BUFFALO, N.Y. — A new University at Buffalo study reveals a serious threat to fish in the Great Lakes region.

The study published Aug. 16 found high concentrations of antidepressants in the brains of bass, walleye and other types of fish common in the region, according to a news release published on UB's online News Center.

Rock bass were found to have the highest concentration of a single compound — norsertraline, which comes from sertraline, the active ingredient in the drug known as Zoloft.

The drugs are entering waterways via wastewater treatment plants, which are not adequately cleansing water of the drug chemicals before it is discharged back into the environment, says Diana Aga, Ph.D., UB's Henry M. Woodburn Professor of Chemistry and the study's lead scientist.

“These active ingredients from antidepressants, which are coming out from wastewater treatment plants, are accumulating in fish brains,” Aga said. “It is a threat to biodiversity, and we should be very concerned."

She went on to explain the drugs could affect fish behavior, particularly their survival instincts. Laboratory studies have shown the drugs are capable of altering fish behavior, and they accumulate in fish brains over time.

Of additional concern is the sharp rise in the percentage of Americans who use antidepressants, which has increased 65 percent from between 1999-2002 and 2011-2014. Aga says wastewater treatment plants are not keeping pace with the increase.

In addition, fish and other wildlife can be exposed to a "cocktail" of chemicals as wastewater treatment plants generally target bacteria and solid-matter that can cause diseases, while neglecting antidepressants, which are found in the urine of people who use the drugs, as well as other concerning chemicals.

The issue is also made worse by sewage overflows into the Niagara River, according to the study. 2 On Your Side's partners at the Investigative Post recently found more than a half-billion gallons of raw sewage mixed with storm water has entered the Lower Niagara River since May 2016. This investigation stemmed from an inky, smelly black discharge found near the base of Niagara Falls last month.

Scientists from SUNY Buffalo State, Ramkhamhaeng University and Khon Kaen University, both in Thailand, assisted with the study.