New study confirms long-assumed link between red tide and Lake O discharges

May 3, 2022

It’s official, anthropogenic forcing is a key component of coastal K. brevis bloom dynamics. Translation: human activity on land has a significant effect on red tide blooms in our waters. That’s according to a recent study completed by the University of Florida Center for Coastal Solutions with help from Sanibel-Captiva Conservation Foundation.

The study, titled Nitrogen-enriched discharges from a highly managed watershed intensify red tide (Karenia brevis) blooms in southwest Florida, analyzed the influence of Lake Okeechobee discharges on red tide blooms near Charlotte Harbor and the Caloosahatchee River Estuary between 2012 and 2021.

The science finally supports common sense

Not surprisingly, the study concluded that the nutrient-enriched lake discharges intensify red tide blooms—they make them worse. (Red tide is a marine dinoflagellate that feeds on nutrients, like Nitrogen, and can take advantage of excess nutrients in the water to multiply.) Now, while this might not seem like revelatory information, the results of this study are actually a BIG deal.

That’s because, although many have long-assumed the connection between nutrient-polluted Lake O discharges and the supercharged red tide blooms that stain our waters, pollute the air, and kill literal tons of marine life, there has not been hard scientific data to support it. Recent research has suggested the connection, but as the study opens, “past correlation studies have failed to detect compelling evidence linking coastal blooms to watershed covariates indicative of anthropogenic [human] inputs.”

This research proves that direct link.

It provides the undeniable, scientific evidence necessary to demand a greater priority on fixing the broken system comprehensively—from reducing nutrient pollution to eliminating damaging lake discharges and completing cornerstone restoration projects like the EAA Reservoir.

photo by Jason Stemple
Pulling the plug on years of misleading propaganda

The study is also a big deal because special interests have long taken advantage of that information gap to spin misinformation, create doubt and spread propaganda contrary to the truth. They’ve spent millions on tactics to confuse the public, employing strategies similar to what Big Tobacco used in decades past to silence the notion that smoking can have damaging health effects.

A media release from U.S. Sugar during the 2018 water crisis titled, “The Facts on Florida Red Tide — It Is NOT Caused by Lake Okeechobee” strung together a series of half-truths, fallacies, and expert quotes taken out of context in order to serve their agenda and distance themselves from the environmental disaster that was unfolding.

photo by Jason Stemple

Special interests have often leaned into the fact that red tide is “naturally occurring” to distract the public from the worsening effect of the high-volume, nutrient-laden lake discharges.

And it’s true that red tide is naturally occurring. It’s not “caused” by the discharges, but the discharges sure can make blooms a lot worse, leading to a much greater degree of environmental and economic damage.

Think of it like a forest fire. Gasoline might not start the fire, but when you pour thousands of gallons of gas on the blaze, it will fuel the flames, spread the fire, and have a direct impact on the amount of damage incurred.

That’s what happens when we see those long-period, high-volume discharges released into a marine environment where red tide might be present. We’re basically dumping gasoline on a forest fire, and the consequences are usually catastrophic.

Now, this study finally proves that connection exists.

photo by Jason Stemple
What’s in the study?

If you thought the title of the study was a mouthful, you should try digesting all 15 pages of it. That’s something we wouldn’t wish upon our worst enemy, and you’d probably have to be an astrophysicist to understand most of it anyway.

Thankfully, the study includes a summary of the key findings and highlights. Let’s break those down, starting with that first one from earlier.

1. Anthropogenic forcing is a key component of coastal K. brevis bloom dynamics.

Translation: Human activity on land has a significant effect on red tide blooms in our waters. Harmful algal bloom (HAB) dynamics, like those of red tide, are incredibly complex and include a range of factors and influences. They have been the subject of much research in recent years in an effort to support the development of effective prevention and mitigation strategies, but mixed evidence from past studies has led to suggest only a plausible connection between human activity and red tide. This study concludes that human activity is a key factor.

2. Nonlinear time series methods reveal state-dependent causal connections.

Translation: Taking advantage of a wealth of red tide and watershed data from the past decade, the study reverse-engineered cause-and-effect relationships and linked red tide blooms to human activity.

3. Caloosahatchee River discharges and nitrogen inputs systematically intensify blooms.

Translation: Discharge volumes from the S-79 structure (Franklin Lock & Dam in the Caloosahatchee River) and the concentration of Nitrogen contained within those discharges are systematic drivers of red tide blooms. Those two factors can intensify red tide blooms, making them longer lasting, more widespread, and/or more concentrated.

4. Anthropogenic influence extends upstream to Lake Okeechobee and the Kissimmee basin.

Translation: That human factor and influence doesn’t start in the Caloosahatchee River Estuary. It begins in the Kissimmee River basin north of Lake Okeechobee and includes the lake. So, any nutrient pollution that flows into the Kissimmee basin or into Lake Okeechobee also contributes to the concentrations of nutrients in the river discharges, ultimately contributing to the human influence on red tide blooms.

5. Nutrient/hydrological management may mitigate bloom intensity and duration.

Translation: By reducing nutrient pollution and improving lake discharge operations, the study concludes there is opportunity to reduce the intensity and duration of red tide blooms.

photo by Jason Stemple
What to do next?

With this new information, policymakers and managers need to double down on developing and implementing strategies to manage the system better. This study finally makes the definitive connection between Lake Okeechobee discharges and red tide, so it’s time to do more about it.

The science has been settled for decades on how to alleviate the damaging discharges from Lake Okeechobee. By restoring the Everglades and optimizing Lake operations to flow more water south during the dry season, we can significantly reduce the amount of nitrogen discharged to Florida’s Gulf Coast, thereby reducing the fuel that red tide blooms can use to devastate our communities and economy.

Captains For Clean Water will continue to educate on and advocate for long-term solutions to the nutrient pollution and lake management issues that create this red-tide link. Be a part of progress—join us in advancing those solutions for our waters by becoming a member today.

It’s official, anthropogenic forcing is a key component of coastal K. brevis bloom dynamics. Translation: human activity on land has a significant effect on red tide blooms in our waters. That’s according to a recent study completed by the University of Florida Center for Coastal Solutions with help from Sanibel-Captiva Conservation Foundation.

The study, titled Nitrogen-enriched discharges from a highly managed watershed intensify red tide (Karenia brevis) blooms in southwest Florida, analyzed the influence of Lake Okeechobee discharges on red tide blooms near Charlotte Harbor and the Caloosahatchee River Estuary between 2012 and 2021.

The science finally supports common sense

Not surprisingly, the study concluded that the nutrient-enriched lake discharges intensify red tide blooms—they make them worse. (Red tide is a marine dinoflagellate that feeds on nutrients, like Nitrogen, and can take advantage of excess nutrients in the water to multiply.) Now, while this might not seem like revelatory information, the results of this study are actually a BIG deal.

That’s because, although many have long-assumed the connection between nutrient-polluted Lake O discharges and the supercharged red tide blooms that stain our waters, pollute the air, and kill literal tons of marine life, there has not been hard scientific data to support it. Recent research has suggested the connection, but as the study opens, “past correlation studies have failed to detect compelling evidence linking coastal blooms to watershed covariates indicative of anthropogenic [human] inputs.”

This research proves that direct link.

It provides the undeniable, scientific evidence necessary to demand a greater priority on fixing the broken system comprehensively—from reducing nutrient pollution to eliminating damaging lake discharges and completing cornerstone restoration projects like the EAA Reservoir.

photo by Jason Stemple
Pulling the plug on years of misleading propaganda

The study is also a big deal because special interests have long taken advantage of that information gap to spin misinformation, create doubt and spread propaganda contrary to the truth. They’ve spent millions on tactics to confuse the public, employing strategies similar to what Big Tobacco used in decades past to silence the notion that smoking can have damaging health effects.

A media release from U.S. Sugar during the 2018 water crisis titled, “The Facts on Florida Red Tide — It Is NOT Caused by Lake Okeechobee” strung together a series of half-truths, fallacies, and expert quotes taken out of context in order to serve their agenda and distance themselves from the environmental disaster that was unfolding.

photo by Jason Stemple

Special interests have often leaned into the fact that red tide is “naturally occurring” to distract the public from the worsening effect of the high-volume, nutrient-laden lake discharges.

And it’s true that red tide is naturally occurring. It’s not “caused” by the discharges, but the discharges sure can make blooms a lot worse, leading to a much greater degree of environmental and economic damage.

Think of it like a forest fire. Gasoline might not start the fire, but when you pour thousands of gallons of gas on the blaze, it will fuel the flames, spread the fire, and have a direct impact on the amount of damage incurred.

That’s what happens when we see those long-period, high-volume discharges released into a marine environment where red tide might be present. We’re basically dumping gasoline on a forest fire, and the consequences are usually catastrophic.

Now, this study finally proves that connection exists.

photo by Jason Stemple
What’s in the study?

If you thought the title of the study was a mouthful, you should try digesting all 15 pages of it. That’s something we wouldn’t wish upon our worst enemy, and you’d probably have to be an astrophysicist to understand most of it anyway.

Thankfully, the study includes a summary of the key findings and highlights. Let’s break those down, starting with that first one from earlier.

1. Anthropogenic forcing is a key component of coastal K. brevis bloom dynamics.

Translation: Human activity on land has a significant effect on red tide blooms in our waters. Harmful algal bloom (HAB) dynamics, like those of red tide, are incredibly complex and include a range of factors and influences. They have been the subject of much research in recent years in an effort to support the development of effective prevention and mitigation strategies, but mixed evidence from past studies has led to suggest only a plausible connection between human activity and red tide. This study concludes that human activity is a key factor.

2. Nonlinear time series methods reveal state-dependent causal connections.

Translation: Taking advantage of a wealth of red tide and watershed data from the past decade, the study reverse-engineered cause-and-effect relationships and linked red tide blooms to human activity.

3. Caloosahatchee River discharges and nitrogen inputs systematically intensify blooms.

Translation: Discharge volumes from the S-79 structure (Franklin Lock & Dam in the Caloosahatchee River) and the concentration of Nitrogen contained within those discharges are systematic drivers of red tide blooms. Those two factors can intensify red tide blooms, making them longer lasting, more widespread, and/or more concentrated.

4. Anthropogenic influence extends upstream to Lake Okeechobee and the Kissimmee basin.

Translation: That human factor and influence doesn’t start in the Caloosahatchee River Estuary. It begins in the Kissimmee River basin north of Lake Okeechobee and includes the lake. So, any nutrient pollution that flows into the Kissimmee basin or into Lake Okeechobee also contributes to the concentrations of nutrients in the river discharges, ultimately contributing to the human influence on red tide blooms.

5. Nutrient/hydrological management may mitigate bloom intensity and duration.

Translation: By reducing nutrient pollution and improving lake discharge operations, the study concludes there is opportunity to reduce the intensity and duration of red tide blooms.

photo by Jason Stemple
What to do next?

With this new information, policymakers and managers need to double down on developing and implementing strategies to manage the system better. This study finally makes the definitive connection between Lake Okeechobee discharges and red tide, so it’s time to do more about it.

The science has been settled for decades on how to alleviate the damaging discharges from Lake Okeechobee. By restoring the Everglades and optimizing Lake operations to flow more water south during the dry season, we can significantly reduce the amount of nitrogen discharged to Florida’s Gulf Coast, thereby reducing the fuel that red tide blooms can use to devastate our communities and economy.

Captains For Clean Water will continue to educate on and advocate for long-term solutions to the nutrient pollution and lake management issues that create this red-tide link. Be a part of progress—join us in advancing those solutions for our waters by becoming a member today.