They ride the wind and currents, traveling in whatever direction nature intends, and every so often the mysterious blue sea creatures end up stranded on beaches throughout the west coast of North America.
This is one of those years.
By-the-wind sailors, as the gelatinous, oval-shaped critters are sometimes called, began washing ashore in Washington and Oregon more than a month ago. Since then the mass stranding has taken on the form of an alien-like invasion, with the critters showing as far south as Southern California, and as far north as British Columbia.
Naturally, they’re stirring curiosity among beachgoers, who step around them with care, poke at their jellylike bodies, and marvel at the sight of an animal that actually boasts a tall clear sail (fin) atop its body.
Scientific name: Velella velella. They're sort of like jellyfish, but not actual jellyfish. They sting to stun their prey, but are not considered harmful to humans. Mass strandings are sometimes associated with strong warm-water events, such as an El Niño.
The photo atop this post, captured this week in the Washington community of La Push, reveals the epic nature of the stranding, involving what appears to be millions of by-the-wind sailors.
The other images, captured by naturalist Jodi Frediani in Monterey, California, show what the creatures look like up-close
Michael Ellis, in a blog post for Bay Nature, writes: "The limp, soggy pieces of blue protoplasm elicit more curiosity than any other bit of flotsam along the California coast."
Frediani this week wrote on Facebook:
"I'm afraid I’ve fallen in love! With these magical, ethereal little sailing creatures. Their delicacy belies the thousands of miles they travel at the mercy of the winds and currents. Feeding on plankton just below the water’s surface, they drift and spin until eaten or stranded upon a distant shore. They have a small platform which rests on the sea and travel with the aid of a gossamer sail."
David Bader, director of education at the Aquarium of the Pacific in Long Beach, California, told CNN: "Every now and then, the currents and winds will change and these guys will, instead of being pushed out to sea, they actually wind up on the beach."
By-the-wind sailors feed mostly on plankton and fish eggs, which they catch with their tentacles.
Bay Nature offers some interesting details about the life history of Velella velella: "The reproductive polyps apparently bud off small medusae (miniature jellyfish-like structures) somewhere in the middle of the ocean. The medusae sink to depths of over 7,000 feet and grow gonads which produce sperm or eggs.
“Fertilization occurs in the dark abyss. The small young develop a float, secrete gas into it and rise slowly thousands of feet to the surface. Here they glide along feeding on animal plankton that they sting with specialized cells (located on the tentacles) called nematocysts.
"Drifting and growing, drifting and growing, Velella floats along without a care in the world. Well, not quite. There are two predators. A ocean-going sea slug and a bubble-crafting snail also cruise the ocean eating all the By-the-Wind Sailors they accidentally encounter."
Unfortunately, the creatures do not live very long on shore, and basically fade and all-but evaporate over time.
Said Bader: “A lot of people probably never knew an organism like this existed in the world. And you know the winds change, and all of a sudden they wash up on shore and we get to see what the ocean is really made of.”
More from GrindTV