St. Johns officials are warning beachgoers to keep watch for an increased presence of Portuguese man-of-war.
Man-of-War are showing up on the beaches because of persistent onshore flow for the past few days, the St. Johns County Fire Rescue said on its Facebook page Saturday.
These marine animals have been spotted both onshore and in the water. Swimmers who come in contact with their tentacles can experience a painful sting lasting two hours.
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Man-of-war are not jellyfish and commonly found on the Florida east coast from November to March, fire rescue officials said.
Swimmers and beachgoers are advised to stay away from the blue-colored, bladder-like balloon with tentacles that can reach out below the surface of the water up to 40 feet long.
Fire rescue recommends peeling or wiping off tentacles immediately after contact and apply warm water or apple vinegar on the affected areas.
Those who get an allergic reaction from contact should get help from lifeguards or call 911 if they come in contact with a man-of-war.