What happens to beached whales?
Every year thousands of whales are found stranded on beaches all over the world. But how do they get there? And what happens once they hit the shore?
A team effort
Earlier this month, locals in Aceh, Indonesia, teamed up to try and help 10 sperm whales that beached themselves in shallow waters. Volunteers managed to pull six of the animals back out to sea, but four died. There is no real consensus on why whales become stranded, but there are plenty of ideas...
Follow the leader
Some whale species live in social groups known as 'pods', each of which has a leader the other animals swim behind. If the lead animal finds itself close to the shore and in trouble, it can send out a distress signal. The whales following behind may try to help and end up stranded themselves. There is also the possibility that whales become caught while chasing prey.
Manmade strandings
Another school of thought on why whales become beached suggests that overfishing forces the marine mammals to seek food in unfamiliar and potentially shallow waters where they become trapped. There is also some evidence that naval sonar can disrupt and confuse the animals while migrating.
Evading the deep
If a whale perishes deep in the murky depths of the sea, its body sinks to the bottom providing nourishment for a plethora of other animals and organisms for years, even decades to come. But those already close to the shore, may wash up on the beach, like this whale that appeared in Rio de Janeiro. If this happens, the animals decompose on the sand - a phenomenon that can cause other problems.
An explosive response
Though these sunbathers appear undeterred, the stench of a putrifying whale carcass would be enough to put many off their holiday. And the smell is not the only issue. When one of these ocean giants dies and begins to decompose, gases build up in its stomach where they are trapped by a thick layer of blubber. If humans climb on, or try to move the dead whale, it can explode.
A sandy grave
Disposing of a whale that has washed ashore can be a difficult task. Because they can pose a risk to public health, leaving them to rot on the beach is not an option. The best way, say some environmentalists, is to bury them on the beach itself, as was the case with the four whales that died in Aceh.