A group of researchers found concentrations of human antidepressants in 10 types of fish in the Great Lakes region. The new study claims several types of antidepressants were found in fish in the Niagara River, which connects Lake Erie with Lake Ontario.

The study was published online August 16 in the journal Environmental Science and Technology and was conducted by scientists at the University of Buffalo.

Image credit: Duluth News Tribune
Image credit: Duluth News Tribune

The researchers found several active ingredients from antidepressant medications, including Prozac and Zoloft. The findings are shedding light on how waste on the Great Lakes region is posing a threat to biodiversity.

Fish in the Great Lakes region have Prozac and Zoloft ingredients in their brains

The study said active ingredients from antidepressants were found to be built up in the brains of smallmouth bass, largemouth bass, rock bass, white bass, rudd, white perch, walleye, bowfin, steelhead and yellow perch.

The researchers say the source of the contamination is wastewater, which has managed to lodge and affect fish across the region.

“These active ingredients from antidepressants, which are coming out from wastewater treatment plants, are accumulating in fish brains,” Diana Aga, the study’s lead scientist from the University of Buffalo, said in a statement from the university. “It is a threat to biodiversity, and we should be very concerned.”

Antidepressants weren’t the only ones to blame, as the scientists said in their study that the release of pharmaceuticals, as well as the release of personal care products into freshwater systems, is affecting the health of aquatic organisms.

The study focuses on the concentrations and bioaccumulation of pharmaceuticals and personal care products (PPCPs) and the presence of antidepressants in several species of fish from the Niagara River, which links two of the North American Great Lakes, Erie, and Ontario.

The scientists noted the Niagara River receives the dangerous PPCPs from several wastewater treatment plants located along the river and Lake Eire. They searched for 22 specific PPCPs in the water samples and found 11 were present in the river.

Image credit: Darron Cummings / AP / US News
Image credit: Darron Cummings / AP / US News

Drugs could affect feeding behavior or survival instincts

Overall, the major pollutants were the antidepressants, which are causing behavioral problems on these fish.

“These drugs could affect fish behavior,” said Aga. “We didn’t look at behavior in our study, but other research teams have shown that antidepressants can affect the feeding behavior of fish or their survival instincts. Some fish won’t acknowledge the presence of predators as much.”

Aga noted that the levels of antidepressants found in fish do not pose a threat to humans who eat them, especially in the United States, where most people don’t eat the fish organs like the brain. But she stressed the risk that these drugs pose to biodiversity is real and said that scientists are only beginning to understand what the consequences might be.

Aga and her colleagues said this is a field of growing concern, particularly because the use of antidepressants has been increasing throughout the region. For instance, the National Center for Health Statistics estimates the percentage of Americans taking antidepressants jumped 65 percent between 1999-2002 and 2011-2014.

The scientists noted that most wastewater facilities are failing to keep pace with this growth and typically ignore these drugs, which are then released into the environment and latch onto fish or other animals.

Antidepressants are ‘largely ignored’ by wastewater treatment plants

According to the researchers, the highest concentration of a single ingredient was found in rock bass, as they found it had about 400 nanograms of norsetraline (one of the active ingredients in Zoloft) per gram of brain tissue. Unfortunately, that wasn’t even the only drug found in rock bass, as they also tested positive for citalopram, the active ingredient in Celexa, and norfluoxetine, a metabolite of the active ingredient in Sarafem and Prozac.

Aga noted that more than half of the fish brain samples had norsetraline levels of 100 nanograms per gram of tissue or higher. Moreover, many of the fish had a cocktail of antidepressant drugs and metabolites in their brains.

The researchers said that scientists had not done enough research yet to determine what amount of antidepressants poses a risk to animals, or how they can influence their behavior. Aga also said the study had raised concern regarding wastewater treatment plants, whose operations are damaging the biodiversity of fish in the Great Lakes region.

Aga explained that, usually, wastewater treatment plants focus on killing disease-causing bacteria and extracting solid material like human excrement. However, antidepressants –which are found in the urine of those who take the drugs—are “largely ignored,” along with other compounds of concern that have become “commonplace.”

“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,” said Aga. “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.”

Source: University of Buffalo