Miami-Dade closed beaches north of the Haulover inlet before dawn on Thursday morning after lab tests confirmed the presence of red tide in ocean waters as the toxic algae traveled from Gulf waters to the Atlantic, spreading an environmental and tourism crisis to more of Florida.
Lab tests confirmed "medium concentration" of algae linked to red tide off Haulover Park, according to a statement issued early Monday by Mayor Carlos Gimenez.
Farther south, tests off Miami Beach and Key Biscayne were "in the very-low to low range." The levels were too low to prompt beach closures south of Haulover.
Haulover Inlet is in North Miami-Dade, around 10800 Collins Ave., north of Bal Harbour.
Red tide is rare on Florida's east coast, but was confirmed in Palm Beach County on Monday after weekend beachgoers complained of symptoms linked to the toxic algae. Beaches were closed Sunday.
The finding prompted expanded testing along the Atlantic coast, including four beaches in Miami-Dade County and parts of Broward County, as well as waters about two miles offshore.
"The county received results late Wednesday indicating that elevated levels of algae linked to red tide have been detected in our area," the alert from Miami-Dade Mayor Carlos Gimenez's office said. "Although results from three sampling areas off Miami Beach and Crandon Park were reported in the very low to low range, results for samples collected off Haulover Park were reported in the medium concentration range."
Miami-Dade's beach patrol began asking people to leave Haulover on Thursday morning.
"We just came here to go to the beach, and the beach patrol person cane and said it was supposed to be bad for breathing," said Britta Toennies, a tourist from Denmark staying in Bay Harbor Islands. "So he's telling people not to be on the beach."
As a news chopper hovered overhead, Toennies and her fellow traveler, Jenny Henson, said they were going to take his advice to head for sand not covered by the county advisory.
"We were just talking about South Beach " Henson said.
It's not clear if red tide has ever appeared in the county before. Because red tide blooms regularly form in the Gulf of Mexico, scientists believe they are carried to the Atlantic coast by the Florida current, which runs farther offshore in Miami-Dade County than Palm Beach County. Coastal currents may have also carried algae south from Palm Beach County.
"You can have coastal currents that go in the opposite direction carrying it south," said Larry Brand, an algae expert at the University of Miami Rosenstiel School of Marine and Atmospheric Science. "That's how you can form islands like Miami Beach."
While amounts found at Haulover were moderate, they are high enough to trigger problems like respiratory symptoms and fish kills, he said.
How long it lasts depends on the amount of algae, winds and currents. If it's being moved by coastal currents, there's a possibility conditions worsen along beaches to the south like Crandon Park, he said.
Another concern is Biscayne Bay. If red tide gets into the bay where pollution that feeds the algae is high, it could stay longer.
"If it gets carried into Biscayne Bay, it can establish a population for a while," he said. "The bottom line is there's so many uncertainties still about the red tide. We can't predict it very well and after things happen we try to explain it."
Broward County is still waiting for results from water collected along its beaches, Environmental Planning Director Jennifer Jurado said Thursday morning.
Thursday's finding marks a significant escalation of a crisis that had until recently been confined to the West Coast. Local officials began dreading test confirmations after the algae spread to Palm Beach, Martin and St. Lucie counties, where beaches were closed this week and fish began turning up dead.
Scientists believe the blooms, which first appeared in the Gulf of Mexico off Sarasota nearly a year ago, got swept into the Gulf's Loop Current, which connects to the Florida Current and flows north along the Atlantic coast. In August and September, National Oceanographic and Atmospheric Administration satellites detected some evidence of the algae west of the remote Marquesas Islands near the Dry Tortugas, suggesting the algae could have flowed south of the Keys.
Red tide is linked to health problems, including breathing issues. The county's advisory urges "people with severe or chronic respiratory conditions to avoid red tide areas."
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