Toxic green algae has taken over the beach in Martin County, Florida.
Yellow and purple flags fly along the coast and signs are posted at public entrances, warning people not to make contact with the water.
Lifeguards are inspecting the beach and testing the water’s toxicity.
The ocean’s health risk has put a damper on the holiday weekend– the beach is nearly empty.
Some residents in the area say they won’t be getting into the water until they’re sure it’s safe.
“The seaweed is mixed with the blue-green algae so I will not be getting wet today,” Jenson Beach resident Patty Knott said. “No swimming.”