One fish, researchers say, had 17 different types of drugs in its system, including blood pressure medication, antidepressants, prostate treatment medications, antibiotics and pain relievers. Other noted drugs in researchers' findings include heart medications, antifungal medication and opioids.

"These findings are truly alarming," said Jennifer Rehage, the lead researcher and a coastal and fish ecologist and associate professor at the FIU Institute of Environment, in a statement. "Pharmaceuticals are an invisible threat, unlike algal blooms or turbid waters.