Mystery substance now found on seabirds on west side of Bay 

click to enlarge East Bay Parks rangers 37 year old Chris Benoit (green hat) and 24 year old Joel Eisler (tan hat) place a live soiled bird into a carry crate to transport it from the Hayward shoreline of the San Francisco Bay to a mobile stabilization hospital. - MIKE KOOZMIN/THE S.F. EXAMINER
  • mike koozmin/the s.f. examiner
  • East Bay Parks rangers 37 year old Chris Benoit (green hat) and 24 year old Joel Eisler (tan hat) place a live soiled bird into a carry crate to transport it from the Hayward shoreline of the San Francisco Bay to a mobile stabilization hospital.

The mystery surrounding the hundreds of seabirds found coated in an unknown, gooey substance along the eastern San Francisco Bay shoreline took a twist this week with the discovery of several more birds along the San Mateo County coast to the west.

Also on Wednesday, the agency released a statement via its Twitter account saying scientists had ruled out polyisobutylene, or rubber, as the substance.

The California Department of Fish and Wildlife on Tuesday morning began testing the mysterious substance, as well as water samples, to determine the sticky material's chemical compound, department spokesman Andrew Hughan said. Officials were also performing necropsies on dead birds.

Soiled birds have been dying as a result of hypothermia. Once coated in the substance, the birds are no longer shielded from the elements and cannot fly to find food.

It was not known when the test results would be released, though officials have determined that the substance is not petroleum.

"We're working as diligently and quickly as we can," Hughan said.

As of Tuesday afternoon, more than 360 birds -- primarily surf scooters, buffleheads and horned grebes -- had been found since Friday by volunteers with bird and wildlife rescue organizations, as well as by state Department of Fish and Wildlife employees.

Two of the birds were picked up in Foster City along the Peninsula on Sunday, while the rest have been found along the Alameda County coast.

Of the collected birds, 280 were transported to the International Bird Rescue center in Fairfield, where 242 were being stabilized. Thirty-eight birds had died while being transported or upon arrival at the center, and 60 birds had been washed, said Russ Curtis, technology manager for International Bird Rescue.

Curtis described the substance as clear, odorless and similar to rubber cement.

"But it mats down the feathers," Curtis said. "Depending on how far they got into it, their feathers are really sticky."

The International Bird Rescue was using baking soda, vinegar and "copious amounts of Dawn dishwashing liquid" to clean the birds, Curtis said.

Officials on Tuesday remained stumped as to the origin of the substance, which appears to be nontoxic to humans.

"If you were to look at possible places of starting points, the San Francisco Bay is kind of tricky because it's got a lot of different movements, between the tidal flow and currents," Curtis said. "It seems like it may have started in the East Bay."

It also was unknown how far the substance has spread.

Though two birds were found in Foster City coated in the substance and another three were spotted but not captured, volunteers searching the Peninsula coast did not find any evidence of the mysterious material.

"It appears that [the birds] flew or swam through the night and died when they got over there," said Hughan, the Department of Fish and Wildlife spokesman.

Deb Self, executive director of San Francisco Baykeeper, said it appears the birds were contaminated around Thursday evening, though it remains unclear what incident may have caused the contamination.

"We see [the substance] on the birds but we haven't been able to find it at the source yet," Self said. "It's not like oil where you can really see a sheen, and it's not on the shoreline. ... It could be suspended under the water."

She added that while officials have not seen such a puzzling local contamination incident in recent history, finding a spate of contaminated birds is a reminder of the vulnerability of wildlife in and around San Francisco Bay.

"It's a concern every time you've got birds that are contaminated," Self said. "It's a window into the threats the Bay and the habitats are facing all the time."

The public is advised to not touch any birds in distress and instead call local or state authorities to retrieve the animals. Online reports can be made here. The public is also encouraged to take photos of contaminated birds, which can be sent to

The International Bird Rescue is also requesting donations to help cover the cost of caring for the birds, which amounts to at least $6,000 a day, Curtis said. Donations can be made here.

About The Author

Laura Dudnick

Laura Dudnick, a Bay Area native, covers education and planning for The San Francisco Examiner. She previously worked as a senior local editor for, and as the San Mateo County bureau reporter and weekend editor for Bay City News Service.
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