SAN FRANCISCO, Jan. 20 (UPI) -- Wildlife officials in California say synthetic rubber or fuel additive might be to blame for the mysterious sticky goo killing and sickening birds in the San Francisco Bay.
At least 80 birds have been found dead and some 300 injured, all of which were covered in the sticky, gray-colored goo.
"They are covered in this goo, and it is so weird because it really looks like rubber cement," Barbara Callahan, the interim executive director of International Bird Rescue, an aquatic bird rescue center in Fairfield, Calif., told the San Francisco Gate. "It's kind of gray. It's hard to get off in the wash. It is sticky, but it doesn't want to come off the feathers."
The odorless substance isn't poisoning the birds, but is instead causing them to lose body heat. It coats the birds' down feathers, breaking down their insulating waterproof seal.
"We know it's not a public health or safety risk," Andrew Hughan, the spokesman for the Department of Fish and Wildlife, told the Gate. "It killed the birds because they froze to death. It sapped all the heat out of them. They were not poisoned. They died because of a loss of body heat."
Some officials believe the substance could be synthetic rubber or polyisobutylene, a fuel additive. Lab tests on the substance are expected to provide a clearer picture of what is killing the birds.
"To me, it's extremely likely not an organic product, like vegetable or fish oil," she said. "It's not an algal bloom or anything like that.
"It's highly likely it's a man-made product, which means we've had a breach in a pipeline or someone intentionally fouled the East Bay."