Whales stranded at Farewell Spit. Credit: Twitter / Project Jonah.
Most of a pod of whales stranded on the South Island's Farewell Spit, at the northern end of Golden Bay, died overnight, the New Zealand Herald says.
This comes after Department of Conservation Takaka operations manager Dave Winterburn said he had received reports of a mass stranding of 36 whales at 6 pm yesterday and had sent rangers to investigate.
The whales were found and the 31 dead were confirmed by Project Jonah senior medics and Department of Conservation rangers in a series of tweets on social media.
Project Jonah also reported five whales had survived the night and were being observed and analysed to "determine if they are candidates for a refloat," with a spotter plane searching around the bay for any other stranded whales.
Project Jonah's Marine Mammal Medics are on standby but are not yet mobilised, and no additional help is being requested at the moment.