Resource: Safeguarding Alaska's Waters

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Contrary to a common perception, the Arctic is not a pristine wilderness. Traces of contaminants can be found in its air, soil, water, and living things. Some contaminants arrive via atmospheric and oceanic circulation. Others are released locally. The most significant contaminants that originate in the Arctic are related to oil-industry emissions, spills, and fires. Their impact reaches well beyond an immediate release point, spreading throughout the ecosystem. Understanding the sources of oil contamination and its various effects has helped people design mitigation strategies.

While large tanker accidents may be the most commonly cited oil hazard, the risk is not limited to spills at sea. Once in port, tankers release toxic vapors when their cargo holds are opened. These volatile organic compounds can produce serious health effects in humans, plants, and animals. Tankers also release ballast water into port waters. Ballast water is seawater taken on board at a voyage's port of origin and used to help stabilize a ship at sea. It may contain non-indigenous aquatic organisms, including bacteria, plankton, mussels, and fish, which can disrupt the ecosystem into which they are introduced and endanger the native plants or animals.

Pipelines that transport oil over land can corrode and rupture, leaking thousands of gallons of oil into soil and streams. Drilling and extraction activities—both on-shore and off—pollute the air and alter habitat through the construction of roads, airstrips, well pads, and gravel pits. According to federal studies, more than 350 spills, explosions, and fires in the past 40 years have released more than 270,000 gallons of oil and other contaminants into Alaska's Kenai National Wildlife Refuge alone, which contains nearly 200 operating wells.

Oil-related contaminants persist for longer periods in the Arctic because low temperatures and light conditions produce lower evaporation and decomposition rates. In the marine environment, oil gets pushed further to sea by the ice pack and gets entrapped in the ice. In the tundra environment, leaked oil may remain for several years. Oil fires produce smoke clouds that are concentrated at very low altitudes. These clouds reduce solar radiation and contain particulates and other pollutants harmful to human health and to the productivity of marine and terrestrial environments.

Because environmental contaminants impact Arctic ecosystems, people who rely on it for food are also at risk. Subsistence communities that rely on the hunting of whales, polar bears, walruses, and seals are finding their fatty, high-energy food sources to be laden with industrial chemicals. Toxins are accumulating in animal tissue through biological magnification. The populations of other traditional food sources, such as caribou, are threatened because lichens, their main food source, are especially vulnerable to contamination by air pollution.

To learn more about the impact of an oil spill on Alaska's coastline and people, check out Oil Spill: Exxon Valdez, 1989, Long-Term Effects of an Oil Spill, and Oil Contamination Affects Food Web.

To learn more about the influence of environmental conditions and coastline features on how oil spills spread, check out What Happens When an Oil Spill Occurs?.

To learn more about the complex Arctic food web and the effects of oil on members of it, check out Arctic Ecosystem.

To learn more about how toxins accumulate in animals and humans, check out Contaminants in the Arctic Food Chain, Contaminants in the Arctic Human Population, and Oil Contamination Affects Food Web.

Print Questions for Discussion

• What are some of the potential environmental hazards associated with the transport of oil?
• What are some of the properties of water that make spilled oil difficult to clean up?
• What is meant by the statement, "When the tide is out, the table is set." Discuss what natural foods are on the "table," which items on the "table" are disrupted by oil, and whether the changes observed are permanent or temporary.
• In what ways might introducing a new plant or a new fish into an aquatic ecosystem affect the entire food web?
• Why is it important to have an organization like the Prince William Sound Regional Citizens' Advisory Council monitor what the oil industry is doing to avoid releasing toxic materials and contamination into the environment?