Thousands, possibly millions, of hockey puck-sized creatures washed up along the shoreline near San Francisco Bay this week, but an expert says don't be alarmed.
Strong winds probably drew the colony of creatures, known as Velella velella, to Ocean Beach in San Francisco, where they dried out and died, said Rich Mooi, curator of invertebrate zoology and geology at the California Academy of Sciences. The creatures, he said, are not dying off.
They are known to bloom and float to shores along the northern continents around April, May and early June. The latest bloom, however, is unusual because it happened later than expected.
"It's a little bit out of whack," Mooi said.
Although Mooi doesn't know why the silver and purple creatures bloomed late, he said the event doesn't indicate something is wrong with the ocean.
In any event, dozens of spectators took to Twitter this week and posted photos of the creatures along Central and Northern California shores.
The creatures were also spotted along Monterey Bay.
Equipped with a projecting sail, the jellyfish-like creatures work as a single organism as they move along the ocean's surface in search of food and to reproduce.