Velella Velella, a small blue jellyfish-like creature, washing onshore at Baker Beach in San Francisco on April 28, 2026.
SAN FRANCISCO - If you've been to Baker Beach in San Francisco this week, you've probably seen droves of blue jellyfish-like creatures covering the shore.
Despite their deceiving appearance, these flat, oval-shaped animals are not technically jellyfish, but Velella Velella, or by-the-wind-sailors. The species is, however, related to jellyfish, along with sea anemones, corals, and hydroids, according to the National Park Service.
The creatures live on the surface of the water and wash up on beaches in the spring and early summer months. They are blue and purple in color and have blue tentacles that contain stinging cells, according to the park service.
What is a Velella Velella?
What we know:
The body of a Velella Velella has a "sail," which is triangular and 2-inches high, hence the "by-the-wind-sailor" name. The creatures can't exactly navigate the water using their sail, but they move with help from the wind – making them different than jellyfish, which drift with ocean currents.
The California Department of Fish and Wildlife notes the species cannot control its direction, only moving by "sail."
When winds shift, the blue creatures are drawn to the coast.
"When the prevailing winds shift, such as during a storm, the Velella are driven towards the coast, where they often are stranded on beaches in great numbers," the National Park Service says. "As the Velella dries out on the beach, it becomes brittle and transparent, looking like a cellophane candy wrapper."
Baker Beach, San Francisco on April 28, 2026
Are Velella Velella dangerous to humans?
Why you should care:
The small creatures are not dangerous to humans and have very few predators because of their stinging cells. The known predators include nudibranchs (sea slugs) in the genus Glaucus and purple snails in the genus Janthina, according to the National Park Service.
The small blue sea creatures resemble plastic when they wash up on shore, due to the translucent fading that happens when they die on the shore.
What draws Velella Velella to ocean shores?
"After they leave the water and die on the shore, their bright blue bodies fade translucent, and their texture becomes just like a plastic bag," Southern California's Morro Bay National Estuary Program says.
The nonprofit says warmer ocean temperatures and storms can drive the creatures to be stranded on shore.
The Source: National Park Service, California Department of Fish and Wildlife and the Morro Bay National Estuary Program.