Fish on Valium: A Multitude of Prescription Drugs Are Contaminating Florida’s Waterways and Marine Life

Fish and marine life off South Florida’s coast are ingesting high amounts of pharmaceuticals flushed down the drain or excreted in wastewater, because outdated treatment facilities are unable to detect and filter out the contaminants.

Results from a study by researchers at Florida International University’s Coastal Fisheries Research Lab have identified 58 different pharmaceuticals in 93 bonefish, sampled along a 200-mile stretch of South Florida’s coastline over a three-year period. In one case, the researchers found 16 different drugs in a single fish. 

The study has not yet been published, but Dr. Jennifer Rehage, lead researcher for the study and associate professor at the Institute of Water and Environment at Florida International University in Miami, said she and her co-authors planned to submit it to a peer-reviewed journal. 

She said they decided to share the research findings before publication because the bipartisan infrastructure bill passed by Congress in 2021 offered an opportunity to bring attention to key areas for investment, like the flaws in water treatment and regulation that allow pharmaceutical contamination.

Congress approved President Joe Biden’s $1.2 trillion infrastructure bill in November 2021. It provides more than $500 billion in federal funding for improving roads, bridges, water and energy systems over five years. Most of these investments will go to the states, which will determine which sectors would benefit. 

Dr. Duane De Freeze, a marine biologist and executive director of Indian River Lagoon National Estuary Program, called the study an original contribution to existing research because it looked at the presence of contaminants in bonefish, an “incredibly important recreational sport fish with very high economic value.” 

“When you look at the research over the last couple of decades,” he said, “whether it’s on Atlantic bottlenose dolphin, manatees and other species in Florida, what it’s building is a really strong case that we have toxicants and other emerging contaminants of concern that are getting through our wastewater systems.”  

He said previous studies in Florida have documented human antibiotics and some endocrine disruptors in wildlife. 

“So, it is not surprising that we would see some of these chemicals in the tissue or the organs of marine organisms,” he said.

Unregulated Contaminants

In Florida, Rehage said, one-third of households have septic tanks and two-thirds have sewer lines, and “conventional wastewater treatment in Florida and other parts of the United States does not remove pharmaceuticals.” 

“It’s in our drinking water. We also have it in our fish that we consume,” Rehage said, adding, “The risk is very small because concentrations are very small. But no one knows what it means for us to be exposed over our lifetimes to so many pharmaceuticals.” 

Rehage noted that there are no regulations governing the production or disposal of pharmaceuticals. “So, they’re not considered a contaminant.”

Alexandra Kuchta, a spokesperson for the Florida Department of Environmental Protection, said that the department worked jointly with state health, agriculture and wildlife conservation officials “to determine if environmental chemicals are present in fish from Florida waters.” 

Kuchta called pharmaceutical contaminants “an emerging issue,” and said that the environmental protection department ”looks forward to working with stakeholders as new science becomes available.”

In the new study, blood tests and tissue analysis were used to screen the fish. The prescription pharmaceuticals detected included antidepressants, antibiotics, heart medications, blood pressure medications and pain relievers. The same contaminants were also found in crab, shrimp and other small sea animals that the bonefish feed on, as well as in water and sediment. 

The study began in 2018 and was conducted by a team of Florida International University scientists in partnership with Sweden’s Umeå University and the University of Agricultural Sciences. The researchers recorded an average of seven pharmaceuticals per fish analyzed in South Florida waters, and the contaminants were detected both in fish taken from water near urban centers and from remote locations. 

Contaminants were also found in 43 bonefish tested in waters near the Caribbean, Bahamas, Puerto Rico, Mexico and Belize. 

The researchers found the highest number of contaminants in one fish taken from Biscayne Bay. The pharmaceuticals detected in the fish included eight different antidepressants, at concentrations equal to as much as 300 times the amount prescribed for humans. The study also found concentrations of Parkinson’s drugs, antifungal drugs, stomach medications and opiates in the fish.  

“The levels in bonefish blood and tissue were high enough to have biological effects,” the researchers wrote, in a summary of  their findings. A Miami-based nonprofit, the Bonefish & Tarpon Trust, funded the research. The study is the latest in a growing body of research over the last three decades that has documented the presence of pharmaceuticals, steroid hormones, and personal care products in Florida’s coastal waters. 

Aaron Adam, director of science and conservation at the bonefish trust, called the study’s methodology rigorous and said the findings support the conclusions of previous research.

Sources of Contamination

One earlier study, published in February 2021, found that heavily populated areas of South Florida that were not served by municipal wastewater collection could end up with contaminants reaching coastal waters and wetlands through runoff or groundwater flow.

South Florida is host to a diverse range of protected ecosystems, including wetlands and coral reefs situated close to large metropolitan cities. 

“Global pharmaceutical production is skyrocketing, compared to other things we care about such as human population growth, or CO2 emissions,” Rehage said. She said the contaminants come in large part from the prescription drugs people ingest and excrete, with effluent traveling through a septic system or sewer line to the ocean or other bodies of water. 

These waterborne chemicals pose a significant threat to the flats fishery, an important component of Florida’s recreational saltwater fishery, which generates more than $9 billion annually and supports nearly 90,000 jobs, Adam said. 

He said that most of the chemical contamination seems to come from people taking prescription medications. “Only a portion of the drugs that people take are absorbed by the body. We excrete the rest that gets sent to the wastewater treatment system,” Adam said, adding that to his knowledge, there were no regulations governing the disposal of pharmaceuticals in wastewater. 

He said there was also a concern that pharmaceuticals — as well as nutrients in runoff from stormwater, agricultural lands or treatment plants — were entering the aquifer, the main source of drinking water for much of the state.

The chemicals enter the groundwater and coastal waters through various sources of wastewater discharge. Nutrients in the water can feed toxic algae blooms or Red Tide, a type of harmful algal bloom. The blooms are caused by high concentrations of a plant-like microscopic organism known as Karenia brevis, which feeds on the nutrients.

A recent report by the state’s task force on harmful algae blooms estimated “total losses of nearly $1 billion in revenue and an additional loss of $178 million in tax revenue in 23 Gulf coast counties” as a result of a prolonged Red Tide that lasted from 2017 to 2019. 

Contamination of fish comes from the same wastewater discharge sources as the nutrients. 

“We need immediate improvement in infrastructure that we and others are pushing for, not only to remove more nutrients, but also removing these pharmaceutical contaminants,” Adam said.

Targeting the Problem

In his early days in office, Gov. Ron DeSantis said he would prioritize Florida’s environment and water quality improvement by funding programs and enabling legislation. His tenure has seen the passage of the 2020 Clean Waterways Act and the establishment of a wastewater grant program. 

Christina Pushaw, the governor’s spokesperson, said the governor’s environment-related budget recommendations for next fiscal year includes $195 million for targeted water quality improvements. 

“Most of this funding will support critical infrastructure and projects to provide advanced wastewater treatment and to upgrade wastewater facilities, Pushaw said. “These investments are crucial to achieve impactful nutrient reduction goals in key water bodies across the state.” 

But advocates say that the state’s measures so far have stopped short of requiring private housing developers to invest in better treatment facilities or implementing better regulatory safeguards.

The presence of pharmaceuticals and other chemicals in Florida’s coastal waters compounds the adverse impact on the ecosystem of the excess nutrients that feed the harmful algal blooms. According to the Environmental Protection Agency, there is also strong evidence that exposure to a variety of synthetic chemicals known as endocrine disruptors adversely affects the reproductive behavior of fish and other marine animals.   

Endocrine disruptors can have an impact on humans and wildlife — including reproduction, development and immune systems, according to the National Institute of Environmental Health Sciences. A wide variety of substances, including pharmaceuticals and pesticides, can cause endocrine disruption.

Studies have found that pharmaceuticals that contain or mimic hormones, like birth control pills, have caused male fish to develop ovaries. 

Anti-anxiety drugs like Valium can cause fish to become more active, less social and to take more risks, according to the bonefish contamination study, making them more likely to be eaten by predators. The overall effect, the Florida International researchers said, is lower survival rates for the fish. 

The effects of the pharmaceuticals in the water on fish are likely permanent, because changes in brain chemistry follow exposure, the researchers said. “This is similar to how opioids, like Oxy, affect humans who get addicted to them,” they wrote in their report of the research. So if pharmaceuticals make a fish more skittish, the fish will always be skittish, even if the pharmaceuticals are removed, the researchers said in reporting the research. 

According to the Centers for Disease Control and Prevention, an analysis of prescription rates from 2015 to 2016 found that in any 30-day period, 45.8 percent of the American population had been prescribed a drug. The most commonly prescribed drugs for 12 to 19-year-olds were central nervous system stimulants. For 20 to 59-year-olds, antidepressants were most commonly prescribed.

Despite the fact that so many Americans have for decades consumed pharmaceuticals or  flushed the drugs down the drain, there are no regulatory controls in place to check their discharge into the environment or to monitor the risk they may pose to ecosystems and human populations.   

In January 2010, the Florida-based Center for Biological Diversity petitioned the EPA to establish water quality criteria under the Clean Water Act for endocrine disrupting chemicals. 

The center argued that the science indicated that endocrine disrupting chemicals persisted in bodies of water throughout the nation, brought in largely through runoff and treated wastewater discharges. The chemicals, the biological diversity center said, affect “the biological, chemical, and physical integrity of our water, and are having profound effects on the flora and fauna that rely on them.” 

In its September 2011 response to the petition, the EPA denied the request to establish or revise the water quality criteria provided by the Clean Water Act.  

Jaclyn Lopez, Florida director of the biological diversity center, said the pharmaceuticals are getting into the water “because we are directly discharging our treated wastewater into our surface waters, where we then expect to have fishable, swimmable waters, and in some cases, drinkable waters.” She said that until the EPA establishes water quality criteria for endocrine disrupting chemicals, those activities will remain unregulated. 

Calling it an unfortunate situation, Glenn Compton, chairperson of the environmental nonprofit Manasota-88, said the problem of pharmaceutical contamination has been known for about 30 years but that “little to nothing has been done to address the monitoring of pharmaceuticals in our wastewater supply. And that certainly needs to change.”  

“I don’t see things getting better in the near future,” Compton said. “We need changes at the state level, with policymakers that truly understand the importance of the water quality in the state of Florida and the necessary things that need to be done.