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Officials Test Gray Goo Connected with 125 Bird Deaths

San Francisco Bay Area officials have begun laboratory tests and necropsies on dead seabirds found coated with a mysterious substance that looks and feels like dirty rubber cement. More than 125 dead birds have been found along the bay's shorelines, said Andrew Hughan, spokesman for the California Department of Fish and Wildlife. "We expect that number to go up," he said. The goo covers their feathers, and the birds lose their ability to insulate themselves. They eventually freeze to death. Hughan said the wildlife agency's preliminary tests show the gray gunk is not a petroleum-based substance or an organic product like vegetable or fish oil. But final results might not come until later this week.

"You can't rush science," Hughan said. "It will be what it is, when it is." Officials say the substance is not a public health or safety risk to humans. They are investigating whether it could be polyisobutylene, a sticky, odorless, largely colorless material that killed thousands of seabirds in the United Kingdom in 2013. Even when the pollutant is identified, it could be longer before officials pinpoint its source.

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— The Associated Press