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Home / Science / Florida's red tide is "natural", but pollution is making it worse

Florida's red tide is "natural", but pollution is making it worse



Vince Lovko, a phytoplankton ecologist at the Mote Marine Lab, earlier this month with a team of researchers, crossed the waters off Longboat Key in his Yellowfin fishing boat lab and sampled seawater from a red tide that formed almost around Southwest Florida had a year and scattered beaches with dead manatees, sea turtles and rotting marine life.

Every few meters, dead herring, grass eels and pinfishes floated by and scoured the water like a poisonous stew. The water, cloudy and yellowish, looked like it had been flushed out of a toilet.

Lovko is part of a team that tracks down the tides and seeks to fine-tune widespread satellite maps that make a large part of the state's gulf coast radiantly glow red-hot. But as Florida's summer of mud winds its way into the autumn, scientists like Lovko are in an uncomfortable situation: trying to wage a complicated and contentious political struggle in the midst of a heated election year in which their research is twisted by competing interests ̵

1; and sometimes the public gets confused.


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Mote Marine Lab researchers collected this 5-gallon pitcher of Longboat Key's crimson seawater earlier this month. Photo by Jenny Staletovich / Miami Herald

Shortly after Lake Okeechobee exploded with a huge blue-green algae blossom and flushed water managers to the coast, the red tide that had begun months earlier deepened and the worst fish killed in coastal waters off the Caloosahatchee River were fed, the western refuge of the great lake.

The agricultural sector and some state regulators pushed for any connection and called the red tide "naturally occurring". That's true. Outbreaks have been reported for centuries.

But a federal study, dating back more than a decade, excludes man-made pollution that aggravates the red tide. This makes the lake, which is rich in nutrients phosphorus and nitrogen, a likely source. What is not clear, since the same nutrients are flushed from the shore, is whether it is definitely a source.

"This is part of the work that still needs to be done to complete, or at least conclude," Lovko said.

One reason for this continuing uncertainty: Despite decades of recurring problems, the state has focused mostly on the persecution of red tides as soon as they arrive, not on the pollution that drives them. Over the last decade, water outperformance has been enhanced by state outtesting, which could help scientists understand the dynamics of the red tide while the agencies investigating water and regulating pollution are shrinking. Even the satellite maps that Lovko works on involve a great deal of inaccuracy when flushing toxic waters ashore.

"We think we understand that, but we're flying blind," said oceanographer Bob Weisberg of the University of South Florida by Karl Havens, an expert on blue-green algae at the University of Florida earlier this month. "We were never able to get the state of Florida to commit, and that hinders our ability to predict red tides."

Too much money is spent on bureaucracy, he said, and too little for actual investigation. [196592002] "That's the problem in Florida as long as I've lived here," said Weisberg, whose lab annually publishes red flood forecasts. "It's all political."

This is because some of the state's biggest political actors are also blamed for the worst environmental pollution.

This month, US Sugar released a press release stating that seawater had nothing to do with the Red Flood.

"The Florida Fish and Wildlife Conservation Commission (FWC) states in their Frequently Asked Questions that red tide is not caused by nutrient pollution (urban or agricultural) and, in addition, is not aggravated by it." The publication said. It also quotes Mote scientists from a Palm Beach Post story saying seawater has not "initiated" the tide. In fact, FWC's web page clearly states that once red tides are near shore, "they are able to use artificial nutrients for their growth." And two days later, Mote environmental engineer Tracy Fanara tweeted a clarification That lake releases could help maintain a flowering.

"If you have a [freshwater] cyanobacteria bloom, you know you have excessive nutrients [the cyanobacteria] it could decrease if it comes out," she said. "But it's still a sign, it's an environmental ecology response to high nutrients."

Scientists largely agree that the red tide, which consists of Karenia brevis algae Soil of the Florida shelf is sown. If the algae are near coastal waters that are polluted by a variety of sources, from fertilizers on lawns to leaky septic tanks, they can grow more intensely and form poisonous flowers.

"Once it blooms, it needs nutrients to bloom," Weisberg said. Redfish can help feed it, but algae can also use nutrients that flow from land, he said. "So, the lake runoff will not cause the red tide, but it can help maintain a red tide."

After a 2005 red tide exploded and continued for 17 months, fish in three states including Florida, the National Oceanic and Atmospheric Administration launched a six-year research project. The researchers concluded that the sources of nutrients that feed the red floods are "diverse, diverse and complex" and contain outflows from estuaries, such as those fed by Caloosahatchee.

What and how strongly these coastal nutrients affect is not well understood outbreaks, Weisberg said.

In a 2007 study, Larry Brand, a University of Rosenthal School of Marine and Atmospheric Research Phytoplankton Ecologist at the University of Miami, argued that increasing pollution has worsened red tide.

"It's a natural thing, it can go back 500 years, and what I'm arguing is that it's much worse today, and that's the result of man-made nutrients," he said. "Obviously it's political – there is not a single source and obviously some sources are more important than others."


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This satellite image, taken on August 21, shows the magnitude of the red tide in the Gulf of Mexico, said by National Stump and Oceanic R & D scientist Rick Stumpf on Wednesday that little has changed in the past week. Source: NOAA National Centers for Coastal Ocean Science

But Lovko, the Mote ecologist, is unconvinced and said Brand came to his conclusion on records containing inconsistent samples.

"One of the things we do not know about because there are no measurements, or adequate measurements of how much nutrients are flowing through the Lake Okeechobee's Caloosahatchee, actually comes from the coastal system," he said. "It's easy to make the assumption … That's what the public has accepted, but we can not, that's not how science works."

However, in his study, Brand stated that he had differences in sampling methods and methods accounted for a possible increase in surveillance that could distort the numbers. And he still found that between 1954 and 1963 and from 1994 to 2002 algae levels increased 13 to 18-fold.

What is not well understood is the fact that red tide explodes for several years and no other years and other species of phytoplankton hit the red tide on nutrient soup.


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Dead fish clog a channel of coral shore in southwest Florida earlier this month. Photo by Tiffany Tompkins / Bradenton Herald

Tiffany Tompkins [email protected]

Ocean water is filled with an abundance of phytoplankton that can absorb nutrients and fight for supremacy. Karenia brevis named after the retired algae expert Karen Steidinger, who conducted research at the St. Petersburg Naval Laboratory, exists in the Gulf waters, not just on the ocean floor. Scientists routinely find it near background concentrations near coasts in years when no fish are killed.

"We do not have a good understanding of what exactly controls the outcome of this competition, so variability is explained from year to year." Brand said. "There is no consensus at this time."

But to understand why the state of Florida Mote has nothing to do.

"What we need to finance is to monitor, we are not funded to answer specific questions," Fanara said.

Lovko says that there are also unanswered questions about the relationship between coastal and coastal populations of red-tip phytoplankton.

"What we do not know is like The offshore population is different, the supposed seed population that initiates and begins to move towards the coast, unlike the cells we already have," he said.

What kind of information could Weisberg, who supports his annual forecast, do to help? following the pattern of currents that carry algae ashore. When the migratory loop current of the Gulf crosses the West Florida Shelf, it pushes nutrients from the deeper bottom onto the shelf to fuel the Karenia algae.

"What is terribly lacking is the ability to go offshore on a regular basis, we believe the red tide is forming and scans the organism itself as well as the nutrients," he said.


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Mote Marine Lab researchers are investigating water from Longboat Key near Sarasota as part of a study of a sustained red tide along the coast in southwest Florida that has caused widespread fish mortality.

MATIAS J. OCNER mocner @ miamiherald. com

There are other knowledge gaps.

Scientists use satellite imagery to look at surface water to monitor the density of the red tide, but images are generally less precise the closer they get to the shore where information is most needed. On the coast tannins of mangroves and riparian vegetation and other organic molecules can interfere, Lovko. And it only works on sunny days.

The red tide of that year first appeared in front of Sarasota in October. It was deepened in June. Massive fish kills began to contaminate beaches and clogged canals with baitfish and larger marine life including sea turtles, dolphins, manatees and even a whale shark.

After the record rain that caused the US Army's engineering corps to flush water from the already blue-green algae-filled lake across the Caloosahatchee River, things got worse. The water from the sugar fields on the east side of the lake could also flow back from the spring channels into the lake, enough to cover about 48 square miles with one foot of water. The tides also coincided with a wave of Saharan dust, another source of nutrients for another algae that can feed red tide.

"We had a flower last year and it never went away completely," Weisberg said. "What happens this year is the confluence of two things: leftover cells from last year and new cells that came from the center of the continental shelf to the shoreline where the conditions of flowering were beneficial."


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<p>  Beyond polluted outcrops of farms, farms, ranches, and even phosphate mines, researchers are investigating other suspects who may have helped feed the newest flower. <span class= ▪ One idea is that Sahrawi dust is the same Wind-worn material that can dry out possible tropical storms could play a role. Researchers say the iron-rich dust may be Trichodesmium, a saltwater cyanobacterium that pulls nitrogen from the air so that it can grow in water with few nutrients. If African dust is heavy, it can drive trichodesmium, which can then be used for both offshore and coastal fish as food for red-flood algae.

The problem is that the theory has never been tested, said Joe Prospero, emeritus professor at the University of Miami Rosenstiel School of Marine and Atmospheric Science, nicknamed "Father of Dust."

"We have these different pieces and measurements were made of iron and it was modeled, but in real life there was no exact study," said Prospero, one of the first scientists to recognize the global effects of African dust. "It's just based on the fact that we measured seasonal dust here in Miami, but nobody has come to the west coast of Florida to my knowledge and has actually seen if there is a reaction and an increase of iron in the water." [19659055] Manatee Bay has been sucked.jpg ” title = “Manatee-Bucht ausgesaugt. jpg “/>

This photo of Michael Sechler shows a stranded manatee in Manatee County when Hurricane Irma dumped water on September 10th. (Michael Sechler on AP)

Michael Sechler AP

Some scientists also believe that hurricanes like Irma can have an impact. A hurricane, especially one as big as Irma, can carry huge amounts of water around the gulf. When Irma headed for the Gulf Coast for a second landing on Marco Island, he sucked water off the southwest coast, said the rose pedicle oceanographer Nick Shay. As the water flowed ashore, it came from the lower strata where Karenia brevis thrives.

"We need to understand not only the surface currents, but also the bottom currents," he said. "If we start putting this together, maybe the whole Irma thing was a preconditioning state."

Deepwater oscillations generated by hurricanes may also continue for a prolonged period, possibly pushing more algae to the coast, he said.

So while the surface layer is back to normal, what happens in the deeper layers may take a month or more. "Whether the lake releases red waves or not, scientists emphasize that the harmful blue-green algae are blooming Pollution of coastal waters alone is an overhaul of research and standards in water quality, and solutions for individuals may vary." [19659011] "They are taking a red tide completely out of this image and it in no way reduces the compelling argument for reducing [pollution] in Lake Okeechobee," Lovko said. "Something has to happen."


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Vince Lovko, a phytoplankton ecologist, uses a spectroradiometer that measures light in water to detect the intensity of the red tide off Longboat Key near Sarasota. The Red Tide first occurred in October and has since spread along the southwest coast of Florida.

MATCAS J. OCNER [email protected]

Scientists say instead that more research must be focused on finding causes, not just surveillance. Since this year's red tide has developed into a major crisis that damages businesses and raises national headlines, Scott has declared a state of emergency and spent $ 6 million to help with clean-up and tourism. But Weisberg is worried that this is only an election year.

"I've been very successful in making people mad at me, but eventually, how do you change? It's politics. Mote has a lot of money, why? Because they're connected," he said. "If we do not talk about serious issues in detail, we'll never change anything."

Follow Jenny Staletovich on Twitter @jenstaletovich


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