Crayfish behave more boldly after exposure to antidepressants – study

Traces of drugs found in water can make crustaceans more outgoing - but also vulnerable to predators

Antidepressant drugs in water can alter the behaviour of crayfish, making them bolder and more outgoing, and therefore more vulnerable to predators, researchers have found.

Low levels of antidepressants - excreted by humans or disposed of incorrectly - are found in many water bodies. Researchers from the University of Florida assessed the impact of these medicines on crayfish, which are a fundamental component of many aquatic food webs - given they eat almost everything, from plants, insects, leaf litter to small fish (even cannibalising each other).