How do you kill a 30,000-kilogram whale, beached on the sand? A high-powered rifle won't do it, and an injection takes too long.

Western Australia's Department of Parks and Wildlife (DPAW) has the solution — you blow it up.

They are the only state in Australia using an implosion technique to end the suffering of sick or stranded beached whales with explosives detonated near the head of the mammals.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 8 minutes 11 seconds 8 m Doug Coughran, senior wildlife officer with the Department of Parks and Wildlife explains the use of explosives to kill sick and stranded whales is the most humane way. Download 3.8 MB

"We've developed an implosion technique, which is a detonation of a charge that focuses energy to the brain, and there is no quicker result than that method currently globally," Doug Coughran, senior wildlife officer with DPAW said.

Since 1989, 146 humpback whales have been recorded stranded off the West Australian coast.

Of those, 50 were found on the beach alive, 26 died soon after and 16 were euthanased.

Crowds try to save a baby killer whale beached on Back Beach in Bunbury in September 2015. Not all rescue missions are successful, however, resulting in suffering and death of the mammal. ( Supplied: DPAW )

The process leading to euthanasing a whale follows a professional and clinical assessment and in most situations, the decision is based on the perceived degree of suffering and the chances of recovery.

According to explosive expert Ian Styles, if an animal is severely injured and suffering, this procedure is the most effective way to end suffering quickly.

"We place the charge on top of the whale's head, a bit back from the blow hole; the aim is to penetrate the blubber and the cranium," Mr Styles said.

"The skull on a whale is quite thick and it's virtually impossible to shoot it with a high-powered rifle, so we have to use explosives."

Mr Coughran said the technique was internationally endorsed and accepted.

"The detonation is so instant, it's all over in a nanosecond," he said.

Volunteers tried to help a stranded baby sperm whale on a beach in northern New South Wales in 2010, but vets confirmed the animal had no chance of survival and decided that the most humane decision was to put the animal to sleep. ( Michael Jarman: NSW Parks and Wildlife )

In the US injections and drugs are sometimes used to euthanase and they do get a result — slowly.

"When you're dealing with 40,000 kilos of animal, it's not that easy," Mr Coughran said.

"The drug doses are massive and you're left with 40 tonnes of poisonous bait.

"Our implosion technique has been the most humane."

Mr Coughran said his team was responsible for monitoring whale beachings along the entire Western Australian coastline.

He believed the state was a leader in both carcass disposal and humane response protocols.

"It's not a nice thing to do, but when we're faced with it, we're better off understanding how to do it correctly, humanely and instantly [and] to reduce the suffering of the whale as humanely as possible."