Nine orca whales have died after stranding on a beach at Tuatapere on the Southland coast.
Orca Research Trust founder Ingrid Visser said the stranding was a tragedy as New Zealand's orca population was fewer than 200.
Most of those were individually known to Ms Visser, who had extensively photographed the species.
"Each individual orca looks completely different and the thing is that you can identify them as individuals," she said.
"I have a catalogue that has the individuals of the New Zealand population in it, so by taking photographs we can recognise who the individuals are and know more about what's going on."
Orca strand rarely, and there were only three other known cases of it happening in New Zealand, she said.
Ms Visser was on her way to the scene, where local iwi were gathering to bless the site on Wednesday.
The Department of Conservation had removed one of the whales from the beach.