This summer, beachgoers across Rhode Island noticed something a little different in the water: tiny gelatinous blobs – smaller than a marble – floating in the waves and washing up onshore.
But these squishy spheres were not jellyfish. Instead, they’re a different sea creature, called salps.
“They’re a zooplankton,” according to Sean Colin, a professor of Marine Biology and Environmental Science at Roger Williams University. “They float in the water. And they’re gelatinous… they are actually completely unrelated to jellies — much more closely related to us than to jellies.”
During their development, salps have a notocord, which is related to the human spinal cord. And unlike some jellyfish, salps do not sting and are harmless to touch.
Salps are a type of tunicate, a group of marine invertebrates that include sea squirts, according to the Smithsonian Museum of Natural History.
Beachgoers may also find salps connected in chains. Salps can reproduce asexually, so chains are generally composed of identical females, according to Colin. Salps in chains can swim in tandem, and some chains can be found creating spiral patterns in the water column.
Salps usually live in the open water, but can hitch a ride on our ocean currents, though, and end up closer to the coast.
“They like to be in water that is crystal blue,” Colin said. “So they’re usually found offshore on the other side of Block Island, out in the Gulf Stream.”
Currents can sweep in all kinds of flora and fauna. The Rhode Island Department of Environmental Management said that August’s Hurricane Erin and strong southerly winds might be the cause of this summer’s salp visits.
As filter-feeders, salps eat microscopic phytoplankton.
“They don’t do well in shore, because there’s just too much stuff in the water,” Colin said. “If there’s too much stuff in it, their filters get clogged too fast.”
At East Matunuck State Beach in South Kingstown, R.I., on a recent beach day, Hannah Zweig swam among the salps. Zweig, who had driven down from Providence, found them a little strange.
“They’re just kind of squishy,” Zweig said, “I’m not sure I’m a fan.”
She and others who think the squishy creatures a nuisance may be comforted by the fact their visit to New England beaches will be short — often just a week or two. Many Rhode Island beaches appeared to be salp-free at the end of August.
The Public’s Radio’s Jeremy Bernfeld contributed to this story.
