It is often very difficult to determine the cause of a whale stranding, however, there are several plausible explanations for at least some of the whale strandings that occur:
- Faulty navigation: many of the whales that are found stranded normally live in the open ocean and are not experienced at navigating in the shallower waters of the coastline. Ocean-dwelling whales often use sonar to navigate but they may receive confusing signals near the coastline, especially if they encounter gently sloping beaches. There is also some evidence that naval sonar may also interfere with whale navigation.
- Disease: many stranded whales have been found to be suffering from severe or terminal disease.
- Pursuit of prey: whales that pursue their prey close to the shoreline may become trapped in shallow waters by receding tides.
- Assisting other animals in the group: many whale species live in complex social groups. It is thought that some mass strandings occur when one member of the group has become stranded and the others have responded to its distress signals.