Some of this stuff can get scary. I did my master's thesis on endocrine disrupting effects drugs and fertilizers can have on fish physiology. There is a ton of published research showing a great deal of physiological and behavioral changes that can result... Scary thing is, we drink, bathe, and cook with the same water they are swimming in. Granted we are not exposed to these chemicals as long as fish are, the chemicals themselves are very potent. Just something to think about... didn't mean to sound preachy or environmental extremist!