Sayer Ji
Founder of

Subscribe to our informative Newsletter & get two FREE E-Books

Our newsletter serves 250,000 with essential news, research & healthy tips, daily.

Easy Turmeric recipes + The Dark Side of Wheat

The Truth About Red Tide's Manmade Causes and Health Effects

The Truth About Red Tide's Manmade Causes and Health Effects

The Red Tide we are experiencing now is not a "natural phenomenon," and is having adverse health effects on exposed populations far beyond what local health and environmental authorities are willing to admit. We need to commit ourselves, organize and catalyze reform, or the Gulf of Mexico will turn into a festering Petri dish and we the uninformed object of experimentation.

If you consult the websites of the Florida Fish and Wildlife Conservation Commission or the Mote Marine Laboratory, both considered authorities on marine environmental issues in the state of Florida, red tide outbreaks associated with Karenia brevis are "natural phenomena," 'beyond our ability to control,' and explicitly not fed by nutrient pollution or causally linked to land-based, human activities.  And yet, longtime residents of the Florida Gulf coast (the author included) can tell you from first-hand experience that the blooms have been getting progressively worse, closer to shore, and persisting for a greater length of time, indicating that if it is an entirely natural cycle, it has undergone concerning changes of late.

The reality is that authorities who deny the involvement of land-based activities and algae blooms are conveniently ignoring the science, which is peer reviewed and published, that instructs us on what is feeding red tide near shore. Florida has only so many industries that sustain its fragile economy, many of which would have to enact substantial, and costly reforms in order to improve the environmental situation. The tourism and real estate industries also have a vested interest in minimizing and/or denying the extent of the problem, at least in the short term. The long term outlook, however, is dismal for these industries, who failing to act, would see the primary attractor for tourists or potential buyers of real estate -- the Gulf of Mexico -- transformed into a Petri dish. It is for this reason that the truth about red tide must gain a wider audience, and we hope, widespread acceptance.

How Red Tide Is Measured and Misleadingly Contextualized For the Public

Since late September last year, the Southwest Florida Gulf Coast has been under siege by laboratory-verified blooms [see Status Maps], growing to its present state of significant outbreaks of a million cells per liter or higher, and stretching all the way from Manatee County to the Florida Keys. This is one of the worst red tide outbreaks in recorded history.[i]

Karenia brevis levels are measured by state environmental authorities using the cells/liter scale as follows:

  • Not Present – Background (0-1000)
  • Very Low (>1,000 to 10,000)
  • Low (>10,000 to 100,000)
  • Medium (>100,000 – 1,000,000)
  • High (>1,000,000)

These figures, however, are quite misleading.  Using colloquial expressions such as "Very Low" to describe concentrations of Karenia brevis of 1,000 to 10,000 cells per liter does the public a disservice, as they are serious enough to lead to acute symptoms of respiratory irritation and shellfish harvesting closures.

So-called "Low" levels, or 10,000 to 100,000 cells per liter, can cause fish kills.  Once you get to "Medium" and "High" red tide represents a serious health threat to exposed populations, keeping in mind that one does not have to be "at the beach" to be affected, as red tide brevetoxins are aerosolized (made airborne) via wave action, and can be carried on the wind many miles inshore.  In fact, at so-called "Low" levels >50,000 cells/liter the saturation of Karenia brevis is already significant enough that it can be detected by satellite.

At present, levels along the affected Southwest Florida Gulf Coast have reached "High" in several areas, including off the coast of Lee County where I am presently reporting from. I can speak directly from experience that this is a particularly noxious outbreak. For instance, I had a bronchial asthma attack for the first time in 20 years and have found myself, my family, and the local community I serve to be at greatly increased susceptibility to prolonged cold and flu bouts, over the past five months.

Another important consideration is that red tide sampling occurs primarily in surface water (80% surface sampling; 20% bottom sampling). The problem is that Karenia brevis blooms have been found to penetrate coastal waters along the bottom without surface expression until nearshore. This means that "negative" surface findings do not necessarily indicate the absence of a problem.

So, What Is The Real Cause of Prolonged, Near-To-Shore Red Tide Outbreaks?

So, back to the question: are these outbreaks an entirely natural phenomenon, as many health authorities, and certainly folks within the mainstream media, tourist and real estate industry, often maintain?

The answer is a resolute and resounding NO.  In April, 2009, the journal Aquatic Microbial Ecology published a groundbreaking study titled, "Grazing by Karenia brevis on Synechococcus enhances its growth rate and may help to sustain blooms," which provided the missing link in how red tide is directly fed by human, land-based activities.  Here is the study abstract:

ABSTRACT: Grazing rates of Karenia brevis Clones CCMP2228 and CCMP2229 were determined in laboratory experiments using Synechococcus sp. Clone CCMP1768 as food. Grazing by K. brevis thus enhances the range of nutritional substrates available to meet its growth requirements, and may play a substantial role in sustaining natural populations in inorganic N-poor waters. With evidence that blooms of Synechococcus can be enhanced due to anthropogenic nutrients, the poten­tial importance of this particulate nutrient source for sustaining red tide blooms in situ is large and may help to resolve the current uncertainty as to how K. brevis blooms are maintained. It can now be hypothesized that as cyanobacterial blooms increase, so too does the potential for Karenia brevis growth to be enhanced and for blooms to be sus­tained through grazing, especially under the low light conditions associated with bloom self-shading. Recog­nition of this pathway is at least one step toward recon­ciling the long-term reported increase in K. brevis blooms (e.g. Brand & Compton 2007) and the tendency for blooms of this species to develop offshore in seem­ingly oligotrophic waters (e.g. Vargo et al. 2004, 2008)

What this research essentially proves is that the runoff from land-based applications of urea nitrogen fertilizers such as commonly used in lawn care, as well as additional sources of nitrogen urea from septic tanks, sewage spills and close-to-water sewage treatment effluent, result in Synachoccus blooms, which is a harmless, green slime algae (have you noticed the green slime at your beach?). Karenia brevis (red tide) uses the green slime as an energy source. The more Synachoccus the more red tide; simple cause and effect.

At the root of the problem are nitrogen urea fertilizers, which are overused in Florida lawn care practices, as well as in Florida agriculture (more on this later). According to a Sierra Club report linking fertilizers to Red Tide blooms, residential fertilizer use in the state of Florida increased by 153,533.95 tons or 45% from 2003 to 2006 alone.[ii] One might ask the question to Floridians: is the "health" of your lawns (read: aesthetic appearance) more important than the health of the Gulf of Mexico (and by implication, your own health)?

Ironically, plants need primarily magnesium (for chlorophyll) and potassium, and not nearly as much nitrogen, which is presently being used at up to 5 times higher levels than required. In fact, excess nitrogen leads to plasmolysis in plants, causing excess water to leave the plant entering the soil, resulting in wilting. The excess nitrogen, of course, leaches into the soil and eventually a portion of its causes water pollution.

The obvious solution to the accelerating red tide problem is to reduce land-based applications of urea nitrogen, especially in the summer months. As the green slime is reduced, the red tide will have no additional energy source and will die out.

How Red Tide Adversely Affects Human Health

In order to understand how red tide affects human health, one must first understand brevetoxins, the primary "poisons" produced by this organism.

There are at least 9, and as many as 14, brevetoxins divided into two classes: Brevetoxin A and Brevetoxin B, with 3 subtypes characterized among Brevetoxin A and 4 subtypes among Brevetoxin B.

Brevetoxins are extremely toxic.  The brevetoxin B subtype, PB-TX2, for instance, has an oral LD50 (the acutely lethal dose that kills 50% of the test group) equivalent to cyanide (6 mg/kg) at 6.6 mg/kg in the 24 mouse model of acute exposure. No one truly knows the extent of the synergistic toxicity associated with exposure to all 9-14 brevetoxins simultaneously, which is what may occur in real-world exposure, because it has not (to my knowledge) been researched.

Brevetoxins are known primarily as a neurotoxic. They bind to voltage-gated sodium channels in nerve cells, leading to disruption of nerve transmission and in some cases nerve cell death.  Animal research indicates that as little as 2 days of subacute exposure to the Brevetoxin B, PbTx-3, is sufficient to induce neuronal degeneration in a discrete reason of the mouse cerebral cortex.[iii]

In humans, a condition known as Neurotoxic Shellfish Poisoning (NSP) caused by the consumption of shellfish contaminated by brevetoxins has been identified. Symptoms include vomiting and nausea and a variety of neurological symptoms such as slurred speech.[iv] Of course, lower concentrations, especially in more susceptible populations already suffering from neurological issues, likely contribute to these symptoms, as well as headache, myalgias (muscle soreness), and related aches and pains that would be hard to attribute to such an invisible toxin, whose health threat is generally downplayed by the media and medical establishment.

Neurotoxicity, however, is only the tip of the iceberg. A 2004 study, published in the Journal of Toxicology and Environmental Health, found that the immune system, and not the nervous system, is the primary target of brevetoxins.[v] Animals exposed to brevetoxin saw a more than 70% suppression of humoral immunity.  A 2005 study confirmed this finding.[vi]

Then, in 2011, it was found that brevetoxin A inhalation worsens the pulmonary response to influenza A in the male rat. [vii] The study authors concluded: "These results suggest that repeated inhalation exposure to brevetoxin may delay virus particle clearance and recovery from influenza A infection in the rat lung."

This finding indicates that Red Tide blooms may therefore worsen the seasonal flu epidemics that commonly afflict the Southwest Florida, especially when the bloom persists into the fall and winter months, as is the present case. 

It is already well known that hospital verified cases of respiratory issues can increase by over 50% during sustained Red Tide outbreaks.[viii]

Considering that much of the mortality associated with influenza infection is associated with pneumonia complications, reducing Red Tide outbreaks via fertilizer use reductions should be considered a top priority by health authorities.

But the adverse health effects do not end with neurotoxicity and immunotoxicity, as serious gastrointestinal complaints may also follow from Red Tide exposure.  A 2010 study examined whether the presence of a Florida red tide bloom affected the rates of admission for a gastrointestinal diagnosis to a hospital emergency room in Sarasota, FL.[ix]  According to the study:

The rates of gastrointestinal diagnoses admissions were compared for a 3-month time period in 2001 when Florida red tide bloom was present onshore to the same 3-month period in 2002 when no Florida red tide bloom occurred. A significant 40% increase in the total number of gastrointestinal emergency room admissions for the Florida red tide bloom period was found compared to the non red tide period.

We can therefore add gastrointestinal issues to the growing list of Red Tide associated health issues. Other potential health effects that have been noted in the biomedical literature include:

So What Can Be Done?

1) REDUCE EXPOSURE: First, if you live in South Florida, remember to monitor your area's levels by visiting the Status Maps. Please keep in mind that proximity is not the only factor in exposure, due to the well known aerosolization of these toxins and the inability of surface water testing to fully reveal its presence.

Next, visit the site, to see if the winds are moving inshore, or going offshore. This simple step may enable you to reduce exposure, by reducing time outside, and certainly keeping off the beach, on days that aerosolized Red Tide brevetoxins may be moving inshore. Also, consider that if you are driving, keep the air circulating within the cabin. Unfortunately, there is nothing you can do if your AC unit is continually pulling air from outside inside your home, but you could reduce your AC usage on these days. Eating cooling foods, and wear lighter clothing, for instance.

2) REDUCE TOXIC EFFECTS: The primary mechanism through which brevetoxins cause respiratory harm is through IgE-independent mast cell activation.[x] Mast cells are immune cells which if over-activated can produce a wide range of potentially harmful substances, such as:

  • Histamine (inflammatory)
  • Thromboxane (vasoconstrictive)
  • Prostaglandin D2 (brochoconstrive)
  • Leukotriene C4 (bronchoconstrictive)

Keeping this in mind, preventing mast-cell degranulation with safe, non-drug alternatives such as nettle's extract may be an ideal approach to the problem. Several companies provide extracts which concentrate the compounds within nettle's that inhibit mast cell degranulation, e.g. New Chapter's Histamine Take Care, V!ah's "Allerblock."  While we do not endorse any product, as this runs counter to our mission statement (you will see no ads on for any dietary supplement) we feel compelled to inform our readers that alternatives to antihistamine drugs like Benadryl do exist. Also, please remember to do your own research in tandem with consulting a licensed health care practitioner before embarking on a path of self-care. Other potential histamine-blocking compounds that have been researched can be found on our histamine antagonist page: Histamine Antagonist

3) CONTRIBUTE TO THE LONG TERM SOLUTION: The long-term solution is to reduce the use of nitrogen urea fertilizers in both lawn and agricultural applications. There is no question that nitrogen urea rich agricultural runoff, primarily from the sugarcane and citrus industries, are sizable contributors to the overall nitrogen burden in the Gulf of Mexico. Much of Big Sugar's agricultural runoff ends up in Lake Okeechobee, which eventually empties into the Gulf of Mexico.

A 2006 study published in the journal Biogeochemistry titled, "Escalating worldwide use of urea – a global change contributing to coastal eutrophication," indicates worldwide use of urea as a nitrogen fertilizer and feed additive has increased more than 100-fold in the past 4 decades. The study pointed out:

Long thought to be retained in soils, new data are suggestive of significant overland transport of urea to sensitive coastal waters. Urea concentrations in coastal and estuarine waters can be substantially elevated and can represent a large fraction of the total dissolved organic nitrogen pool. Urea is used as a nitrogen substrate by many coastal phytoplankton and is increasingly found to be important in the nitrogenous nutrition of some harmful algal bloom (HAB) species. 

They also noted that "the global increase from 1970 to 2000 in documented incidences of paralytic shellfish poisoning, caused by several HAB species, is similar to the global increase in urea use over the same 3 decades."

The reality is that these agricultural practices have been a long time in the making, and will take considerable time, energy and political clout to change. The good news is that you can make changes at the local level, from the bottom up, as it were, by starting with your own lawn. You can also organize at a county level to enact ordinances that restrict fertilizer use, as Ed Rosenthal, founder of the non-profit organization Advocate the Precautionary Principle, has done with great success in Sarasota county. These results are encouraging, and indicate that we can build a grassroots movement with an end goal to enact stricter regulations at the state level.

Stay informed about this issue by joining the Facebook page: Red Tide Has Manmade Causes and Grave Health Effects


Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of GreenMedInfo or its staff.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Red Tide and GeoEngineering

I grew up on the beach in Southern California so I was interested in your article on red tide. One thing that you did not mention in your article is the iron and nutrition added to our oceans to supposedly solve the climate change issue. I have many documents with images and diagrams on feeding the red tide as a climate control tool. Given the dramatic increase in red tide I do not think it is totally from natural human activities. Red Tide "feeding" was clearly spelled out in the Asimlomar II Geo-Engineering conference. My coverage of the conference can be found at As a side-note. When I grew up the red tide was glowed green at night. I was recently writing an article on the phenomena and all the images that I could find were a blue glow. It appears as though the dinoflagellates glow in a different frequency these days. From the trenches, Celeste

Soluble chemical fertilizers

Florida opposes EPA standards and FDEP has held a delaying pattern for over 50 years using erroneous "scientific" studies. Industry lawyers have taken the issue to nauseating lengths to maintain profits at dire expense to our environment. Well to address this "root" problem...water, agriculture, seafood and human health are not optional. From a Miami Herald article...."Numerical limits on pollution are expected to strengthen enforcement. Opponents argue that the federal rules would be too expensive to implement and favored the state's approach." During recent decades, Florida's DEP tested every ditch and mudpuddle to establish "numerical limits." While the State squandered millions in a futile effort to delay action, the writing was on the wall. Soluble chemical lawn and farm fertilizers have always been the big problem, soluble being the key word. And "soluble" implies water waste, aquifer depletion and pollution; dead zones, dead coral reefs, fouled springs, flesh eating bacteria and the loss of seafood, recreation and tourism. Sewage treatment also escaped regulation as municipalities took the cheap path of pumping poop into the ocean or otherwise held to antiquated technologies. Too expensive for who? Mia Herald..."Winston Borkowski, a lawyer who represents phosphate, wastewater and electric utility companies, said Thursday that he wants the EPA to set rules so his clients have some certainty about what they will have to pay in regards to regulation." Lawyers and lobbyists have protected industry profits for over 50 years with total disregard of the public and our common environment. It is time to get real on costs and who actually pays! Mia Herald....""These are the folks that are actually going to be affected by the criteria," he said. "That means spending money. They have to budget to know what the future is to comply with the regulations. One way or the other, we want the state and the EPA to get together so we know what the future is from a regulatory perspective."" The public has not been properly informed and few are aware of the dangers of chemical or genetically modified agriculture ( GMOs ), or of spreading 6-6-6 on a lawn, or even the importance of food and water sustainability under ever more fickle climatic conditions. Cuba, just 90 miles to the south stands as the undeniable case study. In nearly identical environments the absence of embargoed fossil fuels, chemical fertilizers and pesticides is clear. Cuba, for all its political faults, has retained pristine forests and coastal waters with a great diversity of species. Cubans enjoy statistically better health than Florida immigrants. Compared to Cuba, Florida is an ecological disaster. The solutions are obvious and intertwined with our system of chemical agriculture and fossil energy. We need to, at the very least, ban solubles in favor of slow release nutrients that stand a chance of being absorbed by plants before rains wash them into the aquifers or the ocean. Optimally we would return to a more diverse biologically sensitive agriculture using permacultures, pastures, composts, manures and a greater diversity of useful plant species; not water-hungry corn monocultures, CAFO (feed lots) or St. Augustine lawns. Monies should be spent on waste infrastructure and clean energy. Instead of mechanizing, millions of displaced people should be involved in local sustainable agriculture. If anyone thinks The State of Florida is looking out for your water and environs consider the growth of subsidized pivot irrigation systems and the trillions of gallons pumped out of the aquifer daily for the sake of growing phony hazardous GM corn. Most of this corn is used to feed animals confined in crowded unhealthy conditions that require drugs, antibiotics and hormones just to provide poor quality meats, milk and eggs so riddled with dangerous bacteria it must be cooked at high temps and pasteurized. Huge pumps run day and night draining aquifers along with nearby lakes and creating sinkholes...for what? And we are told to turn off the faucet while brushing teeth, don't wash the car or flush the toilet while ignoring this exponentially extravagant squander of our water and ecology. Now water management is under greater centralized control which enables industrial farming, chemical/mining/biotech/oil/bad food/disease/ pharmaceuticals...corporate monopoly/unemployment/ environmental devastation.

The Red Tide

I really appreciate your integration of news, research, personal experience, advocacy, and self-care advice. By including links to the maps readers can better appraise developments along the Gulf coast. In attempts to get to the source of an environmental health problem, which in this case is excess urea nitrogen, copper sulfate runoff, excess phosphate, and other causes of harmful algal blooms, advocates run into obstacle course studded with entrenched business interests and biased interpretations of scientific data. The conflicts of interests cannot be ignored. When there's an elephant in the room, we need to introduce it for what it is without demonizing the people interpret the data to their liking and who oppose action because they feel that their livelihoods or ways of living are at stake. We must appeal to common sense and look for paths of least resistance to workable solutions. The longer the precautionary principle gets slapped aside by arguments related to jobs, corporate profits, or politics, the greater the risks to human health and the health of ecosystems. We just have to keep pounding away while being sensitive to political and economic realities, showing why the integrity of biological systems should be our priority. The precautionary principle needs a networked public relations team to get the news out there. The red tide problem could serve as a symbol for our global environmental health dilemma, namely, the tide of people and corporations who see red whenever an environmental concern threatens to move their cheese, resulting in pitched battles that get in the way of common sense solutions. Sayer, you and your team do an outstanding job of tying things together. Thank you for the wok you do. We need more people to follow your example.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
Login or Register to write a comment

Key Research Topics

Sayer Ji
Founder of

Subscribe to our informative Newsletter & get two FREE E-Books

Our newsletter serves 250,000 with essential news, research & healthy tips, daily.

Easy Turmeric recipes + The Dark Side of Wheat

This website is for information purposes only. By providing the information contained herein we are not diagnosing, treating, curing, mitigating, or preventing any type of disease or medical condition. Before beginning any type of natural, integrative or conventional treatment regimen, it is advisable to seek the advice of a licensed healthcare professional.

© Copyright 2008-2018, Journal Articles copyright of original owners, MeSH copyright NLM.