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
Captive killer whales a limited area, such as Puget Sound or the Strait of Juan de Fuca, are termed "resident" whales, while "transient" whales roam the oceans at will. These "transient" types have to be more aggressive, in order to assert themselves in a wide range of territories and to prey on a variety of different species. This increased aggressiveness does not disappear in captivity. Furthermore, captivity itself has been asserted to aggravate aggressive behavior, resulting in a "cetacean equivalent of anxiety disorder." Captive killer whale attacks on humans seem to fall mostly into the categories of: biting during feeding, ramming in the