A massive sperm whale that washed up near a popular Nelson beach may be left to rot because it is too big to move.
The 18.2-metre behemoth weighs maybe more than 50 tonnes and two large diggers were unable to move and bury it near the Blind Channel end of Rabbit Island, says the Department of Conservation's Chris Golding.
"It's a really large animal so we're going back to the drawing board and see what we can do from here," he says.
It's unclear why the whale came into such shallow water, but one zoologist believes oil and gas research may be to blame.
The whale died almost a week ago, after becoming stranded at Rabbit Island.
Marine Mammal Scientist Simon Childerhouse says the whale's cause of death is not yet known.
"There is a whole range of factors that could have contributed to its death. There's certainly no external signs on the animal to suggest any indication of boat strike or anything like that."
Otago University Zoology Professor Liz Slooten believes seismic research may have played a part.
"Both sperm whales and beaked whales are really susceptible to noise and this kind of reaction where they run away from the noise and run ashore is a common response."
But DoC says it could have died from natural causes.
Today local iwi removed the whale's jaw bone, which along with its teeth, is used for carving.
"The life-force of that whale will continue on," says spokesperson Barney Thomas.
"It's a bit like a tangi - like a funeral. So we treat the whale with that significance."
Doc is now trying to come up with a "plan b" as to how it will move and then bury the mammal.
But they say one option could be to just leave it tied down where it is and let the tide break it down naturally over time.