Blue jellyfish relatives swarm California beaches amid climate change

California's beaches were recently adorned with thousands of unique creatures that resemble blue jellyfish, commonly referred to as "sailors." A biologist has clarified that these creatures are distant relatives of the well-known jellyfish.

This peculiar phenomenon was observed on Monday, March 26, at Rodeo Beach in Marin County, California. The blue, jelly-like organisms are a type of cnidarian known as Velella velella.

In English, these creatures are colloquially known as By-The-Wind Sailors, a name derived from their sail-like appearance and their ability to drift with ocean currents.

Blue jellyfish commonly wash up on shores during spring and early summer. This is typically due to the strong winds that occur around California during these seasons, recently exacerbated by gales and storms.

A video posted on the Harte Research Institute for Gulf of Mexico Studies' Facebook page features a local biologist explaining what Velella velella are. The researcher assures that they are not harmful to humans, although their tentacles might irritate those with particularly sensitive skin.

The beaching of so many individuals may be associated with rising sea temperatures. Scientists link the presence of velellas to climate change and the El Niño weather phenomenon, which results in higher-than-average water surface temperatures in the equatorial zone.

The frequency of these cnidarians appearing on beaches is expected to increase annually due to climate change.