Long weekend visitors to Tofino, B.C., might have thought they were witnessing something out of science fiction, with hundreds of tiny, blue, jellyfish-like creatures covering the beaches.

But what was initially thought of as a rare sighting of Velella velella is likely the new normal.

Mayor Josie Osborne says spring-time strandings of Velella velella on Tofino's beaches has grown over the last decade due to warming ocean temperatures.

"We've been seeing hundred of thousands of tiny baby Velella velellas," said Osborne. "In the past few days, we've been seeing much larger individuals, more fully formed adults if you will."

Warm water conditions coupled with the right amount of plankton created the current population boom, according to Osborne, who is also a marine biologist.

The creatures, also known as "by-the-wind sailors" because of the sails on their backs, are small carnivorous animals related to jellyfish that live on the surface of the water, normally hundreds of miles offshore.

They can't swim, so their movements are dictated by wind. Tofino had wind gusts up to 56 km/h over the weekend.

"It's a one-way trip that doesn't end well," said Osborne. "That's the result of these sustained westerlies. They just have no way of getting back in the ocean."

Careful where you step. Thousands of Velellas washed up on Tofino's shores Easter weekend. Their sting won't harm humans or four-legged friends (Emily Brass/CBC)

Velellas don't survive long once they hit the beach. The body dissolves, and what's left behind are, depending on the size of the influx, hundreds of thousands of little plastic-looking dried up sails.

"We've had visitors come to the visitor centre and say, 'oh my God! There's plastic garbage all over the beach," said Osborne.

"But it's not. It's just the sail ... and they take a little longer to rot away."

Four-legged friends can be attracted to the smell of the rotting creatures, and, to the concern of their owners, often can't resist helping themselves to a seaside snack.

And while Velellas can sting — they are closely related to Portuguese-man-of-war that are notorious stingers — Osborne said the small amount of neurotoxin that's released might give a dog a stomach ache but won't cause any harm.

And if humans touch them?

"If you rubbed them all over your face, you might feel something," said Osborne. "I wouldn't recommend that."

Thousands of the creatures washed up in Tofino in August 2014, turning the shores into a sea of blue. In 2016, thousands more were spotted on the shores of Haida Gwaii.

Despite the untold number of fatalities among the creatures, Osborne said, there is little cause for concern.

"It is a natural occurrence — all about winds and currents!"