Whale food chain. They have large reserves of blubber, more so for toothed whales as they are higher up the food chain than baleen whales. Lactating mothers can pass the toxins on to their young. These pollutants can cause gastrointestinal cancers and greater vulnerability to infectious diseases. They can also be poisoned by swallowing litter, such as plastic bags. Advanced military sonar harms whales. Sonar interferes with the basic biological functions of whales—such as feeding and mating—by impacting their ability to echolocate. Whales swim in response to sonar and sometimes experience decompression sickness due to rapid changes in depth. Mass strandings
Toothed whale stunned fish. Coralling is a method where dolphins chase fish into shallow water to catch them more easily. Killer whales and bottlenose dolphins have also been known to drive their prey onto a beach to feed on it, a behaviour known as beach or strand feeding. The shape of the snout may correlate with tooth number and thus feeding mechanisms. The narwhal, with its blunt snout and reduced dentition, relies on suction feeding. Sperm whales usually dive between , and sometimes , in search of food. Such dives can last more than an hour. They feed on several species, notably