Local residents recreating on Stumpy Meadows shared this photo of the jellyfish taken from a paddle board. The jellyfish reportedly are more likely to be seen in the middle of the lake rather than near the shore or boat ramp. Photo courtesy of Casey Richard Neet
Local residents recreating on Stumpy Meadows shared this photo of the jellyfish taken from a paddle board. The jellyfish reportedly are more likely to be seen in the middle of the lake rather than near the shore or boat ramp. Photo courtesy of Casey Richard Neet
Recent visitors to Stumpy Meadows Reservoir near Georgetown have spotted an unexpected new resident in the cool waters — small, penny-sized jellyfish.
The freshwater jellyfish (Craspedacusta sowerbyi) are a non-indigenous aquatic life form originally from the Yangtze River valley in China, but have become widespread in the U.S. since first being recorded in the country in 1880, according to information from the U.S. Geological Survey. Maps tracking the spread of the small creature — also known as a hydromedusa — show that it has grown exceedingly prevalent in East Coast waterways and has started to spread to the Bay Area, Central Valley and Sierra Nevada in California. It is believed the creature was originally accidentally introduced to the U.S. through ornamental aquatic plants and fish and is currently spread through boating and other recreational water activities.
Sightings of the jellyfish have been reported occasionally in other waters of the Eldorado National Forest over the years, though not all have been verified, according to Maura Santora, aquatic biologist for the U.S. Forest Service who works in the ENF.Â
"This year, only Stumpy Meadows Reservoir has been reported and verified on the forest," Santora states in an email. "This is my first time hearing about them in Stumpy Meadows Reservoir during my nine years on the Eldorado National Forest."
The jellyfish, called "peach blossom fish" in Chinese, are minuscule, measuring in at 5-25 millimeters in diameter (a U.S. penny measures in at 19.05 mm). The habitat for the jellyfish is slow or still water, and they are translucent with a whitish or greenish tinge. Tracking their movement through waterways can be difficult, as the jellyfish have multiple forms other than their free-floating bell look, and their appearance is sporadic and unpredictable from year to year, Santora states.
Visitors to the reservoir looking to see if it truly is the best spot to swim in the Sierra, like a recent SF Gate article claims, need not worry about stings. Though the freshwater jellyfish does have stinging cells to feed on tiny fish and macroinvertebrates, they do not penetrate human skin and are not considered harmful to humans through contact in the water.Â
Eldorado National Forest officials note the ecological impact from the presence of the jellyfish is unknown. The USGS cites past studies that have found hydromedusa fed on zooplankton and copepods and that crayfish may be its only predator.
In the hopes of stemming the spread of non-native species, visitors to Stumpy Meadows and any other body of water should practice clean, drain and dry procedures.
Jelly beans, jelly rolls, jalapeño jelly on cornbread! Anything but another invasive species from our friends I’ll bet. I sure hope manatees don’t pop up in Buck Island or worse, Webber pond!
All kidding aside, these jellyfish, which don’t foul pipelines and engines, or crowd out native species, probably hitched a ride on the feet of waterfowl.
I've seen these in the Consumnes River too! I wonder if they'll spend the time and resources like Tahoe Lake to stop the invasive species; Or does this just apply to mud snails and not jelly fish!
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Jelly beans, jelly rolls, jalapeño jelly on cornbread! Anything but another invasive species from our friends I’ll bet. I sure hope manatees don’t pop up in Buck Island or worse, Webber pond!
All kidding aside, these jellyfish, which don’t foul pipelines and engines, or crowd out native species, probably hitched a ride on the feet of waterfowl.
I'm guessing that they came from a Chinese bat that flew across the pacific and dropped them here.
I've seen these in the Consumnes River too! I wonder if they'll spend the time and resources like Tahoe Lake to stop the invasive species; Or does this just apply to mud snails and not jelly fish!
Nice story. I have seen these little guys in lakes all over the Eldorado National Forest including Silver Lake and Wrights Lake.
Black Rock Lake in Mokelumne Wilderness.
That is so cool...
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PLEASE TURN OFF YOUR CAPS LOCK.
Don't Threaten. Threats of harming another person will not be tolerated.
Be Truthful. Don't knowingly lie about anyone or anything.
Be Nice. No racism, sexism or any sort of -ism that is degrading to another person.
Be Proactive. Use the 'Report' link on each comment to let us know of abusive posts.
Share with Us. We'd love to hear eyewitness accounts, the history behind an article.