The British military has published in the journal Nature the results of a series of experiments with sonars. The goal was to know how much sonar affects cetaceans. It was known that strong sonars cause great harm to animals, and from the results of current experiments it follows that they also affect low-level sonars. In some cases it prevents them from eating properly and in the long run they may starve.
Although many details of the experiments have remained secret, the data presented by the military shows that it is a worrying problem. They have followed whales with submarine hydrophones to know how they respond to sonars. Low sonars also scare away animals or silence their singing. According to experts, this is because the sound of some sonars is similar to that of predators.