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Oil Spills

	Gate Bridge, By Marvin Miller
Golden Gate Bridge, By Marvin Miller
At 8:30am on November 7, 2007, a container ship struck the Bay Bridge and spilled 58,000 gallons of bunker fuel into San Francisco Bay. For information on the California Coastal Commission’s role in oil spill prevention and response, visit our Oil Spill Program.

Why did the oil move through the Bay and into the ocean the way that it did?

The California coast has two high tides and two low tides every day. On November 7, 2007, there was a high tide at 9:33am, about an hour after the spill. Until that time, the tide was rising inland. The tide then receded out toward the ocean until the next low tide at 4:44pm. Each day, about 390 billion gallons of salt water are pushed in and out of the Bay by the tides. Add to this the variable freshwater flow of the sixteen rivers that drain 40% of California’s runoff into the Bay, the ocean currents, and the winds blowing over the water. These factors are part of the reason the oil spill did not remain in one place. The Cosco Busan Unified Command Oil Spill Response has posted a video modeling the movement of the oil in the Bay.

More information about San Francisco Bay and its natural processes:

Dead bird collected from Rodeo Beach. 
	Photo: The Marine Mammal Center
Dead bird collected from Rodeo Beach.
Photo: The Marine Mammal Center
Why is oil harmful to the environment?

Oil in the water can be deadly for animals. Oil is toxic when ingested. When birds get oil on their feathers, it impairs the important waterproofing that is necessary to keep a bird warm. A bird may also lose its ability to float in the water or to fly if it is covered in oil. Oiled marine mammals may suffer from hypothermia. Oil may cause reproductive problems and genetic abnormalities in fish. Contaminants may enter the food chain and result in seafood that is unfit for people to eat.

As of November 26, 2007, 2,125 birds were either found dead or died after collection due to the Cosco Busan oil spill in San Francisco Bay. As of that date, 773 birds had been cleaned of oil and 188 of those had been released back into the Bay. Recovery workers after the 1989 Exxon Valdez incident, which spilled 11 million gallons of oil in Alaska, collected about 30,000 dead oiled birds and 1,000 dead sea otters, among other animals. Many other animals were likely affected but not recovered. In this large spill, 1,400 miles of coastline were oiled, impacting onshore and nearshore habitats.

More information on the effects of oil on wildlife:

Rodeo Beach is closed due to oil spill. 
	Photo: The Marine Mammal Center
Rodeo Beach was closed due to oil spill.
Photo: The Marine Mammal Center
What is the government doing to prevent oil spills?

After the large Exxon Valdez oil spill in Alaska in 1989, both the United States and California governments enacted laws to help prevent oil spills. The International Safety Management Code, enforced since 1998, requires ships entering U.S. ports to meet certain standards, including procedures for reporting accidents and requiring qualified crew. In 1990, the U.S. enacted the Oil Pollution Act (OPA). One of the things OPA did was require that oil tankers be double-hulled, and requires the phase out of existing single-hull tankers. A double-hull further protects a ship from damage to its cargo tank, reducing the risk of oil spilling during an accident. California enacted the Oil Spill Prevention and Response Act in 1990, which established the Office of Oil Spill Prevention and Response within the Department of Fish and Game, which is authorized to direct spill response, cleanup, and natural resource damage assessment activities, as well as regulate all private vessels over 300 gross tons (672,000 pounds) that enter California ports.

Non-tanker vessels (like the container ship that spilled oil in San Francisco) have their own regulations which are less stringent than tanker vessels. California requires a Non-Tank Vessel Contingency Plan and Certificate of Financial Responsibility, which means vessels must prove to OSPR that they have a plan in case of an oil spill and that they carry an insurance policy to cover the cost of a spill. Non-tank vessels over 300 gross tons must carry $300 million of insurance, while the requirement for tanker vessels is $1 billion.

Information on past oil spills:

What can you do to protect the Bay and the ocean?

Although oil spills such as the November 7, 2007 San Francisco Bay spill can be disastrous for people and wildlife, only about 5% of the oil in the ocean comes from big tanker spills. Much more of it comes from runoff from oil on roadways that flows into storm drains and then into waterways. This means that individuals can have a big impact on the health of our coast and ocean.

What can you do?

Classroom activities about oil spills

Oil Spill Glossary

Here are a few words you may run into when learning about oil spills:

Barrel: In the petroleum industry, a barrel of oil is 42 U.S. gallons. (California Energy Commission)


(Containment Boom)

A floating mechanical structure that extends above and below the water surface, designed to stop or divert the movement of an oil slick (a smooth area on the surface of water caused by the presence of oil). (Hazardous Materials Dictionary)


Bunker fuel oil:

A very heavy substance, left over after other fuels have been distilled from crude oil. It is used in power plants, ships and large heating installation. The oil has a high sulfur content which causes air quality concerns when burned. (California Energy Commission)


Crude oil:

A comparatively volatile liquid bitumen composed principally of hydrocarbon, with traces of sulphur, nitrogen or oxygen compounds; can be removed from the earth in a liquid state. (European Environmental Agency)


Oil spill:

The accidental release of oil, or other petroleum products usually into freshwater or marine ecosystems, and usually in large quantities. It can be controlled by chemical dispersion, combustion, mechanical containment, and absorption. (European Environmental Agency)


Water column:

A hypothetical "cylinder" of water from the surface of a water body to the bottom and within which physical and chemical properties can be measured. (EPA)