Every Bird Matters
news and views from international bird rescue

November 7, 2017

Cosco Busan Oil Spill: 10th Anniversary of Disaster on San Francisco Bay

This month is the somber 10-year anniversary of one of the worst environmental disasters to befall the San Francisco Bay. On November 7, 2007, an oil spill near the Bay Bridge left thousands of oiled birds dead and dying.

More than 50,000 gallons of heavy bunker fuel oil leaked into the bay on that day. Carried by the bay’s turbulent tidal currents, the oily mess coated beaches and shorelines throughout the Bay, past the Golden Gate Bridge, onto Marin County beaches. Within days we and our partners treated over 1,000 birds at our SF Bay–Delta wildlife center. Read report from 2007

The oil spill occurred when the Cosco Busan container ship collided with the San Francisco Bay Bridge. The collision dumped 54,000 gallons of oil called “bunker fuel” into the Bay. The spill oiled 70-miles of Bay Area shoreline. During the aftermath of the spill, at least 3,000 live and dead birds were collected. Some biologists speculate that the number of affected birds was even greater, with reports that up to 3x as many birds may have been oiled and then succumbed to death outside the bay. This event occurred during a busy migration time for birds moving through the area.

The majority of affected seabirds included: Surf Scoters, Clark’s and Western Grebes, and Eared and Horned Grebes.

All oil spills are extremely toxic to marine life but especially bunker fuel spills. The thick oil causes the natural insulation in the bird’s feathers to break down, resulting in the bird’s inability to thermoregulate, which can lead to hypothermia and even death. For birds that float and feed through a spill, it’s a death sentence if not rescued quickly. In addition to having problems thermoregulating, once oiled, the birds will spend most of their time trying to preen the oil out of their feathers and thus ingest the oil. Weakened, they will often beach themselves and fall prey to predators or die from oil toxicity. See: How Oil Affects Birds

Thousands of Bay Area citizens moved to volunteer and gave time. With this contribution hundreds of birds were rehabilitated and released.

While we are fortunate to have not had a large spill in the Bay Area since 2007, we remain vigilant and prepared to respond to such an event at a moment’s notice.

Other media reports

Cosco Busan oil spill – 10 years later (Golden Gate Audubon)

Richardson Bay islands’ revival following Cosco Busan Spill (Marin IJ)

Ten years after the Cosco Busan oil spill: Preparedness and response improved; $30M in environmental restoration ongoing (Cosco Busan Trustee Council)

Oiled Ring-billed Gull. Photo: Glen Tepke

Washing an Eared Grebe during the Cosco Busan Oil Spill response. Photo by Russ Curtis/International Bird Rescue

 

More than a 1,000 oiled birds, including a pool full of Scoters, were treated at the San Francisco Bay-Delta wildlife center. Photo by Russ Curtis/International Bird Rescue

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