Florida’s Red Tides Are Back- But A New Solution May Be On The Horizon

Red algal blooms produced by the dinoflagellate Karenia Brevis in the Gulf Coast. Image credit to Kai Schumann (https://www.scpr.org/programs/loh-down-on-science/2016/10/24/14511/).

It’s that time of year again- the time when Floridians must throw on their face masks and turn on their fans in response to yet another round of the harmful algal blooms known as “red tide”.

Last year the phytoplankton responsible, Karenia brevis, made headlines after the organism’s seasonal blooms killed thousands of marine animals and saturated the air with neurotoxins. In just a few months, Florida businesses reported losses over $90 million (in data retrieved before the start of September). Doctors’ offices became crowded with patients suffering from respiratory distress and illness. Snowbirds halted plans to return to their tropical winter homes after the ocean waves turned the color of breakfast tea.

After a blissful (and much too short) period of recovery, K. Brevis’s return brings back fears of another period characterized by the draining of Florida’s economic, medical, and scientific resources.

In recently published reports, Florida Fish and Wildlife depicts several points of high and medium concentrations of red tide cells off the southern coast of Florida. These were confirmed by other monitoring organizations, including the Mote Marine Laboratory, located in Sarasota.

The release follows a recent surge of complaints from residents and tourists alike near the highly-populated Siesta Key and Lido Beaches. Last year’s record blooms choked the throats and pockets of coastal communities and businesses.

To understand why red tide has the effect that it does and what we can do about it, it is helpful to understand the phenomenon on a molecular level.

K. brevis is a single-celled dinoflagellate with a uniquely slow growth rate. What it lacks in speed it makes up for in its consumption, metabolizing a uniquely wide scale of organic and inorganic nutrients effectively. Other species of phytoplankton fail to compete in the nutrient-poor environments where K. brevis develops and thrives.

It is the general consensus of the scientific community that red tide blooms initiate offshore and are moved inshore via wind and sea currents. This defies a still-popular interpretation that coastal pollution is a causal factor of the toxic blooms. Once the blooms head toward coastal waters, the organisms will utilize any and all available pollutants, contributing to the frequency, intensity, and duration of the red tide. However, coastal pollution only exacerbates existing blooms.

The state has been working hard since the 1970s to improve the regulation of point-sources of pollution, or pollution from single identifiable sources (like an industrial smokestack or discharge from a wastewater treatment plant). Meanwhile, pollution from non-point sources, defined by more widespread and hard-to-distinguish origins (like the run-off from our golf courses, medians, and own front yards), have increased exponentially and show no sign of letting up.

The relationship is complex, but studies agree that coastal communities have become more susceptible to red tide takeovers due to the increase in pollutant production from surrounding human activity.

A prospective example of this is the past decades’ use of fertilizers with increasingly high urea concentrations. Studies from recent years link this shift in urea concentration to increased algal bloom incidence. This is not hard to believe, considering urea is a particular favorite in the diet of K. brevis.

Dedicated scientists have worked passionately to refine the techniques they use to observe and track the blooms, but many consider an effective and functional solution still far out of reach.

What if this isn’t the case?

There may be an organism who, like K. Brevis itself, has historically conquered treacherous ecological conditions and may be our most valuable ally in the fight against red tide.

The solution lies specifically in the infant science of mycorestoration, which employs nature’s most powerful superheroes- fungi.

There is no doubt that our planet’s natural systems of ecological function have been challenged as of late. Mycorestoration seeks to repair or restore these weakened environmental systems. Whether the damage is of manmade or more natural causes, fungi are indispensable resources for recovery- in fact, there is not a single organism on Earth that could survive without them.

Each individual mushroom species has a network of mycelium that is capable of degrading matter by secreting custom formulations of extracellular enzymes and acids. Mycelium is the fungal network that exists underground in connection to its fruiting bodies (the mushrooms we see sprouting up). Mycelium functions much like the human brain’s neurological networks and chemical dispersion, as it communicates similarly with other systems to adjust nutrient levels and reinstate environmental balance.

With unique sets of enzymes, mushrooms and their mycelium are able to accumulate and degenerate toxins, including those found in plastic, radioactive, and agricultural waste. While new to humans cognizance, the life-altering characteristics of fungi have been integral to our planet’s systems since its creation, and have facilitated the development of the landscape we know today.

It can sometimes be difficult to conceptualize how mushrooms could be practically utilized to help the environment. Paul Stamets, the father of modern mycology (the study of fungi), includes in his writings an inspiring anecdote which illustrates the real-world application of mycorestorative techniques. Stamets describes how he personally reduced fecal coliforms a hundred-fold in a single year by installing a perimeter of mushroom-inoculated wood chip beds on his property.

“I bought a small waterfront farm in Skookum Inlet, Washington… At that time, most of the septic systems in the area were primitive cedar barrels, pits, or poorly constructed drain fields. Fecal coliform pollution directly threatened the shellfish industry on the inlet. The livestock on my property was just one source of bacteria jeopardizing these family businesses… But just 1 year after I had installed my beds of mycelium, before I had even repaired my septic system, analysis of my outflowing water showed dramatic improvement: a hundred-fold drop in coliform levels despite the fact I had more than doubled my population of farm animals. The anomalous decline in fecal coliforms surprised the water quality inspectors monitoring the inlet… I explained to the inspectors that the contaminated water seeped from our livestock pasture, entered the mycofilter, and fed the myceliated wood matrix with nutrients and bacteria. The water that exited our wood chip bed was largely cleansed of bacteria, which had been consumed by the mycelium of the garden giant…”

Stamets’ experiment attracted the attention of the Environmental Protection Agency (EPA), as well as the U.S Department of Defense- pretty good for a mycologist!

But how exactly can we use these techniques in the prevention, control, and mitigation of red tide?

Concerning prevention, measures must be taken to achieve ecological balance by controlling sources of non point pollution and balancing nutrient loads near the shore to improve water quality throughout the watershed.

Most initiatives up until now have centered around governmental regulation of maximum daily nutrient loads and permit allowances. However, mycofiltration techniques have much to offer and can provide a solution for the largest source of non-point pollution- agriculture as we know it.

Agricultural run-off deposits nitrogen and phosphorus directly into our watersheds (along with other agricultural by-products, including zinc and copper). There are catalogues of mushroom species identified to have specific antimicrobial and degenerative effects on corresponding pathogens and toxins, including those found in the waste produced by land usage. A variety of techniques, similar to those conducted by Stamets, have proven effective for the processing of harmful substances out of the watershed. Tube encasements of straw inoculated with oyster mushroom mycelium, called MycoBooms, float in saltwater and can be placed wherever pollutants are entering the watershed (from sewage pipes to entire inlets), processing harmful substances and releasing enzymes which encourage biodiversity and balance in an ecosystem.

Regarding the removal of red tide from the water column, Frank Alcock, the former Director of Marine Policy at the Mote Marine Laboratory, has established a criteria to determine the practicality of potential techniques for application. In his assessment, he proposes five key questions which must be considered in the assumption of a technical solution.

  1. Does a considered technology effectively kill, contain or neutralize K. brevis cells and/or the brevetoxins they produce?
  2. Does the considered technology pose less of an ecological risk than letting the bloom run its course?
  3. Is it logistically feasible to deploy a considered technology in a manner that will render it effective? … Two logistical factors are especially important. One is the total biomass of an active red tide bloom and the space it covers… The other is the importance of deploying the considered technology at sufficient concentrations throughout the water column.
  4. Is the cost of deploying a control technology appropriately considered in relation to the potential economic losses that the control technology is seeking to prevent?
  5. Has public opinion been taken into consideration? While related to actual ecological risks and economic costs, public perception toward the use of a particular control technology remains a factor that affects policy decisions.

In order to consider mycoremediative practices as a solution to red tide blooms they must meet these requirements.

Many are unsure what scientists are already doing to combat red tide. For now, flocculation is one of the main focuses of research in the control of red tide, and for good reason. Flocculation is the process by which a substance is added to a solution to create a “floc”, which binds with particles to form clumps. Flocculation using clay is regarded as one of the only control techniques with a success record in real-world applications. Unfortunately, there are still many hurdles to overcome before it can be considered viable. In the perfect scenario, the algal cells would bind with the clay and drift to the sea floor, where they would become trapped and die. But a slurry concentration too low could result in ineffectiveness, and a dosage too high could rupture cells, releasing brevetoxins into the water channel, harming marine life in the area. Even further, some of the most effective clay types contain heavy metals and radionuclides which would negatively alter the environmental system .

A visual representation of clay flocculation, one of the focuses of local scientists’ research into red tide mitigation. Image by Jack Cook, of the Woods Hole Oceanographic Institute.

Flocculation involves a gathering and accumulation of particles, a job naturally familiar to fungi. Where methods of traditional clay flocculation fail outside of the laboratory, mushrooms and their mycelium offer environmentally-friendly and cost effective alternatives.

In 2007, the accumulating abilities of fungi were tested (and proven) when oyster mushrooms were used to soak up and break down 58,000 gallons of diesel fuel resting off the San Francisco shoreline rapidly and effectively.

In another real-world application, after the deployment of stored nerve gas agents during the Iran-Iraq War in 1988, the world realized that the neutralization of neurotoxins should be a priority in the handling and disposing of chemical weapons. In response, research teams found that certain strains of mushroom species could adapt to digest the toxins of chemical and biological weapons.

Having analyzed the research and literature available on the causes and consequences of red tide, I suspect that the capacities of mycoremediation extend far past their current applications, and might be able to fill in the blanks where traditional techniques are limited. Mycoremediation seeks to balance the ecosystem from the bottom-up, and innovative practical applications are not only historically successful, but often low-cost.

As ecosystems change, fungi are able to modify themselves in order to remain the engineers and balancers of the nutrient cycle and the ecosystem overall. Could there be a mushroom species that exists with the ability to consume or prevent the neurotoxic emissions of K. brevis? How could the marine landscape incorporate mycotechnology in a way that facilitates the healthy development of the ecosystem, and the protection of its inhabitants?

In the wake of the re-emergence of local blooms, citizens and politicians alike must ask these questions, and acknowledge the battles occurring in our environment, to support the ongoing science and innovation behind means of prevention, control, and mitigation of red tides.

Current undergraduate student in Environmental Studies and Religion. Equally passionate about American Transcendentalist philosophy and the Grateful Dead.

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