California beaches have seen some tragic events this year, with dead sea lions, dolphins, seagulls, pelicans, and even a minke whale washing ashore from San Diego to Santa Barbara. Recently, however, beachgoers have witnessed a beautiful marine life phenomenon: hundreds of thousands of Velella velella, also known as by-the-wind sailors, sea rafts, purple sails, or little sails, have washed up along the California coast.
These small creatures resemble oval mini-sailboats and can grow up to 4 inches long. Their gelatinous bases range in color from vibrant blue to deep purple, with a transparent triangular “sail” on top, which allows them to be carried by the wind across the surface of the sea, their usual habitat, and, with strong enough winds, onto the shores.
Though it may be a new sight for some, the appearance of these creatures on the beach is an expected seasonal event. During the winter months, winds along the U.S. west coast blow from the south, but in April, the prevailing wind direction shifts, bringing large numbers of Velella to the shores.
These creatures are related to sea anemones, corals, hydroids, and jellyfish. However, unlike jellyfish, they cannot swim or control their direction. They are also often confused with the Portuguese man o’ war due to their bright blue color, but they are not as dangerous to humans. While both use tentacles to capture prey, the stinging cells (nematocysts) of Velella are harmless to humans, though they can cause irritation if touched.
Once they wash ashore, these creatures only remain for a few hours before drying out and decomposing. During this process, their vivid hues fade, leaving behind plastic-like, crunchy remnants.
Recent studies have suggested a possible link between the mass strandings of Velella and rising ocean temperatures. While such events have been recorded for many years, some research suggests a relationship between the strandings and sea surface temperatures from the previous winter.
However, some view the appearance of Velella as a warning sign of climate change, while others, like photographer Emily Scher, consider it a positive indication of the health of marine life.
