A Natural Resources Defense Council report indicates the use of dogs to harass gulls has helped reduce water contamination levels at Chicago-area beaches.
The border collies being used at the beaches are trained to distinguish gulls from other birds. They are used from dawn to dusk to chase away gulls, the droppings of which contribute to E. Coli contamination.
According to the NRDC, the use of dogs in 2008 at Jackson Park in Chicago resulted in a significantly smaller percentage of days on which water contamination exceeded state standards.
When collies weren't used the following year, contamination levels climbed, and in 2010, when the collies were used again, levels fell again.
Chicago Park District spokeswoman Zvez Kubat says the dogs will be used again this year at South Side beaches.