with other polar regions, the Bering Sea suffers from the long range transport of pollutants from developed regions that make their way to the sea in precipitation and run off. The introduction of contaminants is particularly problematic in this region, because the cold climate prevents contaminants from breaking down quickly. As well, the extensive food web, that includes slow-growing long-lived species, allows contaminants such as heavy metals to accumulate and be magnified in the higher trophic levels including humans.

Research is being done to determine how these threats are affecting the Bering Sea ecosystem, but there is still much to be learned. It will take the co-operation of many stakeholders to address the issues and protect the Bering Sea. Only with a combined effort can sustainable practices be implemented and the viability of the Bering Sea preserved.

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