With mental health problems on the rise, more and more medications are finding their way into rivers and estuaries. Scientists are making use of technology to find out how this is affecting wildlife

Antidepressants don’t just affect human libidos. New research shows that female starlings fed food spiked with the antidepressant fluoxetine (Prozac), were less “attractive” to males and so less likely to mate. This is the latest evidence highlighting the potential harm of the drugs that we are releasing into the environment.

Like many drugs we consume, antidepressants that don’t get fully broken down in our bodies are excreted through our urine, from where they find their way to wastewater treatment plants. These facilities don’t have the ability to break down the drugs, which then enter our rivers and estuaries, and come into contact with and build up in our wildlife.

With the numbers of young and old people with mental health problems on the rise, and rapid increases in prescriptions of antidepressants and anti-anxiety medications, these problems of water contamination are set to get worse.

We already know quite a lot about the effects of pollution of animal behaviour. We know that chemicals can alter wildlife’s aggression, ability to smell, courtship and reaction to stimuli such as light. All these behaviours are critical for animals escaping from predators, finding food and mates, or defending territories. But most of this data comes from studies in labs. And an animal’s behaviour is often very sensitive to its surroundings. So to work out exactly how drug pollution is affecting animals in the wild, my colleagues and I have turned to technology to track, measure and analyse their behaviour.

One of the difficulties with this is that animal behaviour often changes quickly and is hard to record without disturbing the specimens you’re trying to monitor, especially in something like a murky river.

To take humans as an example, an individual might not be aggressive or anxious all the time. Their behaviour might alter depending on whether they were in a large or contained space, or the time of day.

If you wanted to measure the “feminising effect” of sewage effluent on fish, you could collect some fish upstream and downstream of sewage facility and dissect them. Or you could take blood samples that give you a snapshot of their physiology over time. Alternatively, you could cage an animal downstream of a sewage treatment plant and take similar measurements.


Source: August 13, 2018, Independent