Red tides can be a triple threat to the Gulf Coast, doing harm to public health, the tourism economy and the seafood industry. A forum held Thursday in Mobile suggested that in the absence of a sweeping cure, there is still room to improve responses.
Alison Robertson, an assistant professor at the University of South Alabama and a senior marine scientist at the Dauphin Island Sea Lab, said a lot is known about Karenia brevis, the algae whose toxic blooms have plagued part of Florida’s west coast this fall and which recently shut down Alabama oyster harvesting.
However, she said, scientists still have a lot to learn about how other environmental factors contribute to K. brevis' red tide blooms. Temperature, salinity and other factors all come into play, she said, and in a complex environment such as the coastal waters around Mobile, those interactions aren’t always well understood.
She described it as a complex problem "that we still don't have a handle on."
Robertson was part of a panel that included one of the area's top tourism officials, Herb Malone of Gulf Shores & Orange Beach Tourism, as well as a scientist turned oyster farmer, Charles A. Wilson III of Navy Cove Oysters on the Fort Morgan peninsula. The panel, moderated by LaDon Swann, director of the Mississippi-Alabama Sea Grant Consortium, was itself part of a much larger event: The 2018 Bays & Bayous Symposium, a biennial gathering of marine scientists held Wednesday and Thursday in Mobile.
Robertson, Wilson and Malone had distinctly different perspectives, yet agreed on some key points: Communication helps organize a measured response to red tide. Better testing would be a key step toward accurately assess the threat level. And for the state to be able to offer a reliable red tide forecast would help everyone plan.
Malone said that the fall season, when red tide blooms tend to be most severe, features a lot of weekend events along the coast. A bloom can create health hazards for anyone in the water, and if severe enough, can make it unpleasant even to be near the water. Local officials don’t want to downplay a health issue, but also don’t want to needlessly turn away visitors. “Anything that threatens that economy has ripple effects throughout,” he said.
Officials such as himself depend on scientists to translate their observations into real-world advice. And they do what they can to facilitate communication among governments and public safety agencies. When there’s a red tide threat, he said, they discuss it much as they would a risk such as rip tides. The goal is to reach an informed consensus and help others, such as lodging operators and event producers, make informed decisions.
That's all good, he said, but it's mostly reactive.
"We need predictability," he said. People tend to get a solid warning when a hurricane is on the way, he said, but with red tides, "right now it seems to be very unpredictable."
Wilson likewise said that better prediction of algae blooms would help oyster farmers such as himself in several ways. If they knew the risk was rising, for example, they could ramp up their harvest to stockpile oysters before the state imposed a shutdown.
Testing currently imposes a sort of bottleneck on the process, the panelists agreed. The method used is somewhat archaic and is done out of state, with samples sent to Florida. That limits the amount of testing Alabama can afford to do, so it takes a very conservative approach: If it finds a dangerous level of red tide toxin in any test results, that triggers a blanket shutdown on all oyster harvesting in the state’s coastal waters.
Wilson said he thinks it's important for the public to understand that these are "precautionary closures." High concentrations of K. brevis can contaminate oysters, but shutdowns are imposed before that actually happens. They're then maintained until the threat has receded.
The state closed shellfish growing waters in Mobile and Baldwin Counties on Nov. 16, citing a finding of K. brevis cells exceeding standards. A few days later, it issued a more specific advisory to the general public:
“The Alabama Department of Public Health cautions the public that water samples collected from Alabama Point to Little Lagoon Pass in Baldwin County indicate the presence of red tide cells in the low to medium range,” it said. “Persons with respiratory problems or those experiencing symptoms of nose, throat or eye irritation should avoid any mist generated by these waters. In addition, fish kills are possible in this area because of red tide."
”ADPH will continue to monitor gulf and bay waters for the presence of red tide cells," concluded the Nov. 21 advisory. “Unfortunately, the presence of red tide cannot be predicted to be at a certain location at a certain time. The effects depend on many variables such as temperature, salinity, direction of the wind, and how concentrated the organisms are at a given location.”
Robertson offered some hope on the testing front, saying Florida was investing in the development of a newer, faster method. She speculated that if Alabama could one day conduct a better regimen of testing, it might have to rely less on blanket closures. Better mapping of currents and salinity exchanges would also help develop a system of closure zones, she said.
At last some of the tools are already out there, she said.
“There’s a lot of great technology that’s available, we just don’t have funding for,” Robertson said.