Pilot whale pods have been known to follow a sick leader into shallow water where they often die. Dolphins have also been found stranded in large numbers on the east coast of the United States. Some scientists blame diseases induced by human pollution for this stranding behavior. Large numbers of dolphins are caught in drift nets set out to catch tuna and other fish. Dolphins caught in these nets often cannot get to the surface to breathe, so they drown.
International efforts are under way to stop drift net fishing.
Despite the problems facing toothed whales, bottlenose dolphins are very numerous along the southeastern coast of the United States. They can be seen traveling in small pods near almost any beach or in tidal creeks. The bottlenose dolphin may be the most familiar of all whales since they are common performers at large marine aquariums. Dolphins feed mostly on fish. They can be seen herding fish in teams much like cowboys herding cattle.