The first birds showed up on Jan. 16, and from that point on, over 100 dead seabirds were found along the shoreline on the Bay primarily in San Leandro and Hayward. The birds were covered in a strange-looking substance resembling dirty rubber cement. Andrew Hughan, spokesman for the California Department of Fish and Wildlife said that by Jan. 22, about 200 dead birds had been found.
Luckily almost 500 other seabirds were rescued and taken to the International Bird Rescue Center in Fairfield. There, workers loosened the feathers using baking soda and vinegar before washing them off with dish soap. Hughan explained that the mystery goo stuck on the feathers, making the birds unable to properly insulate their bodies against the cold. They died of hypothermia.
Last week, 80 seabirds, including surf scoters, buffleheads, and horned grebes, were released back into the environment. On Wednesday, an additional 20 to 30 rehabilitated birds were released at Middle Harbour Shoreline Park by The International Bird Rescue. “This has been incredibly difficult and taken a lot of time per bird,” says Rebecca Dmytryk of Wildlife Emergency Services, one of the volunteer groups taking part.
Odorless and colorless, the slime has not been identified, and wildlife officials don’t know where it came from either. Initial field tests came back negative for petroleum. The industrial chemical polyisobutylene, used in making synthetic rubber was also investigated. This substance was responsible for killing 4,000 seabirds off the Southwest coast of England in 2013 after it spilled from a cargo ship.
Polyisobutylene was ruled out on Wednesday Jan. 21, so it is not the culprit. “That’s really good news. It eliminates one possibility, but there are still lots of other things it could be,” Hughan said. “This is a full-bore effort. The lab has got its whole staff going. They are testing for everything.”
Hughan brought up the mass die-off of seabirds up and down the coast of California in 2007. At that time, it was finally determined the die-offs were attributed to a red-tide algae bloom in the Monterey Bay. But the culprit in that case was not the algae itself, but a sticky “sea foam.” It looked very much like “dirty Kool-Whip” and had the same consistency said Dr. Raphael Kudela, one of the authors of a study published in the journal PLoS One.
What scientists learned about the foam is interesting, because while the algae itself was not toxic, the residue left from the dying algae, the sea foam, had a detergent-like quality. The foam matted down the bird’s feathers, stopping their ability to insulate themselves. It is the same as what has happened this time. It will be interesting to find out what wildlife officials decide.