By Barbara Liston
ORLANDO Fla. (Reuters) - Jellyfish stung at least 400 Florida beachgoers over the weekend, prompting lifeguards to raise purple flags warning of hazardous marine life off the state's east coast, authorities said on Monday.
Authorities said the jellyfish swarm arrived on Friday and has remained concentrated around New Smyrna Beach, on the Atlantic coast in the north-central part of the state.
"It could be thousands. It's hard to see them in the water right now. All you can see are the ones on shore," said Volusia County Beach Safety Captain Tammy Marris.
No one was seriously injured, Marris said. Lifeguards treated most of the victims with a splash of vinegar, which quickly halts the burning pain of the sting.
Jellyfish stings can be dangerous or fatal in rare cases in which the victim is severely allergic to the venom.
Marris said the size of the swarm and number of people stung are not unusual, adding that it is hard for beachgoers to predict when the jellyfish will wash towards shore.
"They're at the mercy of the wind and the current," she said.
Jellyfish are gelatinous, umbrella-shaped animals with long, trailing tentacles that release venomous stingers on contact with skin or prey. They can appear in various colors but typically surface with a translucent milky color on central Florida beaches.
Local lifeguards stock vinegar, which can deactivate the stingers, as can salt water. Fresh or tap water can reactivate them. Stung beachgoers can also find relief by submerging their wounds in hot water.
A storm front on Monday churned up the surf, which was calm over the weekend, but so far has not washed the jellyfish out to sea, officials said.
(Reporting by Barbara Liston; Editing by Letitia Stein and Jim Loney)