Jellyfish-like creatures have been washing up on the west coast shores of North America all summer.

It started in Washington and Oregon, billions of small creatures began washing up on the beaches. They could easily be mistaken for jellyfish, but they are actually called “by-the-wind sailors” or “Velella velella.”

“The scientific name is Velella velella,” said David Bader, director of education at the Aquarium of the Pacific in Long Beach, California. “They’re jelly-like creatures, but they’re not exactly jellyfish.”

The creature’s body is described as deep blue with jellyfish-like top and stinging tentacles that hang down. It has a fin atop its body that catches the wind in order to help it move from place to place.

“Out at sea, they look like bubbles on the surface of the ocean until you get up on them,” said Julie Bursek of NOAA’s Channel Islands National Marine Sanctuary.

The creatures are carnivorous, feeding primarily on plankton and fish eggs. They also pack a sting that paralyzes their prey. It’s to be noted, however, that humans don’t need to be afraid of the Velella velella creatures. Scientists report that their sting isn’t very potent on humans. It’s nothing like the sting of a jellyfish.

“That sting is not very potent. It’s nothing that could actually get through my skin,” David Bader said while he lifted a handful of the creatures.

Not only are the creatures not all that frightening in the sea, but they become less-so on land. Velella velella do not survive very long on shore. Slowly, their blue color will fade until they’re almost completely clear.

When the creatures have expired the clear portion of their body will lose color quickly, with the tough fin being the only part that remains.

What started as a reported view here or there in a couple of states has become a mass scene of sea-creature death. Beaches full of Velella velella are being reported all along the west coast from southern California to British Columbia.

“The numbers, if you extrapolate, are awe-inspiring,” said Kevin Raskoff, a professor of Biology at Monterey Peninsula College. “With some of my students we counted more than a thousand per meter.”

There are several possibilities for the odd occurrence. It could have something to do with ocean currents carrying groups of the jellyfish-like creatures far from their usual areas; or it could have something to do with their prey being thinned out by over-fishing.

Experts don’t know the reason behind the sudden appearance of the creatures, but they are looking into it.

[ Images courtesy of Sky News, ReBloggy, and The Dancing Rest ]