By Susan Milius
Whale-watcher boats may be making so much noise that killer whales off the coast of Washington have to change their calls to communicate over the racket.
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2004/04/4046.jpg?resize=300%2C198&ssl=1)
Recordings made during the past 3 years, after a boom in whale watching in Washington State, show that killer whales lengthen a characteristic call by about 15 percent when boats cluster around them, reports Andrew D. Foote of the University of Durham in England.