FAIRFIELD (CBS SF) -- An unidentified sticky substance found on seabirds in the East Bay and Peninsula since Friday has killed about 200 birds, while more than 250 others are receiving care, California Department of Fish and Wildlife officials said Wednesday.
Of the seabirds that have died as a result of the substance, about 150 of them are at a freezing facility in Hayward and 47 were transported to the nonprofit International Bird Rescue's Fairfield facility, CDFW spokesman Andrew Hughan said.
The birds at the Hayward facility will be sent to the Fairfield center, Hughan said.
Tests have shown that the viscous substance, which is apparently not petroleum-based, breaks down the birds' feather structure, preventing them from regulating their body temperatures in the cold Bay waters, leading to hypothermia or death, according to International Bird Rescue officials.
International Bird Rescue executive director Barbara Callahan said that as of Wednesday morning, the organization has admitted 301 birds at its Fairfield center.
Forty-seven birds were dead on arrival or died while at the center. There are 254 birds being cared for, 103 of which have been cleaned with a baking soda and vinegar solution along with Dawn dishwashing liquid, Callahan said.
East Bay Regional Park District staff first found the birds on Friday at multiple sites in Alameda County, including the Crab Cove Visitor Center in Alameda, Hayward Regional Shoreline and at the San Leandro Marina, according to the nonprofit.
Over the weekend, animal rescue crews found more birds in the substance on the Peninsula coastline, according to Rebecca Dmytryk, executive director of the nonprofit Wildlife Emergency Services.
Crews searched for more birds on the Peninsula coastline between Foster City and Coyote Point on Tuesday, Dmytryk said.
Six of the dead birds have been taken to the CDFW lab in Sacramento to determine the cause of death, Hughan said.
Wednesday, rescue teams continued to look for any seabirds found contaminated by the material, state fish and wildlife officials said.
Tests have determined that the material is not toxic or poisonous, but biologists are still figuring out what the substance is, Hughan said.
The contaminated birds have been found elsewhere in the East Bay, including Oakland and Coyote Hills Regional Park in Fremont, he said.
Hughan said he expects more dead birds will be found in the coming days.
Many of the birds that were about 10 percent soiled by the substance have flown away from animal rescue teams, making the collection of contaminated birds difficult, he said.
"We're heartbroken about them but we can't rescue them all," Hughan said.
Surf scoters, buffleheads, horned grebes and common goldeneyes are among the type of birds found contaminated by the substance.
Hughan advised the public to not pick up any contaminated birds because they are fragile and dying and any disturbance may lead to further damage. Reports can be made by calling the department's tip line at (888) 334-2258.
Anyone who suspects they found a bird covered in the substance can report the sighting online.
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