A recent study found Niagara River fish are absorbing anti-depressants from sewage discharge. Other research determined this isn’t a good thing.
In the study Selective Uptake and Bioaccumulation of Antidepressants in Fish from Effluent-Impacted Niagara River, researchers from the State University of New York at Buffalo looked at both anti-depressant levels in the water and in fish samples.
These chemicals were found at levels in parts per billion at the site of wastewater treatment plants and parts per trillion concentrations at sites in the river away from the plants.
The major contaminants found were the anti-depressants citalopram, paroxetine, sertraline, venlafaxine, and bupropion. The antihistamine diphenhydramine was also detected.
Fish species containing contaminants included largemouth and smallmouth bass, walleye, steelhead, rock bass, and rudd.
Smaller concentrations were also found in yellow perch. Norsertraline, a component in anti-depressants, and diphenhydramine were found in all fish samples.
Separate studies have shown anti-depressants can impact fish survival through changes in behaviour such as predator avoidance, feeding, and a change in aggressive behaviour.
British biologist Alex Ford from the University of Portsmouth has been a lead researcher on the impacts of anti-depressants on aquatic life. While there is no evidence of anti-depressants affecting aquatic life in the field, he said laboratory studies suggest there are impacts.
“The problem we currently have is providing the proof,” he said. “With estrogenic drugs, it was relatively easy to tell when a fish was feminized by taking samples upstream and downstream of wastewater effluent, or clean and polluted estuaries.
With drugs which alter behaviour, providing this proof is far more difficult as you can’t take a blood or tissue sample, and measuring behaviour is tricky in the field.” He is hopeful emerging technology will assist with tracking behavioural changes in the field