A recent visit to Coyote Hills Regional Park seemed to perfectly encapsulate the two-faced nature of the San Francisco Bay. At first glance it was peaceful, serene, and utterly breathtaking, yet upon peeling back a layer or two I uncovered a dirty, polluted mess. In January 2015, dozens of birds washed up in the East Bay Area covered in what was then described as a "mystery gunk," a viscous, grey substance that impaired their abilities to remain waterproof and regulate internal temperatures. At the time, wildlife officials were perplexed, as the substance was neither petroleum nor fish or vegetable oil. After running a series of tests, the California Office of Spill Prevention and Response determined the substance was a type of synthetic oil, similar to the kind used in cars to replace petroleum-based motor oil. Although the source of the spill remains unknown, the majority of the birds affected have made a full recovery, and have since been returned to their natural habitat.