Flushed drugs leave limpets unable to cling on to life

Medicines dumped in the water system are having a harmful effect on shellfish and other aquatic species

LIMPETS are being killed due to a rise in antidepressants found in UK waters, scientists have warned.

A study argues that aquatic creatures are “bathing in a soup” of the drugs – which means they are no longer able to cling on to rocks – after prescription rates doubled in the last 10 years.

Experts have called for doctors to consider the effect on the environment before offering medication such as Prozac, saying their presence in the ecosystem can affect everything from a creature’s growth to its feeding habits.

They also point to research indicating that antidepressants in waste water have caused shrimps to swim towards light, making them more likely to be eaten by predators.

Similarly, the chemicals have been linked to aquatic species no longer being able to stick to surfaces such as rocks.

It is thought that approximately six million people – around 10 per cent of the population – now take antidepressants regularly.

Published in the British Journal of Psychiatry, the new study calls for an overhaul of the UK’S waste water system to bring chemical levels to within legal levels, as well as encouraging patients to return unused medication to pharmacies rather than flushing it down the lavatory.

Prof Alex Ford, of Portsmouth University’s Institute of Marine Biology, said: “Antidepressant and anti-anxiety medications are found everywhere – in sewage, surface water, groundwater, drinking water, soil and accumulating in wildlife tissues.

“They are found in seawater and rivers and their potential ability to disrupt the normal biological systems of aquatic organisms is extensive. This isn’t about a one-off pollutant entering their habitat; wildlife are bathed in drugs for their entire life cycle.

“Laboratory studies are reporting changes such as how some creatures reproduce, grow, the rate at which it matures, metabolism, immunity, feeding habits, the way it moves, its colour and its behaviour.”

Scientists believe that aquatic organisms can be affected by as little as one nanogram of the drugs per litre, the equivalent of a few drops of water in an Olympic-size swimming pool.

“Pharmaceuticals that are found in relatively low concentrations could be extremely potent and very persistent,” added Prof Ford.

It is thought that just as antidepressants affect hormones such as serotonin in the human brain, they affect invertebrate creatures too.

The researchers suggest that the increase in antidepressant use is partly due to the difficulty in securing psychological counselling in the UK.

They argue that prescribing the drugs should be reduced in favour of counselling, as far as is safe for patients.