Reports over the weekend of beachgoers on Florida's Atlantic coast complaining of coughing and wheezing means Red Tide toxic algae has reached a rare peak.
The bloom has now touched all three of the state's coasts, according to the Florida Fish and Wildlife Conservation Commission. This appears to be only the second time that has happened since the state began officially tracking the blooms. The last time was nearly 20 years ago.
This one began along the Southwest Florida coast last November, intensified over the summer, then reached both the Pinellas and Panhandle beaches last month. Now it has been carried by currents through the Keys and swept up along the state's east coast as well.
"We've detected low to medium concentrations of naturally-occurring Red Tide in water samples taken Sunday … off the coast of Palm Beach County," wildlife commission spokeswoman Susan Neel said in a written statement late Monday.
Red Tide blooms are subject to wind and ocean currents that push them around. For instance, while Pinellas' popular beaches were mostly free of the foul odors and fish kills over the weekend, the large bloom persists just offshore, Pinellas County environmental management director Kelli Hammer Levy said.
An easterly wind has kept it away from land temporarily, but if the wind shifts to the west, that can change.
Similarly, the currents in the Gulf of Mexico shift Red Tide blooms around, even pushing a bloom to the east coast, according to Robert Weisberg, a physical oceanography professor at the University of South Florida's College of Marine Sciences.
In this case, what's pushing it is the Gulf Stream, which originates in the gulf and flows into the Atlantic at the southern tip of Florida, accelerating along the eastern coastline of the U.S., ultimately helping to keep Europe warm.
"The Gulf Stream goes very close to the beaches of Palm Beach County before it bends to the north-northwest," Weisberg explained.
On Saturday, beachgoers in Palm Beach County complained of respiratory problems as well as skin and eye irritations, prompting county officials to close several beaches. The symptoms are identical to the ones experienced by residents on the gulf coast who have been dealing with the microscopic marauder all summer long, along with fish kills and the deaths of dolphins, manatees and sea turtles.
Although an unusual event, this is not the first time currents have pushed the algae — a regular resident of the Gulf of Mexico — over to the Atlantic side of the state.
In 1996, for instance, a pod of dolphins died off the coast of North Carolina under mysterious circumstances, according to Barb Kirkpatrick, a harmful algae bloom expert who is executive director of the Gulf of Mexico Coastal Ocean Observing System Regional Association.
"Nobody knew what it was, and then it turned out to be from Red Tide," she said. The dolphins had eaten fish that were poisoned by the Red Tide toxins, she said.
Since 1957, Red Tide has turned up 12 times on Florida's east coast. In 1997, for instance, it hit some of the same Palm Beach County beaches that were affected this past weekend.
The first time scientists recorded a bloom touching all three Florida coasts was in 1999. The east coast was hit by Red Tide again in 2002 and 2007. That last one persisted for months, and was blamed for the deaths of more than 40 sea turtles.
The current bloom has been labeled the worst to hit Florida in a decade. As of Sept. 29, Pinellas County work crews had hauled 767 tons of dead fish to the county's waste-to-energy plant and landfill, Levy said.
Senior news researcher Caryn Baird contributed to this report. Contact Craig Pittman at firstname.lastname@example.org. Follow @craigtimes.