Why do whales explode?

Just why do whales explode? What causes these giants of the sea to fill ip with gas when they die? Stuart Blackman explains

Published: Thursday, 28 December 2023 at 07:00 AM

Do whales explode? Type ‘exploding whale’ into your search engine and you will be rewarded with material that is not for the faint-hearted.

Yes, exploding whales really are a thing. For the record – and to put your mind at ease just a little bit – we are talking dead whales here. Nevertheless, you have been warned. Here is why whales explode…

It usually starts with a whale carcass washing up on a beach. Most whales sink to the seabed when they die, where they provide a bonanza resource for marine scavengers – sharks, hagfish, crabs, eels and specialist bone-eaters such as Osedax zombie worms.

There are scavengers on land, too, for whom a washed-up whale presents the opportunity of a lifetime. But while a flock of gulls can make short work of a dead bird or a discarded bag of chips, a dead whale presents a far bigger challenge, and nature’s clean-up operation inevitably takes longer.

As decay sets in, gases from the decomposition process build up inside the body causing a rise in internal pressure. And whale skin can withstand a lot of pressure.

Left alone, these gases usually leak out eventually without excitement. However, the process has been known to end in more spectacular fashion when humans have got involved. Play with balloons and it’s not unlikely that some will pop. And balloons don’t get much bigger than a gas-filled whale.

In 2004, for example, the BBC reported on a dead sperm whale that exploded while being transported on a trailer to a research centre in the Taiwanese city of Tainan, soaking cars and pedestrians in blood and organs. Another celebrated example – again a sperm whale and documented on video – occurred on the Faroe Islands, when a biologist cut into the animal in an attempt to release the gases in a controlled manner.

The idea of exploding whales has caught on to the extent that just the anticipation of such an event is enough to generate news stories, as happened in 2014, when a blue whale washed up in Newfoundland, Canada. No doubt, many were disappointed when it simply deflated slowly.

But perhaps the most famous example involved dynamite rather than gas pressure. Controlled explosions are not an uncommon method of disposing of whale carcasses on popular beaches to deal with the smell and risk of disease. By dispersing the flesh in small fragments, it can be more easily dealt with by scavengers.

But it doesn’t always go according to plan, especially when too much explosive is used. As one reporter described, while covering the disposal of a sperm whale in Florence, Oregon, in 1970, “the humour of the situation suddenly gave way to a run for survival as huge chunks of whale blubber fell everywhere. Pieces of meat passed high over our heads, while others were landing at our feet.” A car parked a quarter of a mile away was flattened by one chunk. And apparently it didn’t make the beach smell any nicer.