An unknown, viscous substance has been found in dozens of seabirds, including 29 dead ones, on the San Francisco Bay's eastern shores, rescuers and state wildlife officials said Saturday.
The mysterious gunk came to officials' attention late Friday when some birds were seen looking distressed in the water and stranded on land in Alameda, the Hayward shoreline and the San Leandro marina, said Barbara Callahan, interim director of International Bird Rescue.
"It's very mysterious," said Julie Skoglund, who works at the rescue. "It appears to be localized to one area, so the birds seem to be affected in one area, coming in in one area."
In all, 179 seabirds were taken to the rescue center, and 29 dead ones were recovered in the field.
Preliminary laboratory tests found the thick substance, which is clear to pale gray in color, is not petroleum or toxic, said California Department of Fish and Wildlife spokesman Andrew Hughan. It doesn't smell, isn't fish or vegetable oil-based, and can't be removed by soap.
"We don't know what it is,'' Hughan said.
The substance damages the birds' feathers and ability to remain waterproof, which can lead to hypothermia in the bay's cold water, Callahan said.
The Coast Guard flew over the area and didn't see a spill or other indication of where the substance came from.
The International Bird Rescue center near Fairfield is washing, feeding, and caring for the seabirds brought to them covered with the substance.
"They’re coming in anywhere from lightly contaminated to heavily contaminated, and they just completely lost their water proofing," Skoglund said. "Many of them are very wet and just hypothermic and very contaminated."
The birds infected contaminated include buffleheads, seaducks, and grebes.
Further lab tests of the substance will begin Tuesday after the holiday weekend, and a necropsy will be performed on the dead birds, Hughan said.
It is estimated there will be at least 200 birds sickened by this mysterious substance. According to Wildlife Emergency Rescue, state officials said it is not toxic.