Oct 25, 2010
Contamination of British coastal waters with antidepressants is likely changing the behavior of prawns and other marine life, according to a study conducted by researchers from Portsmouth University.
In recent years, scientists have become increasingly aware that pharmaceutical products and byproducts are contaminating the world’s fresh- and saltwater. These come from products washed off human bodies and clothing, partially metabolized drugs given to humans and animals, and unmetabolized drugs  discarded from hospitals and pharmaceutical plants.
“It’s no surprise that what we get from the pharmacy will be contaminating the waterways,” researcher Alex Ford said.
“Drugs are partially broken down in the treatment process but what we are realizing now is that a lot more gets through than we thought,” Ford  said. “The treatment plants weren’t designed to break down medicines so some inevitably get concentrated [and] released into streams or onto beaches. Effluent is concentrated in river estuaries and coastal areas, which is where shrimps and other marine life  live – this means that shrimps are taking on the excreted drugs of whole towns.”
To test the possible effects of this pollution, Ford and colleagues exposed prawns to the same levels of Prozac  found in British wastewater. They found that the animals, which normally prefer hiding in dark places, became five times more likely to swim up toward light after drug  exposure — thereby placing them at increased risk of being eaten by predators.
“Crustaceans are crucial to the food chain,” Ford said. “If behavior  is being changed this could seriously upset the balance of the ecosystem.”
The researchers believe that, as in humans, Prozac is likely affecting the levels of serotonin in the brains of aquatic animals. The effects of other drugs — such as hormones, cholesterol drugs and antibiotics — remains unknown, as does the effect of drugs in combination.