The Farewell Spit stranding is among the largest in history - not just in New Zealand, but worldwide - so why are pilot whales so drawn to this area?
Auckland University marine biologist Rochelle Constantine says this is the third largest mass stranding in our history, and it is "a very large one - logistically it's a massive undertaking".
There are about 85 strandings around New Zealand each year, with hot spots including Ninety Mile Beach, Mahia Peninsula, Stewart Island and Golden Bay.
Farewell Spit's long, protruding coastline is a confusing hazard for pilot whales, with the navigation system - echo location - thought to be less effective near the gentle sloping beaches.
There are also strong local currents around the bay.
About 200 whales stranded on the spit in 2015, more than 40 a year earlier, and about 100 two summers before that.
"They just make a mistake and come into too shallow water," Ms Constantine said.
"They're a strong socially bonded whale and they come together in these large aggregations at this time of year for calving and socialising in all forms and we think its because they get together in these groups we get these large strandings.
"It's a natural event. I think often we look for excuses or reason or meaning behind it but pilot whales have been stranding for years long before humans arrived here so it's not an unusual event."