Researchers at Monash University have found the behaviour of fish can change if they ingest pharmaceuticals, such as antidepressants that have been incorrectly disposed of.

Key points: Research finds antidepressants in waterways can affect the social behaviour of fish

Research finds antidepressants in waterways can affect the social behaviour of fish Marine life has been found with abnormalities, including genital defects, thought to have been caused by contraceptive drugs

Marine life has been found with abnormalities, including genital defects, thought to have been caused by contraceptive drugs One researcher says pharmaceutical companies need to think more about what happens to drugs once we've taken them

The research published in the Biology Letters journal revealed that psychoactive pollutants can change the behaviour and mood of wildlife — just like it does to humans.

Monash University Professor Bob Wong said the research focused on many different pharmaceuticals including antidepressants, such as Prozac.

"In Prozac, the active ingredient is Fluoxetine and it's been found in habitats around the world including here in Australia," he said.

"The thing with most pharmaceuticals is that the receptors that the drugs are designed to target tend to be evolutionarily conserved among different animal groups.

"That means medicines that have been developed for humans can also have an effect on other non-target species."

A mosquitofish under the microscope, as researchers monitor how the fish behave in isolated and social environments. ( Supplied: Jake Martin )

Professor Wong said the results were alarming.

"What we found was that exposure of mosquitofish to Prozac actually disturbs the normal group foraging behaviours of these fish," he said.

"That can affect the survival of these fish given foraging for these fish is obviously very important to being healthy and being able to survive.

"Exposure of fish to antidepressants disturbs ecologically important behaviours, such as escaping from predators."

Professor Leusch specialises in the impacts of environmental contaminants. ( Supplied: Frederic Leusch )

Professor of Environmental Sciences at Griffith University Frederic Leusch said the research was unique because it focused on the impacts of pharmaceuticals on an organism in a social environment.

"This study is really quite interesting because it's taken that one step further. It looks at behaviour but in a social grouping," he said.

"This test, more representative of the real world, actually allowed those researchers to detect an impact of the exposure.

"I did notice the change wasn't really pronounced — even at the high dose of Fluoxetine, which is a very low concentration.

"The effect is not dramatic, [but] it's scientifically and statistically significant

Unintended consequences

Professor Wong said research conducted in Victoria at Monash University last year found that multiple species had ingested antidepressants.

"They are showing up in the tissues of stream invertebrates and they're also turning up in the tissues of spiders that are living near the water," he said.

"It's actually moving from the aquatic realm into the terrestrial realm because these stream insects emerge, obviously contaminated.

"These researchers also estimated that, based on how much platypuses are consuming, some platypuses in some of these streams will be consuming almost half a human daily dose of antidepressants every single day — that's really alarming."

Australia's waterways are being contaminated with pharmaceuticals that make it through wastewater treatment plants. ( Supplied: David Rennie )

Abnormalities of marine life genitalia

Other research conducted in the United States and elsewhere has revealed that the genitalia of marine life could be altered, if the animal was exposed to certain drugs.

"The one [pharmaceutical] that has received a lot of interest has been the active ingredient of the contraceptive pill, which is a synthetic estrogen," Professor Wong said.

"It's known as an endocrine-disrupting chemical because it can disturb the normal hormone functioning of organisms.

"Sometimes you end up having species that have developed abnormal genitalia as a result of exposure, so feminising of male fish and even male alligators.

"Alligators in the United States have been found with genital deformities presumably because of exposure to things like the contraceptive pill."

Professor Leusch says pharmaceutical companies should investigate the ecological toxicity of medicines. ( Supplied: Pixabay )

A difficult situation

Professor Leusch said there was no easy solution to stopping drugs from entering the waterways.

"Piece one of the puzzle is: can we further improve the removal of pharmaceuticals in waste water treatment plants?" he said.

"The second piece is we consumers of these drugs have to think a bit more before popping a pill.

"The third piece of the puzzle, which is really important, is that there is very little emphasis put on pharmaceutical companies to look at the impact of the products once we've taken them."

Professor Leusch called this the "whole lifecycle assessment".

"Some pharmaceuticals such as the active ingredient in birth control pills are probably 50 to 60 per cent excreted in our urine," he said.

"We're basically medicating our waterways with everything that we put through the wastewater treatment plant."