Sept. 1 (UPI) — If the fish in the Great Lakes seem perkier than usual, it may be because their serotonin levels are being artificially bolstered by large doses of antidepressants.
New analysis of brain tissue from several dozen Niagara River fish, comprising 10 different species, revealed elevated levels of antidepressants, drugs used to treat anxiety and depression. And that’s a significant problem.
“These active ingredients from antidepressants, which are coming out from wastewater treatment plants, are accumulating in fish brains,” Diana Aga, a chemist at the University of Buffalo, said in a news release. “It is a threat to biodiversity, and we should be very concerned.”
Existential dread can be debilitating for humans, and sometimes drugs can be a suitable antidote. In fish, however, antidepressants can encourage lethargy and stunt their interest in hunting, avoiding predators and finding a mate.
The latest study didn’t look at the ecological effects of antidepressants, but previous studies have shown the drugs have a measurable impact on fish behavior.
“The levels of antidepressants found do not pose a danger to humans who eat the fish, especially in the U.S., where most people do not eat organs like the brain,” said researcher Randolph Singh. “However, the risk that the drugs pose to biodiversity is real, and scientists are just beginning to understand what the consequences might be.”
Researchers found antidepressants and their metabolized byproducts in the brains of all the fish species included in the study. The highest concentrations were measured in rock bass.
Scientists found sizable concentrations of the metabolized ingredients found in drugs including Zoloft, Celexa, Prozac and Sarafem. Some specimens boasted concentrations as great as 400 nanograms per gram of brain tissue.
They shared their findings this week in the journal Environmental Science & Technology.
As the use of antidepressants becomes more common among human populations, researchers say wastewater treatment plants may need to think about new techniques for decontamination.
“These plants are focused on removing nitrogen, phosphorus, and dissolved organic carbon, but there are so many other chemicals that are not prioritized that impact our environment,” Aga said. “As a result, wildlife is exposed to all of these chemicals. Fish are receiving this cocktail of drugs 24 hours a day, and we are now finding these drugs in their brains.”
