14 February 2013
Drug residues 'alter fish behaviour'
By Jonathan Amos
Science correspondent, BBC News, Boston
Tomas Brodin and his lab fish
Psychiatric drugs taken by humans to cope with anxiety are being excreted and flushed into waterways where they are probably affecting fish behaviour.
This is the conclusion of a new Swedish study reported in Science magazine.
The Umea University-led investigation exposed laboratory perch to the drug Oxazepam at levels equivalent to the residues found in rivers and streams.
The fish were found to eat faster, to be less social and to be bolder than animals that were not dosed.
Umea’s Tomas Brodin said the behavioural changes seen in their lab animals could have unexpected evolutionary and ecological consequences if reflected in wild populations.
“The strong behavioural modifications we saw were at low concentrations, and I firmly believe we could go even lower and still see these effects,” the researcher told BBC News.
“We looked at just one benzodiazepine-type drug but there are many others out there, and they probably all have the same effects on fish and other vertebrates. So we may be underestimating what is happening in nature.” (...)
Full text: http://www.bbc.co.uk/news/science-environment-21437404