Is Monsanto's Glyphosate Connected to Algal Blooms & Marine Life Losses?

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In this interview, Dr. Stephanie Seneff, MIT scientist and glyphosate expert answers questions from Zen Honeycutt about the relationship between glyphosate and algal blooms. 

Honeycutt: Dr. Seneff, millions of Americans are distraught by the marine life disaster in Florida. This is not the first time that toxic blue-green algae have plagued our waters. Two years ago EcoWatch published an article about glyphosate herbicides (sprayed around reservoirs and on nearby farms) being linked to toxic green algae in Lake Erie. You have been studying glyphosate for years now, how could glyphosate be connected to toxic blue-green algae? What is happening?

Seneff: It's very straightforward. The so-called blue-green "algae" are actually not algae but rather a type of primitive bacteria called "cyanobacteria." They have a special skill that is rare among all species to be able to fully metabolize glyphosate and use its phosphorus atom as a source of phosphorus. So they obtain a competitive advantage against other species in the presence of chronic glyphosate exposure.

There are a lot of sugar cane fields surrounding Lake Okeechobee in Central Florida, and they are being sprayed with glyphosate before harvest as a desiccant. There's also lots of glyphosate being used on those well-manicured lawns of multi-million dollar homes.

Honeycutt: So the blue-green algae are in response to the presence of glyphosate herbicides. Is it likely that the blue-green algae are caused by glyphosate herbicides or is the algae already there and glyphosate promotes the growth?

Seneff: Blue-green algae are always present in the mix, but without glyphosate, they don't grow to such huge concentrations compared to the competing flora.

Honeycutt: What function are the blue-green algae in the ecosystem? Could it be a way of balancing out the levels of toxins or is it simply an overgrowth like a virus?

Seneff: Interestingly, what happens when you expose a complex mix of microbial flora to a chemical toxin is that those that are most susceptible die out, and those that have resistance thrive. Despite all the damage that the cyanobacteria cause when they reach high concentrations, a huge benefit they offer is that they clear the glyphosate and eventually leave the water in a better state than it would be in if glyphosate were allowed to persist. They may also be able to bind to and remove toxic metals from the aquatic environment.

Honeycutt: Lake O in Florida is being drained into the ocean. Officials claim that the blue-green algae have nothing to do with the red tide. Do you believe this? How could the blue-green algae be contributing to the red tide?

Seneff: No, I don't believe this! Again, very straightforward. The blue-green algae (cyanobacteria) are able to convert free nitrogen from the air into nitrates. Thus, they cause an excess of nitrates in the water, in addition to those nitrates that come from excess run-off from nitrate-based fertilizers. The excess nitrates provide essential nutrients for the red algae (Karenia brevis), that then grow to large numbers offshore, causing the red tide. [NOTE: additionally, peer-reviewed, published research shows cynobacteria can act as a nutrient source for Karena brevis. Learn more here.]

Honeycutt: In California, water officials have admitted to me that they spray Roundup around our water reservoirs for weed abatement. Then, when the blue-green algae grow, they spray copper to stop the growth of the algae. This is very concerning to me because copper is a known spermicide. It is even used as birth control in IUDs. High copper levels also have been found in children with autism. One would think we should avoid spraying copper into our waterways.

Seneff: I totally agree. These chemical-poison-based methods seem to cascade into much larger problems as one imbalance leads to another bad choice and eventually you end up with a toxic soup.

Honeycutt: How can officials and residents stop the growth of blue-green algae and red tide safely?

Seneff: For one, banning glyphosate would be a great start! Switching to renewable organic agriculture in the region would greatly curtail the toxic chemicals as well as reducing the nutrient run-off that's fueling the algae blooms. The homeowners should seek a solution for their yards that uses only natural methods to control weeds, including pulling them by hand.

Additional Information

Glyphosate has been studied to both shape dinoflagellate-associated bacterial community while also providing a nutrient source -- namely, phosphorous -- for algal growth. A paper published in 2017 in Frontiers in Microbiology titled, "Glyphosate Shapes a Dinoflagellate-Associated Bacterial Community While Supporting Algal Growth as Sole Phosphorus Source," revealed these relationships. 

Read the entire article here.

For more information on the relationship between nutrient pollution, cynobacteria, and Karena Brevis (Red Tide) outbreaks, consult the following articles: 



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