Red tide is always bad. Global warming is making it worse, researcher says

A chain reaction started in Europe about 260 years ago, thousands of miles from Florida, and the effect — climate change — is now punishing Manatee County, especially when it comes to red tide.

Scientists and entrepreneurs met at the University of South Florida Sarasota-Manatee to discuss climate change on Friday. Among them was Robert Corell, a principal at the Global Environment Technology Foundation.

“It began in England with the discovery that we can take coal and we can make energy out of it,” Corell said. “We can build the future of humankind in a way that had never been thought of before.”

Harmful emissions spiked dramatically at the onset of the Industrial Revolution. Scientists know that, he said, because they measure greenhouse gases that were captured in ice — a time capsule of the atmosphere.

A similar increase is true for the world’s population, which grew from less than one billion people in 1751, to about 7.7 billion people in 2019.

Read Next

The speakers outlined rising sea levels, worsening hurricanes and suffering industries. They also highlighted a familiar problem in Manatee County: severe, prolonged cycles of red tide.

As a resident of Longboat Key, the recent blooms were personal for Lenny Landau. He pointed to vacant restaurants and canceled hotel reservations, along with the dead fish and respiratory irritation that comes with red tide.

Blooms of red tide are a risk to the environment, public health and the economy.

Read Next

“If somebody was at war with the state of Florida and they wanted a weapon to come after us, it’s clear that red tide would be perfect, because red tide impacts everything,” he said.

Landau prefaced his speech by saying he was an engineer, not a scientist, though both are motivated by curiosity and problem solving.

He studied red tide for several months and concluded that rising sea levels would eventually be a local concern. However, through the work of another researcher, his focus shifted to red tide.

“I know about sea rise,” he said. “It doesn’t affect me right today, but red tide affects all of us today or tomorrow.”

Florida’s red tide originates from a microscopic organism, Karenia brevis, which occurs naturally in the Gulf of Mexico. It’s the only organism of its kind, mainly because it leads to dead fish, shellfish poisoning and human respiratory irritation, according to Friday’s presentation.

“There is no other organism in the world that does all three,” Landau said. “When you hear about red tide in Boston or someplace else, this is not it. It’s different — this is our red tide.”

A problem begins when nutrients are pulled from deep below the Gulf. They move up a continental shelf before traveling near the ocean’s surface, alongside the red tide algae.

And while the algae is already fed by nutrients in the Gulf, it finds more nourishment near the shoreline. Red tide is fed by wastewater leaks, spills or dumps, along with fertilizers and stormwater runoff.

So how does climate change affect red tide once it arrives at Manatee’s shoreline? Red tide often appears in late summer and then fades by early winter, but the cycle is changing.

“You’d have a bloom, it goes away, people forget about it — that’s it,” Landau said. “In my opinion, we’re at a point where we have to do something. If we don’t, some of these things are going to be long term.”

Cold water usually wards off the algae before tourists arrive, he said, but warmer temperatures made a suitable home for red tide. As a result, red tide bloomed in the fall of 2017 and then extended through 2018 and into this year.

“Red tide is impacted by climate change, not because the water is getting warmer, but because it isn’t getting cold enough,” Landau continued.

Little was known about the relationship between climate change and red tide. Facing a lack of information or support, Landau encountered a sense of hopelessness, but he ignored the naysayers and carried out his research.

Some ideas are overwhelming. For example, he said, it’s not clear how locals would address the flow of iron-rich dust clouds from Africa to Florida, which may feed red tide.

But other solutions are more realistic for Manatee County and its neighboring communities. Some organizations are working on new or refined technology, including Mote Marine Laboratory, in Sarasota.

In the meantime, residents can focus on voicing their concerns, reducing the use of fertilizer or curbing sewage and stormwater runoff. The ultimate goal is to starve red tide and lessen its impact.

“It occurs naturally,” Landau said. “We’re not going to argue with that. However, climate change is enabling it to be here year-round, and man-caused pollution is fueling it.”