Mystery Goo On California SeaBirds Is Synthetic Oil

The mysterious gray goo that killed 170 seabirds in the San Francisco Bay Area has been identified as a non-petroleum oil substance.

California Department of Fish and Wildlife officials said Thursday that non-petroleum oils include "synthetic oils such as silicone fluids, tung oils, and wood-derivative oils such as resin/rosin oils."

"This was like a giant jigsaw puzzle, with thousands of pieces to put together," said Office of Spill Prevention and Response scientist Janna Rinderneck. "We had many possibilities of what this material could be."

Scientists at state and federal laboratories have yet to determine where the sticky gunk that looked like rubber cement came from or exactly how it got into the bay.

More than 300 birds were captured alive. Ninety-one birds remain at the International Bird Rescue Center waiting for release. So far, the Center has cleaned 323 birds and released many back into the wild. The CDFW says that the actual number of impacted birds is unknown, since many might have sank or were missed during searches.

The CDFW said the birds were first found along East Bay shorelines in mid-January covered in a substance that ranged in consistency "from an oily or gummy substance to a hard varnish." The odorless substance sapped the seabird's ability to stay warm, float or fly. The agency said secondary effects can include starvation, predation or opportunistic infections.