Health officials are warning people not to swim at North Shores Beach after a strain of bacteria known to cause infections was detected in the water.
The Florida Department of Health in Miami-Dade County issued a swimming advisory for the waterfront area at 73rd Street and Collins Avenue in Miami Beach after a two samples showed levels of enterococci that exceeded state and federal health standards.
Officials say entering the water could put swimmers at an increased risk for illness.
Yet swimmers at the beach said they weren't aware an advisory had been issued.
"I didn't even know there was an advisory, but I'm not surprised," said Miami Beach resident Judy Carson.
Others didn't seem to mind the warning.
"I feel great. Couldn't have had a better experience in the water," said Dan San George, who was visiting from New York.
He and other tourists said they were just glad for the relief from the cold.
"It's nice, it's warm, it's not freezing like up north," said Ray Da Costa from Massechusetts.
The rest of Miami-Dade County's public beaches did not show dangerous levels of the bacteria, which can indicate fecal pollution in the water.
Health officials have their eye on several potential causes for the outbreak, including storm water run off, sewage and even pets.