This circa 2009 photo provided by Bent Christensen show perch fish swimming together in Sweden. What happens to fish that swim in waters tainted by traces of drugs that people take? When it's an anti-anxiety drug, they become hyper, anti-social and aggressive, a study found. They even get the munchies. It may sound funny, but it could threaten the fish population and upset the delicate dynamics of the marine environment, scientists say. The findings, published online Thursday, Feb. 14, 2013 in the journal Science, add to the mounting evidence that minuscule amounts of medicines in rivers and streams can alter the biology and behavior of fish and other marine animals. (AP Photo/Bent Christensen) less
