What Are Those Black Clumps on the Beach?

tar ball natural oil seeps Santa Monica Bay Dockweiler Beach

"I was walking along Dockweiler Beach from Marina del Rey towards El Segundo, and I couldn't help but notice black sticky roundish clumps all along the beach in the sand where the water breaks along the shore. Are these oil deposits? I stepped on a few and they stuck to my feet and I was wondering what they were? Thanks for your help.” 

As we often receive variants of this question, our Science & Policy team prepared an answer:

Natural oil seeps are present in the Santa Monica Bay off the coast of Redondo Beach and Manhattan Beach. They are a natural geological occurrence and are not caused by any human activity. On average, about 10 barrels (420 gallons) of oil from the seeps reach the sea surface daily in Santa Monica Bay. Surface oil generally drifts northward, towards the shore, reaching the beaches from Redondo Beach to Malibu in a few days. Tar on Santa Monica Bay beaches also comes from natural seeps in the Santa Barbara Channel. Geologic activity, like earthquakes, can affect the flow of natural oil seeps.”

As for removing beach tar from the bottoms of your feet, many of us beachgoers—especially those of us who’ve spent time on Santa Barbara’s beaches, where tar is even more prevalent—recommend using either baby or olive oil.

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