As human garbage makes its way out into the sea, fish off the coast of Florida are testing positive for a variety of medications.
Since 2018, researchers from Florida International University and the Bonefish and Tarpon Trust, a Miami-based nonprofit dedicated to bonefish and tarpon conservation, have been studying the two varieties of fish that can be found in Biscayne Bay and the Florida Keys.
They took blood and tissue samples from 93 bonefish and tarpon in the area and discovered that each one was using an average of seven pharmaceuticals, including antidepressants, blood pressure meds, prostate treatment pills, antibiotics, and pain relievers.
One fish even had a total of 17 different drugs in its tissues, the study found, and the researchers found pharmaceuticals in the bonefish prey – including crabs and shrimp.
These drugs can affect every aspect of fish life, including their feeding habits, sociability and migratory behavior – threatening the already diminishing bonefish population in the area.
‘These findings are truly alarming,’ Jennifer Rehaga, a coastal and fish ecologist and associate professor at the university said in a statement.
‘Pharmaceuticals are an invisible threat, unlike algal blooms or turbid waters,’ she explained.
‘Yet these results tell us that they are a formidable threat to our fisheries, and highlight the pressing need to address our longstanding wastewater infrastructure issues.’
Researchers found that exposing both individual fish and their social groups – called ‘shoals’ – to different levels of fluoxetine had no apparent effect on solitary fish.
But as a group, the study published in the journal Biology Letters in 2019 found, the mosquitofish relaxed their hunting behavior and ate less food overall when exposed to high levels of the drug – which remains active even in low doses and can be released constantly.
Meanwhile, the study from the Florida International University reports, nearly 5 billion prescriptions are filed each year in the US – with IQVIA reporting that in 2020, a total of 6.3 billion prescriptions were dispensed.
Yet there are still no environmental regulations for the disposal of the pharmaceuticals – which can be released through one’s urine and wind up in freshwater bodies like lakes and rivers because the water treatment systems cannot fully filter out the traces of the drug.