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Blue blob colony creatures invade California beaches

Translucent round animals, blue at bottom and yellow on top on sand.
Blue blob jelly-like creatures washed ashore at Crystal Cove State Park in Laguna Beach, California, on Saturday, April 8, 2023. Velella velella – commonly known as by-the-wind sailors – are colony creatures made up of thousands of tiny animals called zooids. While harmless to humans, by-the-wind sailors do sting. Image via California Department of Parks and Recreation.

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Blue blob creatures invade California beaches

Strange creatures from another realm are invading the beaches of Southern California. Extraterrestrials? No. The bluish blobs washing up by the millions are called by-the-wind sailors (Velella velella), which hail from deep, warm ocean waters. Each by-the-wind sailor is really a colony of creatures that spends its life drifting with the breeze.

The masses of blue, jelly-like floaters were first reported by Nona the Naturalist with Dana Wharf Whale Watching on Saturday (April 8, 2023) during an observing cruise off the Southern California coast.

Nona described the encounter for her viewers:

The water is also full of hundreds of these organisms. These are called by-the-wind sailors. They feed on alga and zooplankton in the water, and organisms like our ocean sunfish love to eat these.

What are these things?!

By-the-wind sailors are technically not true jellyfish. Nor are they individual animals. Instead, the approximately 4 inches (10 cm) oblong masses are colonial hydroids.

Marine biologists at San José State University gave a good description of their lifestyle:

In these communal groupings, individual polyps are connected and share resources through a hydrocaulus [a hollow stem inside individual polyps]. Colonial hydriods have specialized individuals, or zooids, that exist to fulfill a specific need in the colony. For example, the most common type of zooid is a gastrozooid, which provides the colony with food. Gonozooids are used in reproduction, while in some species nematocyst-filled cells called cnidocytes aid in defense.

Leave the blue blobs alone

By-the-wind sailors are similar in appearance and composition to the deadly Portuguese man o’ war, but the two are unrelated.

And – unlike the Portuguese man o’ war – the by-the-wind sailor has never been known to kill people.

Both are colony creatures made up of zooids, but Jellywatch.org says they’re fundamentally different:

Although they [by-the-wind sailors] are blue-colored hydrozoans and float partly above the water like the Portuguese man o’ war (Physalia), they are not especially closely related to it or other siphonophores. Even recent literature called them siphonophores, but the nearest Cnidarian relatives are the Capitate hydroids.

They sting, but aren’t harmful to humans

While by-the-wind sailors can sting their microscopic prey, they are not considered harmful to humans. And they should be handled with caution. The NOAA recommends avoiding all jellies when visiting the shore.

Plus be aware that – when the sailors wash ashore – their remains can be unpleasant for those strolling the strand, according to the University of Washington:

When they wash ashore, these jellies quickly dry to the consistency of potato chips. During a mass stranding it’s like walking on a crunchy carpet.

Climate change is good for jellies

Mass strandings of by-the-wind sailors can be … massive!

At one point during strandings that occurred from 2015 to 2019, dead Velella covered a 620-mile (1,000-km) continuous stretch of West Coast beaches, the University of Washington (UW) reported.

That was the second of two periods of boom years for by-the-wind sailors, which UW researchers identified by analyzing 20 years of citizen reports. By looking over the data, they found the massive strandings corresponded to years of warmer weather.

The second period corresponds with the timing of the long-lasting marine heat wave known as the blob, also to blame for the largest seabird die-off of common murres, as well as mass die-offs of cassin’s auklets, sea lions and baleen whales.

Warmer ocean temperatures result in larger populations of by-the-wind sailors and other jellies. Populations can reach into the trillions. The spring winds then push the floating hydroids onto shore.

According to Julia Parrish, a professor at the UW School of Aquatic and Fishery Sciences, by-the-wind sailor blooms like the one happening now are a marker of climate change:

Our data really do suggest that in a warming world, we’re going to have more of these organisms, that is, the ecosystem itself is tipping in the direction of these jellies because they win in warmer conditions. A changing climate creates new winners and losers in every ecosystem. What’s scary is that we’re actually documenting that change.

Bottom line: Blue blob colony creatures are washing up by the millions on California beaches.

Read more: Big seaweed bloom headed to Florida and Caribbean

Posted 
April 13, 2023
 in 
Earth

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