Lake Okeechobee, Florida CNN  — 

On any given day, helicopters and an armada of airboats fan out across Florida’s fresh waters to spray tank after tank of poison. Without the millions of gallons of herbicide poured into rivers and lakes, officials say, the state would be choked with weeds.

But a growing chorus of fishermen and hunters, naturalists and activists disagree.

They are convinced that what started as sensible navigation and flood control has turned into a million-dollar-a-month chemical addiction that is killing Florida’s natural state.

To gather evidence, a home builder and angler named Mike Knepper has spent over a year chasing spray boats with a camera drone – a modern-day David taking aim at a giant.

When he captures a state contractor spraying weed killer on live birds or baby alligators, or illegally blowing herbicide across wetlands with the fan of an airboat, the videos become stones in his Facebook sling.

His Goliath is Florida’s Fish and Wildlife Conservation Commission, better known as the FWC, which bats away the criticism.

Herbicide is sprayed from an air boat on Lake Okeechobee, Florida.

“The FWC takes the mistreatment of wildlife seriously and our contractors are thoroughly trained and monitored,” wrote Kipp Frohlich, director at the FWC’s Division of Habitat and Species Conservation, on Facebook. He was responding to a September video, narrated by Knepper, which shows contractors on Lake Kissimmee hosing herbicide toward wildlife, including a snail kite – an endangered bird of prey.

Either by sloppy chance or cruel intent, some clips show the plume of weed killer following birds as they flee but, according to the FWC, “The video in question does not show any inappropriate behavior. Wildlife was not targeted or harmed … the treatment will benefit native plants and animals.”

But more viral videos only brought more scrutiny, controversy and eventually a rare concession from the FWC that the herbicide program has gone too far.

“Despite what you hear on social media, we care about the health of the fish and the wildlife and the ecosystems,” said Eric Sutton, the FWC’s executive director during a public meeting in December. “We also believe that we would like to see a future that doesn’t have to rely upon herbicides.”

While announcing an open call for new ideas, Sutton described a plan to keep a closer eye on contractors by putting GPS-enabled sensors on spray nozzles to record the amount and location of every squirt of poison. “Because we’ve heard accusations that people are just dumping it,” Sutton said. “Well, we’re going to hold them accountable.”

Mike Knepper uses a drone and camera to track spraying on Florida's lakes.

But what started as public outcry over a few sprayed animals has now exploded into a statewide debate over a mounting environmental crisis and how a reliance on weed killers could be a major piece in Florida’s toxic puzzle. As the FWC focuses on the alleged misuse of herbicides, opponents are pointing out the damage the spraying does when it is used exactly as planned.

While fast-growing invasive plants outcompete some native species and threaten some waterways, the lush aquatic life serves as the liver and kidneys of Florida’s circulatory system. Plants like water hyacinth and water lettuce can clog navigation channels and tangle in propellers, but they are also natural filters that help clean all the pollution flowing out of farms, golf courses and neighborhoods.

The Florida Fish and Wildlife Conservation Commission takes action against fast-growing plants that can clog waterways.

Since 2013, hundreds of square miles of these wetland filters have been sprayed with dozens of different herbicides at a cost of over $100 million.

“All the water that comes out of this creek and out of that canal used to be filtered before it entered the lake by seven miles of submerged grass,” says pro fisherman Brandon Medlock as he motors his bass boat across Lake Okeechobee. “That grass is now gone.”

Fisherman Scott Wilson said seeing the herbicide destruction on Lake Kissimmee left him a broken man.

Beside him is retired pastor and fishing captain Scott Wilson who squeezes his eyes tight with emotion as he describes the changes. “When I saw Grassy Island on Lake Kissimmee disappear, I was in tears, sir. I was broken. It was one of the most phenomenal fisheries on this planet.”

They are among the critics who argue that by poisoning these plants and letting them sink to the bottom to rot, the FWC is only adding to the thick layer of fertilized muck that has been building in Florida’s wetlands for generations.

When pollution-rich flood water is released into the sea or when hurricanes churn and spread that muck layer across the Gulf of Mexico, scientists believe it serves as a powerful booster shot for naturally occurring toxic algae blooms, including the devastating red tide.

Dead sea life litters the ocean off Florida's Sanibel Island during a red tide in 2018.

“Between our use of nutrients and the development of Florida, warming seas and climate change are we poking the bear?” asks Mike Parsons, a marine scientist and red tide specialist at Florida Gulf Coast University.

He explains that human activity does not start a red tide – they’ve been recorded in the Gulf for centuries – but modern blooms are becoming longer and more destructive thanks to all the man-made runoff coming out of Florida and down the Mississippi.

“We know human-contributed nutrients can affect a coastal red tide, and we must expand our data and monitoring efforts to confirm whether and how they did in each specific case,” reads the website of Mote Marine Laboratory, an independent research group working with the FWC.

In 2017, a few months after Hurricane Irma blew across lakes like Kissimmee and Okeechobee, hundreds of tons of dead fish, sea turtles, dolphins and manatees began washing up on Florida beaches. As the bloom lingered for 16 months, the state lost millions in tourism and real estate deals. Red tide kills fish and animals that wash up on beaches and can cause illness in humans too. People have been warned not to swim in water affected by a red tide, eat seafood from it, or breathe the air near it.

Dead marine animals, killed by the red tide, are cleared off Florida beaches in 2018.

“I mean, the only possible way of fixing it is more Mother Nature, especially wetlands, cleaning the water,” said William Mitsch, a specialist in freshwater ecology at Florida Gulf Coast University. But as the population of Florida grows by an average of 38 people an hour, a prescription for more wilderness and less development is a heavy political lift.

While there are biologists on the FWC staff, it is led by well-connected political appointees. Chosen by the governor, the seven-person commission is filled with developers, financiers, the wife of a former commissioner and the golf course designing son of Jack Nicklaus, but no scientists or conservationists.

In August, Governor Ron DeSantis revived Florida’s Red Tide Task Force after 15 years of dormancy and filled it with 11 scientists and specialists as the legislature promised nearly $5 million in funding. Whether they report a definitive link between toxic algae blooms and Florida’s spraying policies remains to be seen. In the meantime, public pressure fueled by Knepper’s videos has led to a moment of reckoning.

Mechanical harvesters can cut weeds without the need for herbicides.

“We have a lot of stakeholders who are complaining that we are doing it wrong,” said FWC Commissioner Rodney Barreto in December’s call for poison-free ideas. “OK, then tell us how to do it better, OK? If you had a million dollars, how would you do it?”

“The first thing we have to do is just turn off the nozzles,” says Knepper between drone flights. “That doesn’t cost anything!”

He argues that mechanical weed harvesters could handle navigation and flood control demands but big lakes like Okeechobee – with few lakeside homeowners and water-skiers – could largely grow wild with no ill effects.

Brandon Medlock drives his boat on Lake Okeechobee, where he says submerged grass used to help filter the water.

“We can’t boot the 21 million people out of Florida. OK?” Knepper says, voice high with emotion. “We not going to stop growing sugar or mining for phosphorus fertilizer. But the one thing that we can do is stop spraying and killing the filter! So let’s just do that!”

The FWC declined five CNN requests for interviews or comment and has yet to say what new ideas they received or when they might be tested. While a brief spraying pause was enacted last year, the airboats and helicopters keep spraying for now.