Thousands of Blue Blobs Wash Up in California, Signaling Spring

Plenty of random stuff washes up on beaches, ranging from rubber ducks to a giant eyeball. Now small blue creatures resembling melted plastic are appearing on Californian beaches—again.

Smithsonian reports that beachgoers in the Bay Area have been spotting flocks of the blue, jelly-like animals by the thousands. They’re called Velella velella, or “by-the-wind sailors,” because they have a structure that resembles a sail, letting them catch breezes and travel on ocean currents. Their sails are even angled differently depending on where they are in the world due to regional wind currents. Consequently, those in the Northern Hemisphere are largely “left-handed,” while those in the Southern Hemisphere are mostly “right-handed.” According to the Pacific Beach Coalition, these creatures resemble jellyfish but are actually a different, related species. The blobs are free-floating hydrozoans, which bob on the water’s surface. Unlike jellyfish, which can swim, by-the-wind sailors can’t move on their own.   

The animals may look mysterious, but they’ve shown up on California’s shoreline before and will continue to do so. Raphael Kudela, a marine scientist, tells Smithsonian that by-the-wind sailors typically wash up on Northern Californian beaches during the spring or early summer because of upwelling. This occurs when strong winds shift deeper, colder, nutrient-rich water to the surface. As a result, large groups of Velella are caught by the currents and pushed ashore. This can make the tiny creatures lose their pigmentation and become transparent. A 2021 study suggests that the increased Velella strandings might be connected to rising ocean temperatures, though more research is needed on the subject.

Their numbers may seem intimidating, but the animals are generally harmless. However, Carolyn Belak, an aquatic ecologist, tells SFGATE that the Velella’s stingers can irritate the skin, so it’s best not to touch them.

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