Antidepressants affect aquatic life

The presence of antidepressants in our aquatic ecosystem is threatening wildlife, affecting its behaviour and biological make-up. A researcher from the University of Portsmouth has discovered that lower than expected concentrations of the prescription drugs are necessary to cause these changes. Just as antidepressants affect hormones such as serotonin in the human brain, many biological functions within invertebrates are also under serotonin’s the control. “Many invertebrates such as amphipod shrimp become more active and increase their speed of movement while freshwater snails display altered reproduction and some lose their ability to attach to surfaces,” said Dr Alex Ford, a marine biologist. “Some bivalve species, such as zebra mussels, were induced to spawn when exposed to antidepressants.” Ford said in many invertebrates, serotonin controls the release of certain pigments causing the creature to change colour; one recent study has shown that antidepressants can alter colour changes in cuttlefish. In crabs, it controls aggression, reproduction and development, while the drug also affects growth, feeding and metabolism in other aquatic wildlife. “What we now know is that they can be affected by exceedingly small amounts, as little as one nanogramme per litre – like dropping a few grains of the compound into an Olympic size swimming pool,” Ford said. [caption id="attachment_37915" align="alignright" width="200"] Dr Alex Ford[/caption] “Although concentrations observed in our rivers and estuaries are very small, it’s worrying that an increasing number of studies have shown that these incredibly small concentrations can dramatically alter the biology of the organism they come into contact.” Ford said there is a staggering list of prescription drugs passed from humans to wastewater treatment plants and into receiving streams and estuaries, or oceans by direct consumption, metabolism, and excretion or by toilet flushing of old prescriptions. “A body of evidence is building that suggests antidepressants at concentrations currently found in surface, water and ground water is sufficient to cause a wide variety of effect,” he said. “This is despite the fact that reports indicate these types of drugs make up only 4% of the known pharmaceutical detected in the environment.” Ford’s work has been published in Aquatic Toxicology. The biological effects of antidepressants on the molluscs and crustaceans: a review