A recently released study builds on previous research and leaves no doubt that Florida’s fish have a drug problem.
Local anglers and researchers from Florida International University (FIU) joined throngs of recreational fishers last summer in search of the ever-popular red drum – commonly known as redfish. The goal was to test blood samples for 94 pharmaceutical contaminants.
All 15 fish caught around Tampa Bay tested positive for a heart medication. Only seven of the 113 sampled throughout nine Florida estuaries were clean.
The Miami-based Bonefish and Tarpon Trust (BTT) commissioned the study as part of its extensive research into the issue. Dr. Aaron Adams, director of science and conservation for the BTT, said that if the drugs are in redfish, “they are certainly in every other organism in our coastal waters. So, yeah, that’s a big concern.”
“We have a coastal fish that is exposed to pharmaceuticals that we know will probably cause problems with feeding activity, migratory behavior, survival and reproduction,” Adams elaborated. “In addition, a number of the pharmaceuticals detected, we have absolutely no idea what the effects might be.”
The redfish research follows a 2022 study by the same group that found a plethora of pharmaceutical contaminants in all bonefish sampled from Biscayne Bay and the Florida Keys. Dr. Jennifer Rehage, a fish ecologist from FIU, led both initiatives.
Researchers found 58 various drugs in the bonefish, and each averaged seven. One contained 17 different pharmaceuticals.
While the local redfish sampled did not contain those concentrations, the species is critical to Florida’s $13.9 billion recreational fishery. The latest report stated the findings pose “a significant threat” to an industry that “directly supports more than 120,000 jobs.”
Adams said the redfish study shows the problem extends far beyond Miami and bonefish.
On average, researchers detected 2.1 pharmaceuticals per redfish caught from nine estuaries on the Gulf and Atlantic Coasts. Tampa Bay’s fish averaged three.
That was the second-highest amount across Florida, behind only Apalachicola with 3.3. In addition to heart medication, the most commonly detected drugs were opioid pain relievers and caffeine.
Adams said, “25% of redfish had levels of pharmaceuticals that would be considered therapeutic.” While the concentrations are below “what a limited number of studies on other species” say is harmful to humans eating locally caught fish, scientists remain unaware of long-term exposure effects.
“We just don’t know,” Adams said. “We also don’t know the interactive effects between these pharmaceuticals and other contaminants that people are exposed to.”
He hopes the latest study also “rings alarm bells” on all water quality issues. Adams said local and state leaders need to significantly upgrade wastewater treatment systems, a common source of contaminants.
He added that the preponderance of drugs found in fish directly correlates to harmful nutrients that cause red tide and other coastal water problems. He called the state’s wastewater infrastructure outdated for the current population, which continues to grow exponentially.
Some contaminants reach Tampa Bay and other estuaries through groundwater, and Adams explained that poses an additional threat to humans who drink well water.
“We’re already behind,” he said. “So, we have a lot more investment to do to catch up.”
However, there is positive news. Adams said his European colleagues have found they can retrofit outdated wastewater treatment facilities with ozonation systems that remove “the vast majority” of pharmaceuticals and other impurities.
He noted that removing toxins from wastewater before it reaches the ecosystem is much easier than mitigating the aftereffects. Converting septic tanks to sewage infrastructure would also help the problem, but he reiterated that many treatment facilities are already over capacity.
“To a great extent, we’re still behaving as if we were 30, 40 years ago,” he said. “When we have a lot more knowledge on how to be in Florida with considerably less impact.”
Adams expressed his hope that the redfish study raises residents’ awareness and that they support politicians and other local leaders who champion wastewater improvements. Conversely, he would like to see more pressure applied to those who drag their feet on the issue.
He said recent state investments are a step in the right direction, but officials must make long-term commitments to mitigate a problem that has worsened after years of neglect.
“We didn’t get here overnight,” Adams said. “It’s going to take some time to dig out of this.”