Fun with Science Club®


			Is sonar bad for whales? Carrie Straight 06.01.01 Many animals on land and in the ocean use sound to communicate. Animals in the ocean use sounds to get around, to detect predators, and prey. With the increasing numbers of people out in the oceans today, the sounds coming from ocean-going vessels might be changing the behavior of whales and other ocean-dwelling animals that depend on sound. Whales use songs during the mating season. Scientists believe that their songs are involved in mate-attraction. The whales sing a series of songs. Some scientists from the United States wanted to learn more about how man-made sounds affect humpback whale (Megaptera novaeangliae) songs. With help from the United States Navy, the researchers went out into the ocean and located humpback whales. They systematically observed and recorded the whales behavior before, during, and after they played some low-frequency active sonar. After listening to the recordings, the researchers found out that the whales sang longer during the sonar playbacks than either before or after the playbacks. The researchers think that the whales might increase the length of their songs to compensate for the interference from the sonar. This change in song length might also change a whale’s ability to find a mate, which would be harmful to whale populations.


			Miller, Patrick, J. O., Nicoletta Biassoni, Amy Samuels, Peter L. Tyack. 2000. Whale songs lengthen in response to sonar. Nature 405: 903.