Fishermen and Scientists Probe Phosphate’s Connection to Florida Red Tides | Civil Eats

Fishermen and Scientists Probe Phosphate’s Connection to Florida Red Tides

Thousands of dead fish float in the Boca Ciega Bay located near the mouth of Madeira Beach, Florida, on July 21, 2021. (Photo credit: Octavio Jones/Getty Images)

As commercial fisherman Casey Streeter motors away from the shore off Matlacha in southwest Florida, the water is so shallow that the bright white, sandy bottom is visible through the teal water. The water has recovered from last year’s red tide, but the event—and its aftermath—still weigh heavy on Streeter’s mind.

“When we have a red tide we see the water turn orange and brown. It feels biblical, like end-of-times stuff. There is a white carpet of dead fish floating for 20-30 miles.”

Streeter is a grouper and snapper fisherman who also owns a shorefront restaurant and community-supported fishery. Over the last few years, along the mangrove shorelines of Florida’s Gulf Coast, he and other small-scale commercial fishermen have experienced some of the worst water conditions on record.

Red tide algal blooms occur every year, typically in the summer or early fall, but in recent years they have gotten worse, bringing more algae for longer periods of time and creating sizable hypoxic “dead zones” with little to no oxygen, suffocating sea life. The red tide event of 2017–2018 was particularly destructive and lasted for more than six months. It came back in 2021 and again lasted five months. Both events resulted in massive fish kills that released a putrid stench and toxic aerosols that caused respiratory irritation.

This winter, many fisheries and seagrass habitats have struggled to bounce back, as have the people who rely on those fisheries for their livelihoods. “The water is resilient, but it needs time to regenerate. We can’t keep having these red tide events every two or three years and expect small-scale fishermen to survive,” says Streeter.

“Our commercial fishery has been beat down. We’ve lost almost all our net fishermen, our stone crabbers are on the edge,” he shouts over the sound of the motor. “When you have a tornado or hurricane, the event happens, then the rebuild starts right away. With red tide events, it’s a long road back.”

Streeter and other fishermen in the region draw a connection between the red tide events and the pollution from nearby phosphate mines used for fertilizer production. But there is little to no scientific data that establishes clear causation between the two events. A recent study from the National Oceanic and Atmospheric Administration (NOAA) has drawn a clear link between red tide and hypoxia, however. The researchers found that hypoxia occurred concurrently with extreme red tides in 2005, 2014, and 2018.

Now, fishermen are also working with scientists on a data collection process that sets out to determine whether phosphate mines may be linked to red tide in hopes that it can help lawmakers at the state and federal level begin to regulate the fertilizer industry and prevent further damage to the ocean ecosystems.

“We live in a water state where we have this incredible blue economy, but somehow a handful of mining operations are destroying it,” Streeter says. “We can’t wait until a major phosphate mine fails to address the problem.”

Mining for Fertilizer

Florida is currently home to nine active phosphate mine sites and 18 that are no longer in operation but may still pose an environmental hazard.

“A steady domestic supply of Florida-made phosphate ensures our country’s food security and well-paying American jobs,” is how the trade group Florida Phosphate Council describes its role; the group didn’t respond to a request for comment for this story.

Phosphate rock requires processing before it can be used in fertilizer in the form of phosphoric acid. The U.S. Environmental Protection Agency estimates that for every ton of phosphoric acid the mines create, it makes 5.2 tons of a byproduct called phosphogypsum. Phosphogypsum is often stored in open liquid retention ponds that can become unstable under heavy rainfall.

In one of Florida’s most recent environmental disasters, Manatee County declared a state of emergency in April 2021 and evacuated hundreds of families from the Tampa Bay area when a phosphogypsum stack at the former Piney Point fertilizer plant neared collapse. To relieve pressure, the Florida Department of Environmental Protection (DEP) allowed 215 million gallons of nutrient-rich industrial wastewater—and a year’s worth of nitrogen—to be released into the Tampa Bay estuary at that time.

That was just the latest incident at Piney Point, an abandoned phosphate plant and mine with a history of environmental and public health violations. In 2012, Piney Point’s owners, HKR Holding Group, filed for Chapter 11 bankruptcy, leaving the state to pay for remediation efforts estimated at more than $46 million. There have also been many other examples of phosphate mines causing severe environmental pollution.

Some advocates point to the fact that phosphate byproduct pollution increases nutrients in the water adding to the intensity of algal blooms. Phosphorus, among other nutrients, feeds Karenia brevis, the algae that causes red tide. But because Karenia brevis is found naturally throughout the Gulf of Mexico, most marine scientists are hesitant to attribute causation to phosphate wastewater mismanagement. Tom Frazer, the former Chief Science Officer for the state of Florida, points to excess nutrients from septic systems as well as agriculture and lawn care fertilizer run-off.

And yet, after the Piney Point wastewater was released into Tampa Bay, ocean currents carried along the coast of Southwest Florida. In July, the area experienced one of its worst algal blooms in years, leading to 800 tons of dead sea life washing onshore in Pinellas County alone.

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Back out on the water, Streeter’s boat stops as he and the captain, John Mertz, prepare to take a water sample to measure salinity, temperature, phytoplankton, and oxygen saturation. The results are sent directly to a database with NOAA as part of a partnership with Florida Commercial Watermen Conservation (FCWC), the nonprofit Streeter founded in 2018.

Streeter is especially invested in learning more about the role of phosphate mining in the recent red tide pollution because he and his fellow smaller-scale fishermen stand to bear the brunt of the problem. While larger, enterprise-scale fishing companies can absorb higher fuel costs and travel farther offshore with larger boats, smaller operations often stay closer to shore and must contend with restrictive fishing quotas. For them, the cost of doing business is already so high that shrinking catch numbers can pose an existential threat.

“The goal with FCWC is to protect our waters here and create a blueprint for recovery in other areas,” says Streeter. For the scientists he’s working with, it’s also to gather data on the role of the phosphate mines. By utilizing the fishermen who are already in the areas of concern for data collection, scientists can triangulate causation more effectively.

A gap between real-time data and the academic resources that can steer policy inspired the idea to enlist fishermen, who have the holistic knowledge of the ocean, as data collectors, says Chris Kelble, director of the Ocean Chemistry and Ecosystems Division at NOAA’s Atlantic Oceanographic and Meteorological Laboratory.

“Casey volunteered for a research cruise with me. The idea for the nonprofit stemmed from us sitting on the deck of the boat talking one night in between stations where we were taking water samples. He was instrumental in helping guide where to sample, because he knew exactly where the worst places were,” Kelble says. “Our goal this spring is to be able to communicate and let folks know about the likelihood of there being significant hypoxia. If there are excess nutrients coming off the land, this promotes red tide.”

FCWC is composed of half a dozen local volunteers and fishermen, in addition to Streeter. “We have mostly been focusing our testing in our immediate areas of southwest Florida,” he says, “but we did have a boat test off of Tampa during the red tide last year and as far north as Panama City. We would like to grow this program to all regions of the Gulf of Mexico.”

“NOAA doesn’t have the specific jurisdictional authority in coastal waters in relation to land-based sources of pollution. That lies within the state in partnership with the state Environmental Protection Agency,” Kelble says. “But we do collect data in coastal areas that will be used by those agencies to inform their decision-making.” Their hope is for their data to get picked up by the regulatory authorities—“the DEPs and EPAs of the world.”

In October of 2021, Kelble began working with Jordan Logarbo, a science policy fellow in the Gulf Research Program of the National Academies of Sciences, Engineering, and Medicine, to support the policy-level change that FWCW seeks to create. Following the Deepwater Horizon oil spill in 2010, the NAS created post-graduate science policy fellowships to provide opportunities for fellows to work with scientists who interface with policy on how to get more science into policy making.

“Because I am operating independently, this means that I can be a bridge between agencies,” says Logarbo.

While Logarbo’s policy fellowship work is focused on Florida fisheries, she draws a connection to environmental issues in her home state of Louisiana, “Every year at the delta, we get a giant hypoxic zone. Only 2 percent of Louisiana runoff contributes to this. Almost all of it is coming from agricultural runoff from the upper watershed.” NOAA estimates that the Gulf of Mexico dead zone costs the U.S. seafood and tourism industries $82 million per year.

Logarbo points to the fact that phosphorus and nitrogen are the most significant contributors to aquatic dead zones and sees the two crises as deeply connected. “The agricultural phosphate inputs that are contributing to the hypoxic zone in Louisiana are being mined in Florida, trucked up to the Midwest, and coming right back downstream.”

Informing a Critical Response

Nitrogen, phosphorus, and potassium are the “Big Three” elements—often referred to as NPK for their chemical symbols—used in synthetic fertilizers to promote plant growth. Commodity farmers often work within razor-slim margins in an economic model that is based on global markets, making investment into reducing fertilizer use and improving soil through regenerative practices unfeasible for many.

The upcoming farm bill is the only mechanism to expand funding for agriculture conservation programs, which are aimed, in part, at reducing nutrient runoff. By gathering data around the damage facing coastal ecosystems, Kelble and Streeter are hoping to create political urgency in connecting the dots between dependence on fertilizer among land-based farmers and the resulting impacts on the ocean.

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“What we’re seeing in our data, and it’s true for most of the globe, is that when coastal pollution is increased, we lose habitat. We also see hypoxic areas. Both this loss of habitat and oxygen negatively impact coastal fisheries populations,” Kelble says.

Streeter and others hope to see federal agencies create tighter regulations on mining operations and federal oversight of state waters; federal water begins at 9 miles offshore, while coastal waters are governed by the state.

In 2019, Florida Governor Ron DeSantis appointed the Red Tide Task Force to address ongoing red tide concerns. The task force report released in January 2022 estimated losses of nearly $1 billion in revenue and $178 million in tax revenue in 23 Gulf Coast counties. The report made broad recommendations for increased water monitoring, communication of red tide events to affected communities, and actions to reduce excess nutrient loading into waterways.

In December, drilling began on a deep injection well that will store Piney Point’s wastewater as a solution to the unstable phosphogypsum stack, according to the plan to close the facility by 2024. The porous nature of the limestone bedrock—which is historically prone to sinkholes—troubles advocates.

“There is fairly significant groundwater movement and groundwater exchange that happens in this limestone. It’s Swiss cheese, essentially,” says Kelble. “Anything that is so nutrient-rich in Florida should be put on trucks and taken out of state. This whole system is built on having clean clear water to support sea grasses, corals, and sponges. It is critical that we maintain that and not risk that in any way.”

In October, Florida Agriculture Commissioner Nikki Fried wrote a formal comment to the Florida EPA urging it not to approve the deep well permit. She cited concerns of groundwater contamination that would impact farmers and the blue economy, suggesting instead to move hazardous wastewater to a safer location.

“With phosphogypsum wastewater breaches like the spill in Tampa, our mullet fishermen take the largest hit,” says Streeter of the economic fallout. “With an event like that it’s hard to measure the immediate economic losses because not only do they take a hit that year, but future spawning potential is impacted.”

He and others in Florida say they want to see their ocean home prioritized and valued on a level that is on par with land-based agriculture. “What is the [fertilizer] industry really worth compared to what we lose from our fisheries and tourism? What is the greater cost to the state of Florida?” Streeter says. “If we don’t end phosphate mining, we could lose everything that people come here for.”

Jonnah Perkins is a farmer and writer based in southwest Wisconsin. After over a decade working in agriculture at her family's CSA farm and organic seed potato production, she has gained access and insight into the power of food to shape movements, cultures and ecological solutions. Jonnah's work focuses on the intersection of food, agriculture, climate change, and conservation. You'll find Jonnah reporting stories in the field where natural resource management and food systems collide. Read more >

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