Fun with Science Club®


			Fish on drugs? Beth Tyler 05.25.01 Many rivers and lakes contain pollution from surrounding cities. Heavy metals and other chemicals flow into the water, having many harmful effects on the plants and animals in it. Mercury is one metal that comes from coal-burning power plants and has serious effects on nearby lakes and rivers. Mercury in lakes actually changes brain function in fish, making them slower and clumsier. Some environmental scientists wanted to study the effects mercury and other heavy metals had on mummichog fish (Fundulus heteroclius behavior. They observed and measured the mummichogs in two creeks in New York, one clean creek and one polluted creek with mercury and other harmful chemicals in it. The mummichogs in the polluted lake were smaller, grew slower, died younger, and caught less shrimp, their main food source, than the mummichogs in the clean creek. To make sure these differences were due to the pollution, the scientists put mummichogs from the clean creek into a tank filled with water and shrimp from the polluted creek. After one month, the fish in the tank behaved like the fish in the polluted creek: they were slower and had a difficult time catching shrimp. This means that the pollution in the creek caused the differences in behavior. Many polluted rivers and lakes have fish in them that humans eat. Along with the fish, then, humans are eating mercury or lead or other harmful chemicals from the water. Scientists have known for a long time that heavy metals are bad for people. For this reason and many more, keeping water clean is as important for humans as it is for fish and other aquatic creatures.


			Weish, Judith S., Graeme Smither, Tong Zhou, Celine Santiago-Bass, and Peddrick Weis. 2001. Effects of contaminants on behavior: biochemical mechanisms and ecological consequences. BioScience 51(3): 209-217.