Napans with an urge to see jellyfish could have saved themselves a drive to the ocean or Monterey Bay Aquarium or some other far-flung location.
The Kennedy Park dock along the Napa River proved to be the perfect location for resident Renae Lamb and her 11-year-old son A.J. who discovered tiny jellyfish by the dozens last Monday morning.
“They were everywhere, all over the water,” Lamb said. “Immediately I took my dog out of the water. I didn’t want him to get stung.”
They caught a jellyfish in a clear container A. J. had brought to catch lizards. The delicate creature, a little larger than a dollar coin and pinkish, floated in these confined waters. Lamb created a video and they returned the jelly to the Napa River to rejoin its translucent brethren.
Lamb and A.J. saw the jellyfish again on Tuesday evening, though locating them amid the murky Napa River waters can be a challenge depending on lighting and other conditions.
“Kind of eerie,” Lamb said. “I was thinking maybe it’s a climate change thing, where they are suddenly showing up.”
Biologist Cathleen Cannon has had that feeling of discovery before.
“In 1993, I noticed jellyfish –which we call jellies because they are not fish – I noticed them in the Petaluma Turning Basin,” Cannon said. “That species of jellyfish had not been reported on the West Coast of North America.”
Cannon contacted researchers with the Monterey Bay Aquarium and the University of Washington Friday Harbor Laboratories.
The jellies turned out to be maeotias inexpectata that are native to the Black Sea in Russia and may have come to the Bay Area in ballast water. The creatures also go the by names maeotias marginata or Black Sea jellyfish.
“These jellies are brackish-water jellies,” Cannon said. “They are not salt water jellies.”
Nor are they jetting around like ghostly torpedoes.
“They cannot swim,” Cannon said. “Jellies are like a canoe without a paddle. You go with the flow.”
Cannon said Lamb acted wisely by taking her dog out of the river when she saw the jellies, just in case.
“By definition, a jellyfish stings,” Cannon said. “Does it hurt a human? It depends.”
She’s seen researchers place this type of jellies on their arms and suffer only a little redness. Someone with an allergic reaction might have suffered more harm, she added.
Cannon also praised Lamb for returning the jelly she and A.J. captured to the Napa River after looking at it. She hopes others will do the same.
“The jellies make terrible pets,” she said. “Leave them in the river.”
Cannon has seen the jellies in years past in the Suisun Slough of Solano County near Suisun City and in the Napa River. The Petaluma Argus Courier reported they showed up in the Petaluma River again this July.
Napa River jellies have at times caught other people’s attention. A letter-writer to the Napa Valley Register in September 1998 said he had seen them in a tide pool behind his apartment at River Park Manor along South Jefferson Street.
But how often they show up in the Napa River is unknown. Jellies evidently don’t have to be an every-year occurrence to survive in an area.
Eggs for jellies lie at the bottom of the river until conditions are right and they hatch, Cannon said. The questions are what induces the eggs to hatch and how long they can remain in the silt.
One thing is for certain – jellies have been in the Napa River this year. Whether or not their presence extends beyond this past week, Lamb has documented the event in photos and videos.
“It was a really interesting sight,” Lamb said. “I wouldn’t have believed it myself if I hadn’t seen it.”