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Photo Credit: Richard Graulich/The Palm Beach Post via AP
Florida is once again under the dual assault of toxic green algae and red tide blooms, both of which result from land-based, human activities. Yet the media, FL marine organizations like MOTE, and government agencies like the Florida Fish and Wildlife Conservation Commission, continue to deny the scientific evidence that humans are both responsible for, and thereby capable of undoing, this environmental disaster.
Scientific, peer-reviewed, published articles such as the one we will discuss below by the University of Maryland’s Center for Environmental Studies, have found that Red Tide blooms of Karenia brevis algae use cyanobacteria blooms -- so-called "green slime" -- as a food source. These cyanobacteria bacteria blooms are a direct result of the following three forms of man made pollution:
- Shore-based sewage spills of urea nitrogen from planned county sewage discharges
- Septic tank leaks of urea or urea nitrogen leaching from lawn applied organic urea on lawns near shore
- Lake Okeechobee releases which contain nitrogen and phosphorus from cattle ranches, farms, and neighborhoods as far north as Orlando.
It’s a simple chain of cause-and-effect events: Manmade activities and industries pollute the environment with nitrogen and phosophorous rich nutrient run off. These feed the cyanobacteria green slime. The Red Tide organism feeds off of the green slime, blooming as a result.
Blatantly Denying the Obvious Causes
The primary causes of the increasing frequency and intensity of red tide blooms over the past few decades in the Gulf of Mexico are not a mystery as frequently represented by the media. They are direct results of increased human activity, industry and development, all of which have grown in lockstep with this growing environmental disaster.
Despite this, prominent watchdog agencies for environmental issues, such as MOTE marine laboratory and aquarium out of Sarasota, maintain that, “there is no direct link between nutrient pollution and the frequency or severity of red tides caused by K. brevis,” in answer to the question “Has coastal (nutrient) pollution caused the Florida red tide?” on their website. Interestingly, the Florida government website for Red Tide monitoring, parrots this mistruth to the same question with same denial verbatim under their Red Tide FAQ’s.
MOTE Marine Lab's official statement on the matter.
Florida Fish and Wildlife Commission's oficial statement on the matter.
We can only assume this denial serves economic and political agendas, as the tourism and real estate industries would suffer incalculable losses if the true extent and health hazards of this problem were discussed with any degree of honesty.
But the truth cannot be suppressed for much longer. There is a growing movement, spearheaded by local activists like John Heim, founder of the SWFL Clean Water Movement, and Erin Brockovich who posts about the issue regularly on social media, to hold accountable both the polluters and those who collude with them to deny that anything can be done beyond further monitoring and improved detection.
Toxic “Guacomole Sludge” Contains Perfect Food for Red Tide Organism
Titled, "Grazing by Karenia brevis on Synechococcus enhances its growth rate and may help to sustain blooms," the study demonstrated that red tide is directly fed by the “green slime” which grows as a result of human, land-based activities. Here is the 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)"
Presently, an astounding 40% of lake Okeechobee is covered with cynaobacteria -- which is essentially 'Red Tide food' -- according to a report on the Palm Beach Post. Since the beginning of June, the Army Corps of Engineers has been releasing over a billion gallons of green slime contaminated lake water daily into the Caloosahatchee river which makes it directly into the Gulf, feeding the Red Tide blooms.
None of this would have to happen if it were not for the water management practices that have diverted the natural flow of water from Okeechobee, as depicted below:
What Can Be Done
To combat the algal blooms near shore in Florida we must first shake off the widespread denial and admit the scientifically proven fact that algal blooms are the result of land based activities (man made pollution of organic nitrogen) from sewage spills septic tanks leaks, overuse of organic nitrogen from manure on lawns, and agricultural runoff from sources like lake Okeechobee.
All of this we can abate if we have the will.
Please share this article and contact those in positions of influence to compel them to read the science discussed here.
Furthermore, please learn more below about the very serious heatlh issues associated with red tide exposure which is greatly minimized by those who are committed to covering up both the causes and extent of the problem.
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)
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.
How Red Tide Adversely Affects Human Health
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:
Bilateral Mastoiditis (infection of the mastoid bone behind the ear)
You can read the rest of the report here: The Truth About Red Tide's Manmade Causes and Health Effects
Also, to learn more about the highly toxic effects of cyanobacteria bloom exposures, read the article Toxic Algae: How Poor Wastewater Management And Bad Agricultural Practices Slimed Florida.
Follow APP Advocate Precautionary Principle who first alerted me to the research on how green slime feeds red tide.