13/02/2017 3:40 PM AEDT | Updated 13/02/2017 3:58 PM AEDT

Whale Clean-Up Starts In New Zealand After Mass Beachings

Anthony Phelps / Reuters
Volunteers try to guide some of the stranded pilot whales still alive (in background) back out to sea after one of the country's largest recorded mass whale strandings, in Golden Bay, at the top of New Zealand's South Island, February 11, 2017. REUTERS/Anthony Phelps

A macabre clean-up has begun at New Zealand's Golden Bay after hundreds of beached whales died in one of the nation's largest mass strandings in history.

Around 600 whales stranded themselves at the picturesque location at the top of New Zealand's south island in a series of mass beachings last week.

Authorities and volunteers worked frantically since Thursday to re-float as many of the pilot whales as possible, but sadly around 250 died, according to media reports.

The operation has now moved to a clean up phase, with New Zealand authorities reportedly cutting holes in the dead animals and popping them "like balloons" so they do not explode.

The ABC reports that workers on Monday have been using two-metre-long needles to undertake the grim task that releases the pressure in the carcasses from internal gases.

"The area is currently closed to the public because of the risk from whales exploding," the conservation department is quoted as saying in a statement.

It will be some time before the area returns to normal, with it is said to take numerous months for whale carcasses to decompose and turn into skeletons.

Mass beachings are not uncommon at Farewell Spit where the gradient of the sandy shore is thought to disrupt whales' echolocation.