Tipsy Fish

http://science.time.com/2013/02/15/tipsy-fish-when-anti-anxiety-meds-get-into-rivers/
Veronique Greenwood, Time
February 15, 2013

Summary:

Many drugs, such as antidepressants, make their way into different bodies of water. To test the toxicity of these, scientists from the Umeå University in Sweden conducted experiments with a species of fish, known as perch, living downstream from a factory treats waste water. The scientist discovered that the toxins were accumulating in the muscle tissue of the fish. For oxazepam, an antidepressant drug, six times the concentration in the water was found the the cells of the fish. In order to test the effects of this toxin, a school of perch were split into three groups: one that would continue living in fresh water, one that would live in conditions similar to that in the river, and one that would live in water with five hundred times the river's concentration. Before and after the one week treatment, the fish took a behavioral test. The results showed that fish living in clean water did not have a change behavior. The ones that were exposed to the river conditions spent much less time around other fish and also ate zooplankton more quickly. The main difference between fish exposed to the high concentration was their bravery. They became almost fearless, a bad trait for these small school fish.

Connection:
This relates to our studies on animals because perch are multicellular organisms that are bilaterally symmetric, a topic included in the unit. In addition, this animal is motile and has the ability to move around in the water. Finally, perch is part of the phylum Chordata, which is also part of the unit.