What is a stranding?
According to the U.S. Marine Mammal Protection Act, a stranded marine mammal is not only a living marine mammal on land that needs medical assistance or is unable to return to the water without assistance, but also includes any dead marine mammal (at sea or on land).
While it’s fairly easy to determine if a whale or dolphin is stranded, it’s rarely easy to understand why.
There is a species of beaked whale, Perrin’s beaked whale, that was first identified from a few stranded individuals and has only recently been seen at sea!
Types of strandings
This can include a living or dead baleen or toothed whale species and includes either a single individual or a mother and her calf. Since a calf is still dependent on his or her mom, stranding with mom is considered a single event.
Mass strandings primarily occur when 2 or more (not including a mom and calf) whales or dolphins strand together. These are typically social groups of toothed whales (dolphins, pilot whales, sperm whales, etc) who are usually alive when the stranding occurs.
Whales and dolphins are more likely to strand on some types of shore and coastline than others. Shallow, sloping shores made of soft sediment can confuse the “echolocation” used by whales and dolphins to find their way around.
A combination of factors may cause whales and dolphins to strand and one theory relates to them navigating using the earth’s magnetic field. Crystals of magnetite - which react to a weak magnetic field - have been detected in the brains and skulls of some whales and dolphins and a magnetic “sense” could be an important navigational aid, especially in the deep oceans.
Whether caused by human activity or as a result of something natural, strandings are tragic, but they, can tell us a lot, about the biology of the animals, the state of the population it came from and the marine environment.
Make a difference
Join our team - no matter which way you choose, your commitment helps whales, dolphins, and our shared planet.
Save the whales, save the world.
Adopt a whale and help us protect these amazing creatures.
You can join our team and help us save whales and dolphins
Your gifts help us take action for whales and dolphins.
Support WDC by shopping for yourself or a friend.