What Happens When Drugs Meant for Humans Get into Lakes and Streams?
by Lucy Benton, age 12
Medications that people use are starting to appear in rivers and streams all over the world. These drugs are negatively affecting the fish living in those waters.
A recent study has shown that the drugs used by humans are changing the behaviors of fish living in areas where these drugs have appeared. For example, anti-anxiety drugs make fish hyper, anti-social, and more threatening. These negative effects could threaten fish populations.
Swedish researchers who conducted the study are predicting that smaller fish exposed to drugs will become easier prey for bigger fish. These little fish that are drugged are more likely to wander into unfamiliar areas, therefore making it easier for bigger fish to catch them.
A scientific team at Sweden’s Umea University put young wild European perch in an aquarium where the fish were exposed to diluted drugs. The team carefully noted their behaviors. Drugged fish moved more, fed more aggressively, hid less, and participated less in schools of fish.
This study shows that increased drug levels in fish habitats can upset the fragile dynamics of marine environments.
[Sources: Associated Press; Wisconsin State Journal]