Beaked whales dive deep, on average 500 to 1,000, or even up to 4,000 metres for long periods, to catch squid and fish. Scientists suspect this is a strategy to avoid being attacked by orcas, which are their main predators. Most beaked whales seem to use their echolocation to find food only when deep enough and out of reach of orcas. Apart from that, they are silent during the dive. Through experiments with sonar and playing back sounds from orcas, scientists suspect that beaked whales interpret this as danger in both cases and flee or stay underwater longer. Staying underwater longer can lead to decompression symptoms and disorientation, resulting in possible stranding events. Strandings on the Dutch coast The southern North Sea is too shallow for beaked whales and submarines. So far, in the few beaked whales stranded on our shores that were fresh enough to be examined further, no evidence of sonar damage has been found. They are often emaciated animals, which have run out of food in the shallow North Sea and died from starvation or drowning. Source: zoogdiervereninging.nl