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Flood Tide

Was red tide just the beginning?

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On Nov. 23, Black Friday, the United States Global Change Research Program (USGCRP) released its fourth quadrennial National Climate Assessment. Former vice president Al Gore accused the Trump Administration of burying the report by releasing it on a consumer holiday. But the tone of the document was, in some ways, fitting for Black Friday. All is not well, according to the agency tasked with studying climate change since 1990.

Climate change is real and it’s accelerating. Florida, especially, is already feeling its impacts. Among those impacts are dying coral reefs, high-intensity hurricanes, extreme coastal and inland flooding, mosquito-borne illnesses, invasive species and toxic algae blooms.

The state’s recent red tide epidemic is an indication of what’s ahead. The phenomenon came to the attention of the public this year, through news headlines and alarming photos of dead, rotting fish strewn across Gulf of Mexico shorelines.

Scientists have been studying toxic algae blooms for a lot longer. What we call red tide is just one variety of Harmful Algal Bloom (HAB). The organism that causes red tide is Karenia Brevis, but there are others—some found here in the waters of Northeast Florida—that can be just as deadly and disruptive to local economies.

Algae are, of course, natural and normal under natural and normal circumstances. HABs happen “any time you have an excess growth of algae,” said Dr. Larry Brand, a professor at University of Miami’s Rosenstiel School of Marine & Atmospheric Science. That’s when these algae become toxic to living organisms, including people. According to Brand, about 1,500 species of these toxic algae exist all around the world. The active toxin in red tide is Brevetoxin. It can create respiratory issues for humans and animals. It can also kill organisms living in the water, as we’ve seen this past summer.

This year, Southwest Florida experienced the worst red tide outbreak since 2006. There is currently a bloom between Tampa Bay and Naples that first appeared in October 2017. Low to medium concentrations still persist in several counties.

The outbreak has taken a toll on the health of residents there. Brand referenced studies that document a 50 percent increase in hospital visits for respiratory distress and a 40 percent increase in gastrointestinal disorders.

While red tide’s K. Brevis is found exclusively in the Gulf of Mexico, there are other organisms that can cause HABs. The blue-green algae Cyanobacteria that inhabits the St. Johns River is also toxic, though its effects are slightly different. And it hasn’t yet erupted into a HAB.

Brand described HAB formation as a perfect storm of natural and manmade factors.

“While these things do occur naturally, just like blue-green algae, what we’re doing as humans are triggering these blooms more frequently or making them worse,” he said. “You already have [natural] phosphate. What you need is nitrogen. Algae need both nitrogen and phosphorus. So, if you have phosphorous but no nitrogen, then you can’t get a bloom. But now humans are dumping lots of nutrients [nitrogen] into our waterways and down into the West Florida area where the blooms are occurring.” These nutrients come from fertilizer, agriculture and wastewater.

“I looked at 50 years of data,” Brand continued. “What I found is, today, the red tide blooms are 15 times more abundant on average than they were 50 years ago. So in a time span of 50 years, yes, the red tide has gotten worse. Now, if you get 15 times more red tide, you need 15 times more nutrients and I can’t think of any natural sources that have increased that much. What has increased dramatically is the number of people in South Florida.”

In addition to researching red tide, Brand is also one of the scientists currently studying Northeast Florida’s blue-green algae—and the hazards it can pose in a HAB.

“There’s a bunch of different toxins produced by the blue-green algae,” he said. “The one that people know the most about is Microcystin. This could lead to things like, well, eventually liver disease and liver cancer.” Blue-green algae is also linked to another type of toxin, BMAA, believed to lead to long-term degenerative disorders like Alzheimer’s, Parkinson’s disease and ALS.

The St. Johns Riverkeeper is aware of the dangers generated by a potential HAB. The local nonprofit is also sensitive to the causes of such HABs.

“You really have to stop the pollution at its source,” said executive director Jimmy Orth.

The organization is working to prevent a toxic outbreak by reducing the amount of nutrients coming into the waterways.

“The thing about the blue-green algae is that what we’ve seen in the St. Johns and other areas, is that can actually be aerosolized,” said Orth. “This means that the toxins can be released into the air when the water is disturbed, putting boaters and anyone near the water at risk.”

Such an outcome would be a disaster for both public health and the economy. This year’s red tide outbreak in Southwest Florida has made the environment a hot topic politically—finally.

“Our economy is so intricately tied to tourism and what we’ve seen in South Florida has really been a wake-up call,” said Orth. “Obviously, it’s the first time I’ve ever seen politicians debating on who’s going to do a better job at protecting the environment.”

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