Global ecosystem threat: fish in lakes and rivers contaminated with antidepressants

Doctors find traces of antidepressants in the brains of fish
The use of antidepressants has continued to increase in recent years. These drugs are mostly used to treat depression and other mental illnesses. Researchers have now found that using antidepressants could change our entire ecosystem.

The University of Buffalo scientists found that small amounts of antidepressants get into our lakes and rivers and affect water quality there. Traces of various antidepressants have been found in the brains of several species of fish that live in large lakes. The doctors published the results of their study in the English-language journal "Environmental Science and Technology".

Despite the treatment of the wastewater, antidepressants get into lakes and rivers
An increasing number of people are taking so-called antidepressants. Of course, residues of these drugs must be excreted from the body. This is how the medication ends up in our toilets, from where it is passed on to a wastewater treatment process in sewage treatment plants. Even after such treatment, it is possible that antidepressants get into our rivers and lakes, the experts explain.

Zoloft, Prozac, Celexa and Sarafem have been found in the brains of fish
When studying the brains of fish species in large lakes in America, the researchers discovered a high concentration of active ingredients in popular antidepressants and also in so-called metabolites (by-products). The antidepressants found in brains included Zoloft, Prozac, Celexa and Sarafem, the scientists explain.

Water pollution poses a threat to biodiversity
The species affected include, for example, fish species such as white and yellow perch, stone perch, zander and bald hake. The concentration found is not potentially harmful to humans, but antidepressants in water should definitely be seen as a problem, explains author Diana Aga of the University at Buffalo. "We should be very concerned because contamination of the water with antidepressants poses a threat to biodiversity," added the expert.

Antidepressants in water change the behavior of shrimp
Previous studies had already shown that antidepressants in the water, for example, induce shrimp to commit suicidal behavior. The shrimp swim towards the light instead of swimming away from the light. This makes them more susceptible to predatory fish and birds, explains Professor Aga.

Antidepressants influence the eating behavior and survival instinct of fish
Other research has shown that antidepressants affect fish eating and survival instincts. For example, some fish no longer respond appropriately to the presence of predatory fish. These effects have the potential to affect sensitive ecological balances in large lakes, which are already besieged by invasive species, the doctors explain. Ultimately, this could even affect recreational fishing in such waters.

In the U.S., more and more people are taking antidepressants
In the United States alone, antidepressant use increased 65 percent between 2002 and 2014. Remnants of the medication are excreted with the human faeces and get into rivers and lakes and finally into the fish.

Fish take antidepressants straight from the water
Before the study, the scientists suspected that the higher concentration of the drugs in large predatory fish is caused by the so-called bioaccumulation. This process describes the accumulation process of pollutants when large fish eat medium-sized fish, which in turn eat small fish. But the current study found that the fish did not ingest the antidepressants by eating small fish, but they take the medication straight from the water.

Sewage treatment plants should also remove antidepressants from wastewater in the future
Sertraline, the active ingredient in Zoloft, was found to be at a concentration twenty times higher than normal. Concern about the pharmaceutical contamination of lakes and rivers has justifiably risen sharply since the use of prescription drugs has skyrocketed, the authors say. In addition, we now have the technological capabilities to detect very small amounts of medication in water. Most wastewater treatment plants are not designed for such drugs, they are more specialized in killing E. coli bacteria. If the negative effects of antidepressants on the ecosystem by the U.S. Environmental Protection Agency or the Michigan Department of Environmental Quality have to be certified, sewage treatment plants for these drugs will urgently need to be developed in the future, according to the researchers. (as)

Author and source information

Video: The extreme side-effects of antidepressants - BBC News (October 2021).