The strange circular jellyfish-like creatures known as "little sails" that have been washing up in large blue lines along West Coast beaches since mid-July arrived in Humboldt later in the year than normal, according to local researchers.
Strewn across beaches from Southern California to British Columbia, the Velella velella jellyfish — also known as Velella — received nicknames such as "little sail" due to its distinctive clear, curved sail and its method of travel, according to California Department of Fish and Wildlife senior environmental scientist Vicki Frey.
"They float out in the middle of the open ocean and float with the current," she said. "They're called the 'by-the-wind-sailor' because of the type of anatomy they have, which helps to push them around. The ways the winds in the Pacific Ocean work, they end up getting blown into the west coast of North America."
While the passive sailors would regularly wash up along the shores of Humboldt County in the past, Frey said it had been several years since they last arrived on the North Coast — and that they arrived late this time around.
"It used to be that the Velella would wash up every year in the spring, when we had the northwest winds," she said. "Sometimes, it would happen in the summertime too. Personally, I don't think it's that unusual to see large quantities washing up on the beaches. We just haven't seen it in a while."
Some areas like Monterey Bay have not seen the Velella in about seven years.
Humboldt State University's Marine Laboratory Director and biology professor Brian Tissot said that the late arrival is a bit unusual, but the event is not a rare occurrence.
"The weather has been pretty weird," Tissot said. "This is one of those signs that something is going on in the ocean that's abnormal."
Like their more commonly known distant relative, the Portuguese man o' war, the Velella float on the surface of the water with their tentacles floating below the water to capture plankton prey using stinging cells called nematocysts. Though they belong to the same subphylum classification as jellyfish, Tissot said Velella are not true jellyfish, but are hybrid colonial organisms made up of several different types of polyps that serve different functions such as reproduction and defense.
"Jellyfish are generally scyphozoans," Tissot said. "Hyrdrozoans exhibit a lot of coloniality. One of them is modified to be the float to hold air, the other is modified to be tentacles. They've undergone this differential physiology to become highly specialized individuals."
Should anyone come across Velella on a beach, Tissot said they would not be harmful, but he recommended against picking them up.
"The ocean is a little bit strange," Tissot said.
Will Houston can be reached at 707-441-0504.