MOSS LANDING >> A blue jellyfish-like creature is washing up on West Coast beaches, including the sandy shores lining the Monterey Bay.
But unlike jellyfish, the rubbery Velella velella (vuh-lell-uh vuh-lell-uh) live on the surface of the water. Also called by-the-wind sailors, they have a triangular ridge running across them that acts like a sail. They ride the currents, using their fringe of tiny tentacles down below to feed on plankton and to reproduce small jellies the size of mustard seeds.
But when the winds change every three to seven years, it’s a death sentence for billions.
“When we get these winds driving them from their offshore habitat, and some of them get washed up on beaches, it’s like a sailboat race,” said Steve Haddock, senior scientist with the Monterey Bay Aquarium Research Institute.
For the past month, beachgoers have been seeing the azure hydrozoans from Washington to Ventura. Last year, their distribution stretched from Alaska to Mexico, Haddock said.
Velella live on the wide open ocean in clusters of a million and counting. Whereas jellyfish have rocks and other features of the seascape to latch onto, velella have nothing but the surface of the water. They float upside down from our perspective — their “sky” is the ocean.
The harsh sun can beat down on velella. As protection, their brilliant blue color functions essentially as sunscreen, Haddock said.
When velella become beached and waves fail to pull them back into the water, they quickly dry out and turn clear. The palm-sized free-floating polyps also start to smell, drawing flies that swarm their light plastic-like bodies.
“The beach has just been littered with them,” said Robert Gain of Castroville while walking on the beach in Moss Landing. “I don’t like stepping on them when they’re fresh and slippery.”
Finding velella carpeting the coastline often occurs with annually spring winds, but cyclical massive die-offs can be difficult to predict. And if warmer water comes near shore, velella might follow.
“Their life cycle leads to these boom and bust periods,” Haddock said. “We can get them coming through the summer like last year. It’s just a combination of prevailing winds and currents.”
The Monterey Bay Aquarium Research Institute has the website www.jellywatch.org where people can help scientists with research by documenting their velella sightings.
“There’s not a lot of scientific studies on velella, sea nettles or any other jellies,” Haddock said. “People expect jellyfish to be increasingly important, but without records, casual observations are pretty much the main data set.”
