San Francisco Bay is at risk of an oil spill virtually every day of the year. Millions of gallons of oil and refined products are transported across the bay each year, and more than a thousand tankers, along with countless military and container ships and recreational boats, pass under the Golden Gate. Numerous shoreline refineries, tanks, pipelines, and other facilities add to the threat of spills.

A spill the size of 1989's Exxon Valdez disaster in Alaska would reach from Mendocino to San Diego if it occurred off the California coast, and would spell disaster for wildlife here, just as it did in Alaska. In fact, a simulation by the Army Corps of Engineers showed that a spill only about one-tenth the size of the Valdez -- 1.3 million gallons -- occurring at the Golden Gate would reach the shores of the Golden Gate National Recreation Area, the Marin shoreline, Angel Island State Park, and the San Francisco waterfront in about six hours.

Oil Spills and Wildlife
On average, only about 30 percent of birds and mammals exposed to oil spills survive for more than a year. Besides killing birds, fish, sea otters, and other animals outright, oil can have other lasting effects, including reduced growth, altered feeding behavior, and lower reproductive success -- all of which make the affected animals more susceptible to disease, predators, and death.

Oil spilled in sheltered lagoons and wetlands may persist for decades in sediment, where it can continue to affect bottom-dwelling organisms and the animals that consume them. And because of the high dispersion rate of oil, even small fueling spills from recreational boats can affect large surface areas of aquatic environments.

The geography of San Francisco Bay -- islands, underwater obstructions, military zones, bridges, and ferries combine to make it difficult to navigate -- and the volume of its marine traffic put the area at high risk for spills. Two major spills (involving more than 100,000 gallons of oil) have occurred in the bay since 1984. The tanker Puerto Rican poured 1.5 million gallons of oil into bay waters that year, killing an estimated 5,000 birds. In 1988, a Shell Oil storage tank spilled 420,000 gallons, damaging wetland and estuarine areas.

The fragility of San Francisco Bay ecosystems and the area's vulnerability make bay-specific information about oil spills absolutely essential. They also make better tanker regulations crucial.

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