Fish in the Great Lakes region have been found to have significant traces of antidepressants in their brain. Experts are concerned about the ecological implications of the serious contamination.

Antidepressants In The Great Lakes

A new study found a serious contamination that can be directly linked to human activity albeit in an unusual way. Upon testing, the brains of common fish in the Great Lakes region were found to have high concentrations of antidepressants.

High concentrations of both the active ingredients and by-products of popular antidepressants were found in the tissues of 10 common fish species in the Niagara River which connects two of the Great Lakes: Lake Erie and Lake Ontario. Traces of citalopram, paroxetine, norsertraline, and sertraline were just some of the pharmaceuticals and personal care products (PPCPs) found in the region.

The fish species affected by the contamination are rudd, largemouth bass, smallmouth bass, rock bass, white bass, bowfin, steelhead, walleye, white perch, and yellow perch. The bass had the highest concentration of norsertraline in the brain at 400 nanograms.

How Did This Happen?

As aforementioned, the Niagara River connects Lake Erie and Lake Ontario, but it also receives PPCPs from waste water treatment plants (WWTPs) where people's wastes get processed. Unfortunately, high concentrations of the PPCPs were released into the wild.

It was upon testing for 22 types of PPCPs that researchers discovered high concentrations of 11 PPCPs including antidepressants and the antihistamine diphenhydramine. In fact, concentrations were at parts-per-billion and parts-per-trillion levels.

Implications Of The Contamination

Although researchers do not believe that the contamination is harmful to humans who might end up eating the fish especially since most people in the United States do not particularly eat fish brains, it could be problematic for the balance in the ecosystem and for the fish themselves.

What's concerning for the researchers is the way that the fish are being contaminated. Initially, co-author of the study Diana Aga of the University at Buffalo expected the larger fish to have higher concentrations of antidepressants after eating smaller fish that have also been contaminated. What they found instead was that the fish were not getting contaminated by eating smaller fish, but by merely being in the water.

Although they did not study fish behavior, they pointed out that further studies need to be done in order to fully see the implications of the contamination. This is especially significant because previous studies have shown that antidepressants may affect fish's feeding behavior and survival instincts.

"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," said Aga.

With possible serious consequences, researchers believe that WWTPs also need to take antidepressants into consideration when testing for contaminants especially since the percentage of Americans using antidepressants have increased by 65 percent from 1999 to 2014. As of now, WWTPs only screen for solid waste and treat E. coli bacteria.

The study is published in the journal Environmental Science and Technology.

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